Charles F. Kettering and the
1921 Discovery of Tetraethyl Lead
In the Context of Technological Alternatives

By Bill Kovarik, Ph.D.

Originally presented to the Society of Automotive Engineers Fuels & Lubricants Conference, Baltmore, Md., 1994; revised in 1999.

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This paper discusses the technological and public health context of the 1921 discovery and subsequent development of the anti-knock gasoline additive tetraethyl lead. The discovery has long been seen as a milestone of systematic research and a vital turning point in the development of modern high compression engines. This paper will show that the choice of tetraethyl lead over other viable alternatives took place within the context of a complex controversy.

One important aspect of the controversy was public. After leaded gasoline entered the market in 1923 - 24, a fatal refinery accident drew news media attention to the poisonous nature of the full strength additive and the potential public health risk from fuel containing the dilute additive. Public health scientists insisted that alternatives existed, but industry in general and GM in particular vehemently insisted that tetraethyl lead was the only additive that could be used.

The controvery was never resolved because until 1991 virtually no primary documentary material was available in public archives. That year, General Motors Corp. released about 80 linear feet (40 file cabinet drawers) of materials from the office of Kettering's research assistant Thomas Midgley. The files date between 1917 and the late 1920s. They are "unclassified," meaning that they have not been fully catalogued, and were released to what was then the General Motors Institute (now Kettering University) in Flynt, Mich. They contain research reports, correspondence and internal memos from the Dayton, Ohio research labs headed by Charles F. Kettering which became the main research arm of the General Motors Corp. in 1919.

The documents reveal a second aspect of the controversy involving the auto industry's long term fuel strategy. At the time, around 1921, Kettering wanted to protect GM against oil shortages (then expected by the 1940s or 1950s). His strategy was to raise engine compression ratios with TEL specifically to facilitate a transition to well known alternative fuels (particularly ethyl alcohol from cellulose). However, Kettering lost an internal power struggle with GM and Standard Oil Co. directors of the Ethyl Corp. Kettering's strategy was discarded when oil supplies proved to be plentiful and TEL turned out to be profitable in the mid-1920s. But Kettering and others in GM clearly did not believe that TEL was the only fuel option.


The discovery of the anti-knock effect of tetraethyl lead in gasoline is among the most celebrated achievements of automotive engineering in the 20th century. It is often portrayed as the result of genius, luck and a great deal of hard work. Leaded gasoline allowed an increase in engine power and efficiency by raising fuel anti-knock quality -- what is today called the "octane rating" based on iso-octane reference fuel.

The discovery has also been one of the most controversial. The 1970s - 1990s controversy over public health impacts of leaded gasoline is well known, but the 1920s controversy is not. When five men died in a New Jersey refinery in October, 1924, a storm of protest and scientific dispute surrounded General Motors, Standard Oil of New Jersey, and E.I. du Pont de Nemours Corp., the three principal developers of leaded gasoline. G.M. and Standard together had formed the Ethyl Gasoline Corp., and du Pont participated as a one-third owner of G.M. and as the largest tetraethyl lead manufacturer.

The refinery workers went suddenly insane from the cumulative effects of intense exposure to concentrated tetraethyl lead. To some scientists, this indicated a potential public health problem even when the additive was diluted 1000-to-one in gasoline. Experts in lead toxicology, such as Alice Hamilton of Harvard University, and respiratory physiology, such as Yandell Henderson of Yale, insisted that allowing the introduction of lead on a widespread basis would be acatastrophic mistake in public health policy.

Charles F. Kettering, vice president for research at General Motors, his assistant Thomas A. Midgley, and others from Standard and du Pont staunchly defended their new product and, as one central premise of the defense, claimed that there were no alternative anti-knock additives available.

Hamilton, Henderson and others insisted that alternatives were available. Yet they did not venture outside their expertise with specifics on the possible alternatives, and the controversy was never resolved. This locus of the historical controversy has never been explored, primarily because archival sources are incomplete. However, in 1991, General Motors released about eighty boxes of unclassified early research division correspondence, mostly from the files of Thomas Midgley, to the GMI Alumni Foundation Collection of Industrial History in Flint, Mich.

Although the record is still fragmented, the new documents form an improved basis for evaluating the interpretations of the discovery of and the controversy surrounding Ethyl leaded gasoline in the 1916 to l926 period.


About a dozen accounts of the discovery of tetraethyl lead have been published in biographies, labor histories and business histories in the past 40 years, but only a few mention the complex web of possibilities facing the G.M. research team in the early 1920s.

Most historians take the technological and business success of tetraethyl lead more or less for granted. For example, Carl Solberg's Oil Power, a highly critical history of oil industry activities in politics, economics and foreign policy, described tetraethyl lead as "Kettering's magic antiknock fluid."1 Labor historians Rosner and Markowitz said that the elimination of engine knock with tetraethyl lead "allowed for the development of the automobile essentially as we know it today." Yet the critical intent is obvious from the title of their 1989 book: Dying for Work.2

Many popular historians ignored the discovery of leaded gasoline and thesubsequent controversy despite their interest in the controversial political and technological aspects of the oil industry. It is not mentioned in John Blair's The Control of Oil, Anthony Sampson's The Seven Sisters, James Ridgeway's Powering Civilization or Daniel Yergin's The Prize.3

On the other hand, historians of technology have been interested in leaded gasoline. Noted historian Thomas Hughes saw the the discovery as an important episode in the history of invention which could be located in the transition between the "heroic" 19th century style of invention and the anonymous, corporate style of the 20th century. The discovery of tetraethyl lead was "a beautiful [piece] of pure, or at least deliberately planned, research" and a systematic approach to a key problem (or "reverse salient") in the broad front of technological progress, Hughes said. Kettering and Midgley "tried out all elements possible in a so-called Edisonian style," Hughes said. The discovery of Ethyl was closer to the heart of generic questions about invention than most other stories about other discoveries, that have often been "simplistic and adulatory." 4

Other business and technology historians who mention the discovery include David Hounshell and John Smith, who discussed the development of Ethyl as one of many projects exemplary of du Pont's research and development strategy; and Joseph A. Pratt , who saw the public controversy over tetraethyl lead as the "Three Mile Island" of the 1920s. 5 A corporate history of Ethyl dealt with the discovery of tetraethyl lead as a succession of false starts, lucky incidents and scientific inspirations which led to the sole solution to the knock problem.6 And a 1961 history of the oil industry briefly surveyed the controversy and gave inaccurate numbers of dead and injured workers.7

The discovery of tetraethyl lead is a prominent part of several biographies of Charles Kettering. Most recent is Stuart Leslie's 1983 biography, Boss Kettering. The story of persistent investigation into anti-knock additives, somewhat in the style of Thomas Edison, is the theme of one chapter. Leslie noted that ethyl alcohol was briefly considered as an anti-knock but dismissed as a "will o' the wisp."8 Earlier biographies of Kettering were Thomas A. Boyd's 1957 Professional Amateur, and Rosamond Young's 1961 biography, Boss Ket .9 They paint sympathetic portraits ofCharles Kettering as a jocular and inspiring boss who was able to push a sometimes discouraged research team to new levels of achievement and develop the solution to the knock problem. Alternatives were not mentioned.

A scattering of public relations articles and a few references in scientific papers may be also found concerning the discovery of the anti-knock effect of tetraethyl lead. Also, a history of the development of anti-knock fuels for aviation on both sides of the Atlantic was printed. This book notes that the military need for high quality aviation fuels often drove other fuel research, such as the early anti-knock work by Kettering's Dayton Metal Products Co. 10

All of these works suffer from a serious handicap in that the public archives contain little of the detailed documentation historians might expect concerning a discovery of the magnitude of tetraethyl lead. Historians writing about Thomas Edison's 1879 invention of the electric light or Lavoisier's 1775 discovery of the oxygen principle have access to hundreds of day-to-day laboratory notebooks and thousands of records about their subjects.11 Yet Kettering and Midgley's lab notebooks are not available in any archive. Also missing are thousands of orignal documents which the research staff called the "Lead Diary." Board of Directors minutes for the Ethyl Gasoline Corp. are not available. Reports about the "high percentage" research, about tetraethyl lead production, and about worker health are all missing. With the exception of the Midgley unclassified documents at GMI, the public archives primarily contain memoirs and distillations of original documents rather than the original documents themselves. 12

Thus, tetraethyl lead, which was one technological solution to the knock problem, has been heavily documented through secondary sources, while other routes, which may have seemed equally viable in the early 1920s, and which were only discarded long after the inventive process was over, have not been documented at all. The "low percentage" research which led the research team to tetraethyl lead was not Kettering's only line of anti-knock fuel research, nor was it always the most important.


Anti-knock fuel research by Charles F. Kettering and his chief fuel researcher Thomas A. Midgley involved what Kettering called both high and low percentage additives. A low percentage additive might be a few grams per gallon of iodine, aniline, tetraethyl tin, tetraethyl lead or iron carbonyl. A high percentage additive might be ten to fifty percent by volume amount of benzene, toluene or alcohol in gasoline.

Kettering and Midgley's research moved through four phases in the period between 1916 and 1926:

1) an exploratory phase establishing methodology and involving primarily the Delco home lighting generator and aviation fuels;
2) a post-war phase focusing on automotive fuels and both high and low percentage anti-knock additives;
3) a systematic phase focusing on low-percentage additives with the option for high percentage additives retained; and
4) a consolidation phase around the low percentage additive involving bitter internal corporate disputes about alternative anti-knock additives and pitched public battles about the health impacts of leaded gasoline.

In the beginning, no one knew what caused engine knock. During the years before World War I, many people erroneously blamed Kettering's electric starter motor for the knocking and pinging in their car engines. As he travelled throughout the Midwest, demonstrating the electric starter to skeptical automakers, Kettering frequently thought about engine knock and how to silence it -- and his critics.

The problem went on the back burner for several years. One day in 1916, a young mechanical engineer fresh from Cornell University had finished another project.

"What do you want me to do next, boss?" Thomas Midgley is said to have asked. The conversation was the beginning of a seven year trail of research that would lead to the discovery of leaded gasoline and the investigation of dozens of other anti-knock compounds. Midgley continued working on knock even as Kettering sold Dayton Engineering Laboratories Co. (Delco) in 1916 and formed a new company, Dayton Metal Products Co. Research Division. The new company would play with research, Kettering said, in much the same spirit as a person plays golf - and with typical humor, he added, "but I don't think we used the same proportion of profanity."13

An early success put Kettering and Midgley firmly on the track of an anti-knock additive. In December 1916, Kettering wondered whether knock was related to the absorption of heat. He remembered a small red flower called the trailing arbutus that sometimes bloomed in the snow in Ohio. Perhaps it could absorb more heat because of its red color, he thought. This line of reasoning was completely off base, but it shows how little was known about fuel chemistry at the time. As the story goes, no dyes were available that day, but a company chemist did locate a bottle of iodine. A few drops in the carburetor of the test engine noticeably decreased the knock. Later, when some red dye was located, it proved to have no effect at all. The arbutus story is often recounted because it demonstrates that luck favors the prepared researcher who can isolate the essential fact and discard encumbering theory.14

World War I shifted Midgley's early fuel research to aircraft fuel at the Army Air Corp's airfield in Dayton. Midgley found that some types of fuels could be used in high compression engines while others would knock violently. On the list of antiknock fuels, pure ethyl alcohol was most effective, followed by aromatic petroleum compounds (benzene, toluene, xylene), then petroleum olefins, parrafins and ethers. Kettering and Midgley rejected some choices as unsuitable for aircraft. Benzene, for example, froze at 40 degrees F above zero, while temperatures aloft could go as low as 76 F below zero. Olefins were eliminated because they tended to form gum after a few months in storage. Ethyl alcohol was eliminated because of its lower BTU value, which meant that an airplane might have to take about one third again as much fuel to accomplish the same mission.

However, problems with the three alternatives could be overcome. Benzene could be made into cyclo-hexane, which had a very low freezing point. Olefin cracked gasolines could be used quickly or treated before use to remove gum. Alcohols could be mixed with benzene or gasoline to give an antiknock and anti-freeze effect without adding too much fuel weight.15

Kettering and Midgley settled on two fuels: they patented a mixture of 50 percent benzene and 50 percent gasoline,16 and prepared to go into production with a blend of cyclo-hexane and benzene called "Hecter" fuel.17

The 1918 Armistice put an end to the Hecter plan, but Kettering and Midgley had taken fuel research to a new plateau. "Engineers have heretofore believed knocking to be the unavoidable result of too high a compression, and while the fact that [ethyl] alcohol did not knock at extremely high compressions was well known, it was [erroneously] attributed to its extremely high ignition point ..."18

Instead, Midgley and Kettering said they believed that the effect involved the chemical structure of the fuel. Thus, high BTU fuels such as gasoline could, theoretically, run in high compression engines just as well as alcohol or benzene if some additive could be found to reduce knock. Lower BTU fuels such as alcohol would then not be needed for aviation.



Shortly after the war ended, G.M. founder William C. Durant reached an agreement with Kettering to turn Dayton Metal Products into G.M.'s Research Division. The merger was formalized early in 1919, and Kettering was made G.M.'s vice president of research. About the same time, in an effort to make the new acquisition appear efficient to the new management, Midgley was given two weeks to discover something to stiffen G.M.'s resolve to fund fuel research.

"Mr. Midgley has tenaciously adhered to the opinion that it was possible to secure a so-called 'pill' to overcome motor knock," said F.O. Clements, the lab's manager, defending Midgley. And yet,he observed, "the balance of the organization has given him very little encouragement." 19

According to T.A. Boyd, a research chemist working with Midgley who later documented some of the laboratory's work, Midgley's main research goal in the 1919-1920 era was to make an anti-knock fuel by using sulfuric acid to turn olefins into alcohols. "But in view of the verdict setting a time limit on how much further the research for an antiknock compound might continue, work was resumed at once in making engine tests of whatever further compounds happened to be available on the shelf of the lab... or which could be gotten readily," Boyd said. Midgley lost no time trying everything he could find in his one-cylinder laboratory test engine.

On January 30, 1919, with his deadline looming, Midgley tried a few drops of aniline in his test engine and dramatically reduced the incessant knock. This haphazard initial approach was hardly the epitome of the systematic, scientific research which would come later.

Meanwhile, Kettering had been advocating combined oil and auto industry research into the problem of developing better fuels and better engines. He made initial contacts with du Pont Corp. and Standard Oil of N.J. engineers and encouraged them to exchange research with G.M. engineers. He shared testing equipment and most of what his labs had learned - to the chagrin of the G.M. management and patent offices.

Altruistic motives aside, Kettering knew that G.M. would need partners to help market its anti-knock discoveries. The overtures were well received at Standard Oil. Following a meeting with Kettering, Chicago patent attorney F.A. Howard wrote to Standard chairman E.M. Clark: "Unless the fuel producers themselves get into this work of investigating the properties of their fuels, there is a good chance that they may have to pay tribute to others,"Howard said. "There would be such an insistent demand for (antiknock fuel) that any oil producer who had exclusive rights could absolutely dominate the entire motor fuel market."20



Oil industries may have worried about the dominance of the motor fuel market, but the possibility of a lack of oil has been a factor in the automotive industry's strategic planning.

As early as 1906, for example, representatives from the Detroit Board of Commerce supported legislation to free alcohol for fuel from beverage taxes. They told a U.S. Senate hearing that auto manufacturers worried "not so much [about] cost as ... supply" of fuel. 21

Similar fears of oil shortages have occurred in other periods during the 20th century. At the end of World War I, when demand for fuel skyrocketed and quality of fuel declined, geologists estimated that only 20 or 30 years worth of oil were left in the U.S. and a "gasoline famine" was possible. 22

Automotive engineers worried about "a calamity, seriously disorganizing an indispensable system of transportation." Aside from finding ways to import more foreign oil, one response was a search for an engine that was more tolerant of low-grade fuels. This would mean lower compression ratio engines that were less fuel efficient.

According to a 1919 article in Scientific American, the automotive industry could not ignore the country's declining oil reserves. "The burden falls upon the engine," the editors said. "It must adapt itself to less volatile fuel, and it must be made to burn the fuel with less waste....Automotive engineers must turn their thoughts away from questions of speed and weight... and comfort and endurance" and focus on averting the calamity.23

Kettering, then president of the Society of Automotive Engineers, maintained that despite fears of an oil shortage, engineers should refuse to compromise the design of the engine. In a 1919 SAE address, he insisted that the route to conservation of oil was through better quality fuel to be used in more efficient engines. This must have seemed a little contradictory, since declining fuel quality went hand in hand with the looming oil shortage. As high quality reserves played out, the lower quality petroleum fields were being used. Yet Kettering urged SAE members to take a longer view. He argued that low quality fuels would also run out and low compression engines would use them up even faster.

If, on the other hand, the fuel could be improved, engines could be developed with higher compression ratios, which would give better mileage, which in turn would extend fuel supplies.24

As noted briefly above, two types of additives could improve the anti-knock quality of gasoline, Kettering said: the "high percentage" and the "low percentage" additives. He cited forty percent benzene as an example of a high percentage additive which "makes an engine operate entirely satisfactorily," Kettering said. The low percentage solution was represented in 1919 by the accidental discovery that one percent iodine solution in gasoline could cut engine knock. It was too expensive and corrosive, Kettering said, but it pointed the way to a possible low percentage solution.

Yet assuming oil supplies were to be conserved with better engines, what would happen when oil finally ran out, as geologists then feared it would? In 1919, as General Motors integrated Kettering's research labs with the Detroit headquarters, one of the top priorities was to fortify the company against depletion or high cost of gasoline supply. The high compression motors that would come into general use if Kettering could overcome knocking, could more advantageously be switched to an alternative fuel -- most likely ethyl alcohol.25

Kettering and Midgley experimented with a variety of fuels, and patented many blends, as we shall see. However, they found the most interesting high percentage anti-knock additive to be ethyl alcohol (ethanol). Alcohol had been used a fuel before petroleum26 and at the time was well known in the U.S. and Europe.

The U.S. history of alcohol fuels has been well explored in the 1930s period byGiebelhaus,27 Bernton28 and Kovarik,29 but the early his-tory of alcohol as a fuel has not. In the years between the development of the automobile and World War I, a lively competition with races and expositions took place between electric, steam and internal combustion engines as well as various kinds of liquid fuels. An exhibit of alcohol fueled vehicles and appliances filled the Paris exhibition hall in 1902, and alcohol fuel was common in Europe -- and especially France and Germany -- before, during and after World War I. In 1918, Scientific American cited war research in France and England and concluded: "It is now definitely established that alcohol can be blended with gasoline to produce a suitable motor fuel."30

Harold B. Dixon of the British Fuel Research Board summed up his group's conclusions that alcohol's greater useful compression ratio compensated for its lower BTU value. A mixture of alcohol with 20 per-cent benzene orgasoline "runs very smoothly, and without knocking," he said in a 1920 Society of Automotive Engineers Journal article.31 The consensus, Scientific American said, was "a universal assumption that [ethyl] alcohol in some form will be a constituent of the motor fuel of the future." Alcohol met all possible technical objections, and although it wasmore expensive than gasoline, it was not prohibitively expensive in blends with gasoline. "Every chemist knows [alcohol and gasoline] will mix, and every engineer knows [they] will drive an internal combustion engine," Scientific American said.

The prevailing view in 1920, then, was that high percentage class additions to fuels would be necessary if higher compression ratios were to be achieved, or, alternatively, engines that were more tolerant to low grade fuels would be needed to run on gasoline.32

As iodine and other compounds proved too expensive and complex to produce, Midgley and Kettering's investigation of a pill or low percentage class additive to combat fuel knock had come to a stalemate. The impasse was the "dark hour before a break in the clouds," T.A. Boyd later said. Midgley was depressed and wanted to drop the entire investigation.33

In October, 1920, Midgley filed a patent application on an aniline anti-knock additive injector for engines,34 but he did not think it would succeed. "I doubt if humanity, even to doubling of fuel economy, will put up with this smell," Midgley wrote C.M. Stine of du Pont. Stine had been asked to develop plans for a full scale production effort for aniline. Kettering conceded that du Pont was "out of sympathy with our point of view," and that they would have to do something "to stimulate interest in what is today the only known solution to the problem."35

Although Kettering may have meant the only known low percentage solution to the problem, along with the other options, his tone indicated support for Midgley's approach.

In the spring of 1921, Kettering chanced across a newspaper article on selenium and asked Midgley to try it. On April 6, just as the low percentage anti-knock project was about to be abandoned, Midgley discovered that selenium and tellerium had antiknock effects greater than aniline, although they smelled even worse. G.M. expanded the low percentage research effort and shifted it to a more systematic scientific approach. Guided by a partial periodic table of elements designed by Robert Wilson of the Massachusetts Institute of Technology, Midgley began focusing on groups of elements with potential antiknock effect.

He pasted a chart of 20 elements in four groups onto a peg board and mapped the antiknock values of each element as it was tested. By August, 1921, preliminary tests pointed to lead as the best low percentage antiknock additive. The use of the periodic table marked a shift of research styles that historians have seen as a turn from raw empiricism to a reasoned scientific method.

Still, it is interesting that German chemist Carl Bosch felt that his researchers would have rebelled at a Kettering's peg-board method, so crudely rooted in the empirical tradition. When Kettering visited Bosch's laboratory in 1924, he smiled at the "cut and try" empiricism: "That might work in America, but I could never get my fellows to do it that way, Bosch said." 36


As work continued on analine and other low percentage compounds in 1920 and 1921, the idea of what was needed in fuel research continued to evolve. Midgley and T.A. Boyd consulted with experts in the U.S. Bureau of Mines who said that the idea of improving low grade fuels seemed less urgent than the long range petroleum supply problem.

Around 1920 and 1921, Kettering and his British counterpart H.R. Ricardo had began to believe that alcohol fuel from renewable resources would be the answer to the long term supply problem. "At almost the same time, both researchers [Kettering and Ricardo] settled on alcohol as the key to unshackling the internal combustion engine from non-renewable fossil fuels," said historian Stuart Leslie. "Ethanol (ethyl alcohol) never knocked, it could be produced by distiling waste vegetable material, and it was almost pollution-free." Ricardo compared renewable alcohol fuel to living within one's means, implying that fossilfuels were "a foolish squandering of capital."37

Despite Ricardo and Kettering's optimism over the advantages of alcohol fuel, staff researchers had previously concluded that farm crops would not satisfy the enormous fuel need if a total substitute for petroleum had to be found. A 1919 du Pont study found that a nationwide switch to ethyl alcohol would take 50 to 60 percent of the entire grain and sugar crop.38 Similarly, Boyd reported that some 46 percent of all foodstuffs would have to be converted to alcohol to replace gasoline on a BTU for BTU basis.39

In April of 1921, Boyd again surveyed the steep rise in number of new cars and the increasing depletion of oil reserves. The solution, Boyd said, would be to use other fuels, and benzene and alcohol "appear to be very promising allies" to petroleum. Alcohol was the "most direct route ... for converting energy from its source, the sun, into a material that is suitable for a fuel..." Boyd said. But again, Boyd noted supply problems. In 1921, about 100 million gallons of industrial alcohol was being distilled. There was enough corn, sugar cane and other crops begin grown to produce almost twice the demand for gasoline, which was about 8.3 billion gallons per year.

Yet Boyd resisted the idea of fueling the nation with food crops, saying it "seems very unlikely." Large-scale production of benzene was also questionable. Even if all the coal mined in the U.S. in 1920 were used to supply benzene, only about 900 million gallons, or one-fifth of the U.S. gasoline supply would be replaced, he said. 40

Kettering, in a speech around 1921, noted that "industrial alcohol can be obtained from vegetable products ... [but] the present total production of industrial alcohol amounts to less than four percent of the fuel demands, and were it to take the place of gasoline, over half of the total farm area of the United States would be needed to grow the vegetable matter from which to produce this alcohol."41

By framing the question only in terms of total replacement of fuel, Kettering, Boyd and the du Pont engineers were probably not ignoring the high percentage solution, a 20 or 30 percent blend with gasoline, but rather using a worst case scenario of rapid and total oil depletion. At this stage of their research, they did not appear to be politically or technically opposed to the use of ethyl alcohol blends in gasoline. Kettering spoke out against taxes on alcohol as an impediment to fuel research and helped overcome other obstacles. For example, in 1920, G.M.'s head of overseas marketing wrote Kettering to note that the alcohol fuel use "is getting more serious every day in connection with export cars, and anything we can do toward building our carburetors so they can be easily adapted to alcohol will be appreciated by all."

Kettering assured him that the adaptation "is a thing which is very readily taken care of," and said that G.M. could rapidly change the floats in carburetors from lacquered cork to metal, which it did shortly thereafter.42

Midgley also filed a patent application for a blend of alcohol and cracked (olefin) gasoline on February 28, 1920, clearly intending it to be an antiknock fuel.43

The problem of the long-term resource base for the fuel of the future continued to worry Kettering and Midgley. At one point they became interested in work on cellulose hydrolysis being performed by Harold Hibbert at Yale University. Hibbert pointed out that the 1920 U.S.G.S. oil reserve report had serious implications for his work. "Does the average citizen understand what this means?" he asked. "In from 10 to 20 years this country will be dependent entirely upon outside sources for a supply of liquid fuels... paying out vast sums yearly in order to obtain supplies of crude oil from Mexico, Russia and Persia." But the chemist might be able to solve the problem, Hibbert said, by working on abundant cellulose waste from farm crops, timber operations and sea-weed as a source of ethyl alcohol.44

In the summer of 1920, Boyd and his family moved to New Haven so that he could study with Hibbert. Boyd found Hibbert impressive but he admitted that he was overwhelmed by the volume of literature about cellulose hydrolysis. When Midgley came east in late July, he was more interested in meeting Standard Oil Co. officials than with Hibbert, and Boyd left without a clear sense of how quickly cellulose research could produce commercial results.

Boyd realized that a source of alcohol "in addition to foodstuffs" must be found, and that the source would undoubtedly be cellulose: "It is readily available, it is easily produced and its supply is renewable." Using it and returning farm crop residues to the soil would not harm soil fertility. But the problem of developing a commercial process for cellulose conversion to alcohol was serious, he had learned in his stay with Hibbert. At the time, a ton of wood yielded only 20 gallons of alcohol in the least expensive weak acid process, whereas a commercially profitable weak acid process would need a yield of at least 50 gallons, and possibly 60 to 65, Boyd said. Such yields had been achieved with the strong acid process, but that technology was complex and more expensive. Still, success might be found if the strong acid yield could be obtained in a weak acid process, and as a result, "the danger of a serious shortage of motor fuel would disap- pear," Boyd said. "The great necessity for and the possibilities of such a process justify a large amount of further research."45

To promote this research direction among other engineers, Midgley drove a high compression ratio car (7:1) from Dayton to an October, 1921 Society of Automotive Engineers meeting in Indianapolis using a 30 percent alcohol blend in gasoline. "Alcohol has tremendous advantages and minor disadvantages," Midgley told fellow SAE members in a discussion. Advantages included "clean burning and freedom from any carbon de- posit... [and] tremendously high compression under which alcohol will operate without knocking... Because of the possible high compression, the available horsepower is much greater with alcohol than with gasoline..."

Minor disadvantages included low volatility, difficulty starting, and difficulty in blending with gasoline "unless a binder is used."

Another unnamed engineer (probably from G.M., possibly Boyd) noted that a seven and a half percent increase in power was found with the alcohol-gasoline blend "... without producing any 'pink' [knock] in the engine. We have recommended the addition of 10 percent of benzol [benzene] to our customers who have export trade that uses this type of fuel to facilitate the mixing of the alcohol and gasoline."46 Midgley also mentioned the cellulose project. "From our cellulose waste products on the farm such as straw, corn- stalks, corn cobs and all similar sorts of material we throw away, we can get, by present known methods, enough alcohol to run our automotive equipment in the United States," he said. The catch was that it would cost $2 per gallon. However, other alternatives looked even more problematic - oil shale would be too expensive, and coal could only deliver about 20 percent of the total fuel need. 47

Fellow engineers were clearly interested in Midgley's viewpoint, but there was a another catch - Prohibition of alcoholic beverages. Not only was it increasingly difficult to envision a network of industrial alcohol facilities, given the problem of avoiding illegal diversion of the fuel, but Prohibition had also made it difficult even to experiment with alcohol fuel. A tone of frustration is evident in a memo from F.O. Clements, lab manager in Dayton, to the staff dated September 9, 1921. "We have finally managed to secure some 96 percent grain alcohol and a small amount of absolute alcohol..." With the laws against alcohol consumption, such a rare cache demanded vigilance, and the rest of the lengthy memo detailed complex security, requisition and reporting procedures.48 In contrast, European engineers around this time were not only un- restricted but positively encouraged to help develop alcohol fuel industries for security reasons by governments of countries without domestic oil reserves.


In the summer and fall of 1921, Kettering, Midgley and the G.M. research team began a series of tests that would change the automotive world. The peg board with 20 elements pasted on it guided the Dayton researchers through tests of al-ready known knock suppressors (such as bromine, iodine, tellurium, tin and selenium) and novel elements for fuel tests (arsenic and sulfur).

The atmosphere in the labs grew more expectant as the pegboard seemed to point the way toward the heavy end of the carbon group: silicon, germanium, tin and lead.

Visiting his father in Massachusetts in late October, Midgley had antiknock results from each new test sent via telegraph daily. Tetraethyl tin proved effective, but even more exciting was the prospect of metallic lead at the bottom of the column on the peg board.

By this time, Midgley's "scientific foxhunt" of seven years had involved tests of hundreds or possibly thousands of compounds, although there is little agreement on the numbers. 49

When the chemists finally delivered a small amount of tetraethyl lead on the morning of December 9, 1921, the knock in the one-cylinder laboratory engine was utterly silenced. Even diluted to a strength of two or three grams per gallon, or one thousand to one, tetraethyl lead had a remarkable ability to quiet the relentless knocking. Midgley, Boyd and others in thelab "danced a very un-scientific jig" and hurried off to include Kettering in their victory party. Holding a test tube full of the stuff in his fingers, Kettering suggested, perhaps ironically, the name "ethyl" for the chemical compound tetraethyl lead. Although the term referred to the ethyl alcohol solvent used to dissolve the lead, and utterly confused the question of high percentage versus low percentage solutions, the name Ethyl stuck.50

While Dayton danced, Detroit yawned. Kettering's boss, G.M. president Alfred P. Sloan, was not enthusiastic about tetraethyl lead. An attorney for G.M. later recalled Sloan's attitude: "When Kettering found that the element iodine would do it, he [Kettering] said, this is the answer. And when he had aniline, he said, this is the answer. And when he had selenium, he said this is the answer... And so, when tetraethyl lead was discovered, Sloan thought: 'it won't be long before we get something better than this.'"51

Perhaps in order to show Detroit how interested people were, the Dayton labs announced in February 1922 that a new gasoline additive could double mileage. Tetraethyl lead was still secret at the time, and the Associated Press story read: "Discovery of a tellurium gasoline compound which increases gasoline mileage by one hundred percent over present gasoline fuel was announced at the research lab of the G.M. Co. here today." Several hundred enthusiastic letters, mostly from small companies with delivery services, landed on Midgley's desk. He answered them with a standard response:

"The newspaper article, like most newspaper articles, does not give the whole story. We do have compounds that influence the rate of combustion of gasoline in an internal combustion engine; the savings to be effected have to do with doubling the compression of the motor. With the ordinary low compression motor we can do nothing, save to completely eliminate the knock."52


Midgley and Kettering's interest in ethyl alcohol as a high percentage anti-knock fuel did not fade once tetraethyl lead was discovered. It was still considered to be the fuel that would eventually replace petroleum. This is seen in a May, 1922 memo from Midgley to Kettering that evaluated a report on alcohol production from the century plant of the Mexican desert. Midgley said he was "not impressed" with the process as a way to make motor fuel:

"Unquestionably alcohol is the fuel of the future and is playing its part in tropical countries situated similar [sic] to Mexico. Alcohol can be produced in those countries for approximately 7 - 1/2 cents per gallon from many other sources than the century plant, and the quantities which are suggested as possibilities in this report are insignificantly small compared to motor fuel requirements. However, as a distillery for beverage purposes, these gentlemen may have a money making proposition." 53

Even as chemists tinkered with various processes to produce tetraethyl lead in a nearby lab, Midgley and Boyd continued working on alcohol for fuel. In a June 1922 SAE paper, they said:

"That the addition of benzene and other aromatic hydrocarbons to paraffin base gasoline greatly reduces the tendency of these fuels to detonate [knock] ... has been known for some time. Also, it is well known that alcohol ... improves the com bustion characteristics of the fuel ... The scarcity and high cost of gasoline in countries where sugar is produced and the= abundance of raw materials for making alcohol there has resulted in a rather extensive use of alcohol for motor fuel. As the reserves of petroleum in this country become more and more depleted, the use of benzene and particularly of alcohol in commercial motor fuels will probably become greatly extended." (Italics indicate oral presentation only)."54

G.M.officials encouraged Midgley to keep looking into alcohol fuel after the discovery of tetraethyl lead. In correspondence with the company's patent attorneys, for example, the question of a patent issued to Industrial Alcohol Co. for a combination of petroleum and an "ester" (made from ethyl alcohol) for antiknock effects had come up in the summer of 1922. Midgley was encouraged to experiment with the idea. "Try it out and see if the U.S. Industrial Alcohol Co. have opened up a valuable line of research," said J.W. Morrison in the G.M. Patent Dept. "Mr. Clements [the Dayton lab manager] stated some time ago that it might be worth our while to carry our investigations further on the problem of utilizing alcohols in motors. I think he mentioned more specifically combinations of alcohol and gasoline."55

In September, 1922, Midgley and Boyd wrote a paper asserting that "vegetation offers a source of tremendous quantities of liquid fuel." Cellulose from vegetation would be the primary resource because not enough agricultural grains and other foods were available for conversion into fuel. "Some means must be provided to bridge the threatened gap between petroleum and the commercial production of large quantities of liquid fuels from other sources. The best way to accomplish this is to increase the efficiency with which the energy of gasoline is used and thereby obtain more automotive miles per gallon of fuel." 56

At the time the paper was written, in late spring or early summer 1922, tetraethyl lead was still a secret within the company. It was about to be announced to fellow scientists and test marketed. The reference to a means to "bridge the threatened gap" and increase in the efficiency of gasoline clearly implies the use of tetraethyl lead or some other low percentage additive to pave the way for new fuel sources. This inference is consistent with N.P. Wescott's 1936 legal history of Ethyl Gasoline for the du Pont corporation, which stated:

"It is also of interest to recall that an important special motive for this [tetraethyl lead] research was General Motors' desire to fortify itself against the exhaustion or prohibitive cost of the gasoline supply, which was then believed to be impending in about twenty-five years; the thought being that the high compression motors which should be that time have been brought into general use if knocking could be overcome could more advantageously be switched to alcohol. "57

Clearly, this du Pont observation squares with Kettering and Midgley's research direc- tion. Ethyl leaded gasoline, the low percentage solution, would serve as a transition from the past to the "fuel of the future" that would keep America's cars on the roads no matter what calamity might befall the oil industry.


For years after tetraethyl lead was discovered, alcohol and benzene blends were considered much more reliable antiknock agents. Navy tests in 1923 provided "very satisfactory results," with a 30 percent alcohol blend in gasoline that would "soon take the place of gasoline altogether."58 A Naval Advisory Committee report said in 1925 noted the anti-knock value of alcohol / gasoline blends. It cautioned that alcohol might "reduce the amount of food products and its economic soundness is open to question," but also noted that alcohol from vegetation was a renewable resource and in an emergency could be produced in unlimited quantities. 59

Midgley also trusted alcohol / benzene blends more than tetraethyl lead. He confidentially advised U.S. Navy fliers attempting a cross-Pacific flight not to use Ethyl leaded gasoline (which had only begun to be marketed).

"We have made great progress in overcoming the spark plug and valve trouble caused by (Ethyl lead) ... but we have not yet solved the problem to our entire satisfaction; and, in view of the fact that it is essential that no engine trouble of any kind develop, it seems wise not to risk the use of this material ... Probably the best possibilities are offered by a fuel consisting of a gasoline-benzol-alcohol blend..."60

Troubles continued to test Kettering and Midgley's commitment to tetraethyl lead in the 1922 to 1923 period. The compound was extremely hard to make and it broke down quickly in the sunlight. Engine tests showed that particles of lead burned holes in the exhaust system and valve seats. Lead oxide also caked onto spark plugs, stopping the engine after a few thousand miles. There was also the problem of how to physically deliver the dangerous additive to the gasoline market.

Midgley believed all these problems could be overcome. Tetraethyl lead would be kept in light-tight containers. Valve seats and exhaust pipes would be made with harder alloys.Reactive lead particles could be neutralized with an additional chemical agent, for exam- ple, an acid or a radical that could combine with lead, such as chlorine, sulphur, selenium or bromine. "We may hope at almost any time to find a sufficiently satisfactory solution to the problem so that initial marketing at least may be started," Midgley said.61

Midgley's originally delivery method was to sell a "pill" made of tetraethyl lead and a waxy substance (paratoluidune) that would dissolve in gasoline. A patent application in April, 1922 covered the basic concept, and a specific patent application was made in October, 1922.62 But "pills" to turn water into gasoline and other fraudulent schemes had made the public wary of such approaches, and the first product marketed in 1923 was con- centrated "Ethyl fluid" blended by pouring the concentrate by hand into the glass container at the service station pump.

When Midgley and Boyd presented a paper on their remarkable new anti-knock fluid in September, 1922, scientists inside and outside G.M. were enthusiastic. Sample batches were sent to du Pont, Standard Oil of N.J., Standard of Indiana, Sun Oil Co., the Bureau of Naval Aeronautics, and a variety of university researchers. Midgley's work was rewarded in December 1922 with the news that he had won the prestigious William H. Nichols Medal from the New York section of the American Chemical Society (ACS). Wilson of MIT wrote that it was "just the beginning" of the recognition that Midgley would receive for his work. In fact, Midgley would receive three more honorary ACS medals in 1937, 1941 and 1942 before he died in 1943.

However, it was the Nichols medal that "had extraordinary importance," said Boyd, "... for the effect it had a few years afterwards when the addition of tetraethyl lead to gasoline was under attack by those who claimed that it would poison the whole nation. When that time came, those in technological circles, having been informedabout the development and sympathetic to it, demanded and got a factual rather than hysterical consideration of the case."63


When Thomas Midgley accepted the Nichols Medal in March, 1923, he had almost returned to normal after fighting a winter-long battle with lead poisoning. He and three other lab employees had experienced "digestive derangements, subnormal body temperatures and reduced blood pressure" from handling tetraethyl lead.64 Midgley was exposed routinely but had also been caught in at least two laboratory explosions. In July, 1922, when Kettering and Midgley gave a demonstration of tetraethyl lead production to visiting du Pont engineers, the process "got entirely out of hand, and spewed all over the place, and we had to get out," said Willis F. Harrington of du Pont. On another occasion in 1922, Midgley lost control of the process and fragments of lead embedded in his eyes.

According to a note to his doctor, he used mercury as an eyewash to dissolve it.65 Midgley wrote openly about the problem. He declined speaking offers at three ACS regional panels in January, 1923 by noting:

"After about a year's work in organic lead I find that my lungs have been affected and that it is necessary to drop all work and get a large supply of fresh air."66

Throughout 1922, as the first plans were made to develop tetraethyl lead, Midgley had received alarming letters from four of the world's leading experts in the field: Wilson of MIT, Reid Hunt of Harvard, Yandell Henderson of Yale and Charles Kraus of Pottsdam in Germany. Kraus had worked on tetraethyl lead for many years and called it "a creeping and malicious poison" that had killed a senior scientist at his university. Hunt had informed Henderson about the work at G.M. because the Yale researcher was considered America's leading expert on automotive exhaust.67

Another warning came from a lab director in the Public Health Service (P.H.S.), who had heard about tetraethyl lead and wrote an October, 1922 memo to the assistant surgeon general warning of a "serious menace to public health." Several other memos traded hands and in November, Surgeon General Hugh Cumming wrote to Pierre S. du Pont about the public health question. The Surgeon General's letter was referred to Thomas Midgley, who responded on December 30, 1922 that the problem "has been given very serious consideration .. although no actual experimental data has been taken."68

Despite his own condition, Midgley was nonchalant about the dangers of tetraethyl lead. In a December 2, 1922 letter to A.W. Browne at Cornell, who had been contracted for some analytical work, Midgley said that tetraethyl lead was irritating to the skin and should not be breathed or taken in the mouth.

He added: "It would not surprise me if in the course of using tetraethyl lead for a year that some of your men would experience a slight case of painter's colic. This is nothing to worry about as several of our boys have it."69

While in Miami recovering from lead poisoning, Midgley also wrote to an oil industry engineer that poisoning of the public was "almost impossible, as no one will repeatedly get their hands covered in gasoline containing tetraethyl lead - it stings and burns... The exhaust does not contain enough lead to worry about, but no one knows what legislation might come into existence fostered by competition and fanatical health cranks."70

Apparently unconvinced by Midgley's December 30, 1922 response to their inquiry, the P.H.S. decided that an investigation was necessary and contacted the Bureau of Mines. Midgley and Kettering were familiar with the Bureau of Mines petroleum experts based in Pittsburgh, Pennsylvania, and had also asked them to perform a health study of Ethyl gasoline around the same time. Bureau employees felt that the agency was in an uncomfortable position. In June, 1923, A.C. Fieldner, a bureau chemist, said that an investigation would be inadvisable: "The relations of the Bureau of Mines with some of the gasoline interests or motor interests will be imperiled regardless of our decision in the matter. The results promise to be so doubtful, the investigation will take so much time and cost so much money and chances for getting into trouble with some commercial interests are so great that I believe it is inadvisable to take on this investigation."

Yet in September, 1923, an agreement was finalized between G.M. Research Corp. and the Bureau of Mines in Pittsburgh. The bureau agreed to Kettering's demand that it "refrain from giving out the usual press and progress reports during the course of the work, as [Kettering] feels that the newspapers are apt to give scare head- lines and false impressions before we definitely know what the influence of the material will be."

Kettering and the bureau were so worried about the press that all official correspondence used the trade name Ethyl rather than the word "lead" to avoid leaks to the newspapers, "as this term is apt to prejudice somewhat against its use," according to the superintendent of the Pittsburgh field station. The contract also specified that manuscripts of all reports were to be submitted to G.M. "for comment, criticism and approval."71

The actual tests began in the fall of 1923 with a small Delco motor provided by G.M.. Various animals were exposed to Ethyl gasoline exhaust from the motor. One dog exposed to the fumes gave birth to five puppies in the test chamber "without harm of any kind," Boyd later wrote. The dogs were called the "Ethyl Gas Hounds."72

Meanwhile, on June 23, 1924, G.M. president Alfred Sloan, "gravely concerned about the poison hazard," and reeling from two tetraethyl lead deaths in Dayton and one in Deepwater, approved the formation of a medical committee with W.G. Thompson of Cornell University, a consulting physician to Standard Oil, as chairman. A few days later, Irenee du Pont wrote to Sloan saying that the development of tetraethyl lead "may be killed by a better substitute or because of its poisonous character or because of its action on the engine."73

The medical committee issued a report described as negative and highly cautionary on August 20, 1924 and Irenee du Pont reassured Sloan: "I have read the doctors report and am not disturbed by the severity of the findings." Nitroglycerin was even more hazardous to make, and lead dust from car exhaust would be only a fraction of that from erosion of paint, he said.74

Thus, even as G.M. and Standard were about to form a partnership and greatly expand Ethyl's role in the gasoline market, its fate was still quite uncertain. What propelled these enormous corporations to take such risks? A note from Midgley to Kettering on March 2, 1923 shows that both were aware of the enormous potential profits in tetraethyl lead.

"The way I feel about the Ethyl Gas situation is about as follows: It looks as though we could count on a minimum of 20 percent of the gas sold in the country if we advertise and go after the business - this at three cent gross to us from each gallon sold. I think we ought to go after it as soon as we can without being too hasty... " 75

With gasoline sales around eight billion gallons per year, 20 percent would represent two billion gallons, and three cents gross would bring in $60 million per year. With the cost of production and distribution less than one cent per gallon of treated gasoline, more than two thirds of this would be annual gross profit. As it turned out, these original figures dancing through Midgley's mind were modest compared to the market success that would come later.


Three manufacturing efforts got under way in 1923 and 1924. The first was a small G.M. operation in Dayton, Ohio, which made 7 gallons of tetraethyl lead each day and shipped it out in one-liter bottles. Each liter would treat about 300 gallons of gasoline.

When the two workers on the assembly line packing the bottles died in April, 1924, the line was shut down. Kettering later blamed the lack of safety on the workers themselves.

"We could not get this across to the boys," he said. "We put watchmen in at the plant, and they used to snap the stuff [pure tetraethyl lead] at each other, and throw it at each other, and they were saying that they were sissies. They did not realize what they were working with."76

The second and by far the largest manufacturing operation was built at du Pont's dyestuffs division in Deepwater, N.J., across the bay from Wilmington, Delaware. Du Pont began with a 100 gallon per day "bromine" process unit in August of 1923, and increased production in the summer of 1924 to 700 gallons per day. A second 1,000 gallon per day unit using Standard's "chloride" process began operations in January, 1925. The first du Pont worker died in September, 1923; three more died over the summer and fall of 1924 when bromine unit production was stepped up; and four more died in the winter of 1925 in the new chloride unit. Workers who were aware of the effects of tetraethyl lead called the factory the "House of Butterflies" for the hallucinations they experienced.

The third and smallest manufacturing unit was a 100 gallon per day "semi-works" built in the summer of 1924 at the Standard Oil of N.J. refinery in Bayway, N.J. It began operations in September, 1924 and shut down in October after five workers died and 44 others were hospitalized.

In the months preceding this disaster, as G.M. and du Pont Corp. struggled to bring the new product on line, an internal controversy erupted over worker safety standards in manufacturing, the possibilities of alternatives. The controversy eventually ended the tenure of Kettering and Midgley as president and vice president of Ethyl Gasoline Corp.

When construction began on the large scale du Pont plant, in April of 1923, Irenee du Pont wrote du Pont's technical director, W.F. Harrington: "It is essential that we treat this undertaking like a war order so far as making speed and producing the output, not only in order to fulfill the terms of the contract as to time but because every day saved means one day advantage over possible competition..."77 The competition was not from other sources of tetraethyl lead but rather other types of antiknock additives and refining processes which were beginning to come into the market.

Despite the hurry, the du Pont plant's 1923 opening was delayed because "a considerable number of men had been more or less seriously affected" by lead poisoning during the trial runs of the new system. By September, 1923 the 100 gallon per day operation was in full production, although at least one worker was in the hospital and others had begun to complain of strange hallucinations of flying insects. Workers began calling the plant the "House of Butterflies."

On September 21, Frank W. Durr, a 37-year-old process operator who had worked for 25 years for du Pont, became the first of eight du Pont employees to die of lead poisoning. Du Pont took additional precautions and no other workers died of lead poisoning in Deepwater until the summer of 1924, when production was stepped up to meet new demands. Altogether, between 1923 and 1925, eight du Pont workers died.78

Demand for Ethyl fluid grew rapidly in 1923 and skyrocketed in January 1924 when G.M. signed exclusive contracts with Standard of New Jersey, Standard of Indiana, and Gulf Oil Co. to distribute the new antiknock fluid on the East Coast, the Midwest and the South, respectively. The contracts stipulated that adding three grams of Ethyl fluid per gallon would have the same antiknock effect as adding 40 percent benzene.79

Du Pont had continual problems meeting G.M.'s increasing demands for tetraethyl lead through its bromine-based process. In June 1924 Kettering complained that the "whole program is prejudiced" because du Pont was moving too slowly.80 Yet two G.M. workers died in the spring of 1924, and the Dayton staff was said to be "depressed to the point of giving up the whole tetraethyl lead program."81

Standard, meanwhile, had developed and patented a new kind of tetraethyl lead manufacturing process that employed ethyl chloride rather than bromine. G.M. chairman Sloan believed that competition would help hold du Pont back from potential price in- creases in the future and that the Standard patent position would force concessions from G.M. in any event. According to court testimony in later years, du Pont officials were unaware that G.M. was about to begin a joint venture with Standard that would create the company called the Ethyl Gasoline Corp. in August, 1924 with Kettering and Midgley as president and vice president. 82

Standard's chloride process was slightly cheaper than du Pont's original bromide process by about four cents per pound of pure tetraethyl lead. Diluted 1,200 times in gasoline, the retail level difference would be one-twentieth of a cent ($0.0005) per gallon of gasoline.

However, the chloride process involved higher temperatures and pressures, which made it far more dangerous than the bromine process that had already killed six or seven workers and poisoned hundreds of others. Du Pont engineers had serious reservations when G.M. decided to allow Standard Oil Co. to build a tetraethyl lead plant using the chloride process at their refinery in Bayway, New Jersey, as the du Pont internal history emphasizes.83

Because du Pont Corp. owned one third of G.M. stock and was a partner in everything G.M. did, Du Pont engineers felt they had a right to insist that manufacturing be kept in one place for safety's sake, especially considering the severe safety problems they already faced.

When du Pont's use of the new chloride process came up for consideration in the spring of 1924, a du Pont engineering committee insisted on approaching it with the idea of a closed system. Du Pont engineers wanted to keep the entire series of highly volatile chemical reactions closed off and isolated from workers from start to finish. Planning began in April, 1924 and construction began in September, 1924, but the du Pont ethyl chloride plant did not start operating until January, 1925. In contrast, Standard took less than three months to design, build and begin operating the Bayway, N.J. plant, beginning in June 1924.

As demand accelerated in the summer of 1924, du Pont stepped up the older bromide production line from around 200 gallons per day to 400 in June, then 500 in July, and then 700 by August. As a result, three more workers died with wild and violent hallucinations.

The internal controversy came to a head when a delegation of du Pont chemists led by W. F. Harrington visited Standard's Bayway plant in September, 1924. The contrast between the du Pont approach and the Standard approach was evident from the moment Harrington and his team walked through the door. They saw a large, open factory floor with three main work areas. In the first area, a large iron vessel shaped like two ice cream cones stuck top to top was rotating on its side. From within the vessel came the muffled sound of heavy explosions as sodium reacted violently with ethyl chloride and lead. As the double cone rotated, steel agitation balls churned through the boiling sodium to ensure proper mixing. When the reaction calmed down, a crane moved the double cone to the second work area, where workers unbolted the hatches over the narrow ends, releasing concentrated fumes from inside. They attached steam lines and condensers, and tetraethyl lead was distilled in much the same way that whiskey is distilled from a vat of beer.

When the distillation was over, workers opened the iron vessel once again and scraped the steaming, leftover lead mush through a grate in the floor with shovels, gloves and boots. As the mush went through the grate, workers recovered the steel balls that would be used to agitatethe next batch.

The du Pont engineers were "greatly shocked at the manifest danger of the equipment and methods [and] at inadequate safety precautions," but their warnings were "waved aside." 84

When Kettering and Midgley asked du Pont to adopt Standard's process in order to speed up production, Harrington refused. "I personally thought it was too dangerous a process for us to use," he said, and got permission in the summer of 1924 to proceed with a far safer design. The du Pont design used a closed system with ventilation for the workers. There was also a stationary reactor with permanent agitators, a contained transfer system to a distillation unit in the floor below, and finally a contained recovery system for the leftover sludge.85

Irenee du Pont felt that, had the company been given more time, the more dangerous ethyl chloride process could have been made even safer. "In due course the more dangerous trip [technical development] could have been made safe, but it was an expensive trip to have tried it more or less prematurely in the hands of novices," du Pont said.86 He believed that Standard (the "novices") had made a serious error of judgement. "Notwithstanding ... foreknowledge of the peril, the precautions taken in the small manufacturing operation at Bayway were grossly inadequate."87

Another reflection of the tone of the internal controversy was this statement by a General Motors attorney:

"They [Standard] put up a plant that lasted two months and killed five people and practically wiped out the rest of the plant. The disaster was so bad that the state of New Jersey entered the picture and issued an order that= Standard could never go back into the manu- facture of this material without the permission of the state of New Jersey. In fact, the furor over it was so great that the newspapers took it up, and they misrepresented it, and instead of realizing that the danger was in the manufacture, they got to thinking that the danger was exposure of the public in the use of it, and the criticism of its use was so great that it was banned in many cities and they had to close down the manufacture and sale of Ethyl.... "88



The lead poisoning deaths of the first workers in Dayton, Ohio and Deepwater, N.J. had not attracted attention. But when the first Standard Oil Co. worker died on October 22, 1924, the Union County, N.J. medical examiner called for an investigation into the mysterious gas that was driving workers crazy. Within a few hours, G.M.'s carefully contained secret had become front page news across the nation. To make matters worse, the chief chemist at the refinery told reporters: "These men probably went insane because they worked too hard."89

The following day, as another man died and some 40 more were hospitalized, Yandell Henderson told reporters that the mystery gas was "one of the most dangerous things in the country today," and was being produced without regard for public health.90

As four more workers died, Standard Oil Co. directors were "in a blue funk over the whole thing," Kettering said later. "The directors were very much afraid about it. They didn't know what was going to happen to them."91

Standard issued only short, guarded comments. Telegrams flew between Kettering, who was then in Paris, and Standard headquarters in New York. Meanwhile, New Jersey authorities banned leaded gasoline; then state legislatures in New York, Pennsylvania and others in New England condemned the new additive and forced gasoline dealers to take it off the market. The bright future for G.M. 's new invention lay in ruins. The effect was "disaster -- sudden, swift and complete," said du Pont's history of the incident.92

The New York Times said on October 31, 1924: "In all the history of chemistry, no case like this is recorded. Laboratory workers, of course, have been killed before now, but in each instance the number has been small, and usually they have died while experimenting with known explosives or seeking to find new ones. The Bayway disaster has many entirely novel features... For many days workers showed no signs of illness. The fumes evidently were cumulative in their effects ... (and) mental disturbance ... soon turned to outright mania with wild and violent delirium in the worst cases." 93

G.M. insisted that the Bureau of Mines now make public its report, and on October 31 the bureau issued a statement concluding that the danger of the public breathing lead in the exhaust of automobiles is "seemingly remote" based on observations of animals exposed to leaded gasoline exhaust. Critical reaction came almost immediately from the scientific community. The bureau kept animal cages well ventilated and did not allow lead dust to accumulate said critics from Harvard Medical School, and this avoided real-world conditions.94

The public controversy pitted respected public health experts such as Henderson of Yale and Alice Hamilton of Harvard against the top automotive engineers in the country.

Many scientists and engineers believed that the anti-knock effect of tetraethyl lead had been discovered by a scientific method and that the criticism of leaded gasoline was anti-scientific. "As there is no measurable risk to the public in its proper use as a fuel, the chemists see no reason why its manufacture should be abandoned," said the New York Times. "That is the scientific view of the matter, as opposed to the sentimental, and it seems rather cold-blooded, but it is entirely reasonable."95

On the other hand, public health experts and specialists in lead poisoning like Hamilton found it hard to believe that anyone could reasonably advocate the sure, slow public poison from the use of lead in gasoline.96



Standard's new tetraethyl lead plant had been built as part of its new relationship with General Motors. "The whole thing was in an evolutionary stage," G.M. President Alfred P. Sloan said later, "and it had to be accepted by the oil industry... The fact that they [Standard] were in the thing in an important way would give the stamp of approval of the biggest oil company on the material. It would give us enormous prestige."97

Although they had a new company to handle the antiknock compound, the still-tentative nature of G.M.'s commitment to tetraethyl lead at this point is evident in the du Pont history of leaded gasoline.

"In the summer of 1924 the extremely hazardous nature of tetraethyl lead was already known to G.M., du Pont and Standard Oil; and the peril which this might involve for the commercial future of the joint enterprise was appreciated. Fatal results in a total of five cases had already attended the handling of the material at Deepwater and Dayton.... Irenee du Pont, in writing to (G.M. president Alfred) Sloan, commented ... 'It [tetraethyl lead] may be killed by a better substitute or because of its poisonous character or because of its action on the engine.' 98

The "better substitute" was probably Kettering's main reason for going to Europe in the fall of 1924, but the ostensible motive was that a secondary raw material (bromine) turned out to be in short supply. Sources in Tunisia and Palestine were thought to be interesting. Kettering sailed in mid-October and met with British colonial officials about Palestine's bromine resources. On October 26, 1924, he arrived in Paris and received a telegram about the disaster at Bayway. Beginning that day and continuing through the week, a flurry of telegrams were charged to his room. G.M. patent attorney James McEvoy, in Paris with Kettering, reported to Sloan that Kettering "is very upset and worried, and neither he nor I can understand how Standard allowed this matter [the Bayway disaster] to obtain such broad publicity. The sit- uation was just as at Dayton, and I do not see why it could not have been handled in the same way."99 Sloan returned McEvoy's letter November 11:

"Unfortunately, something like five men were lost and we received a very great deal of unfortunate publicity. Fortunately for us, although our name was connected with it, the Standard Oil Company's name was more involved than ours... However ... nothing has in any way developed as a result of the accident to throw into the picture anything that we did not know four or five months ago when we sat around the table and analyzed the hazard. Therefore, logically, we should in no way make any change at all in the development of the project. On the other hand, it must be recognized that psychologically we are in a very much different position and it is much more important than it was four or five months ago not to have a repetition of this kind.."

It is interesting that Kettering would travel with McEvoy, the patent expert, when he was ostensibly looking only for sources of bromine. In fact, Kettering, McEvoy and Frank Howard of Standard met with I.G. Farben officials in late November, 1924. Most European researchers had left fuel knocking alone, according to one view, considering it the "happy hunting ground of those who dea in magic."100

However, concern about military defense led to development of strong alternative fuels production programs in many nations without oil reserves such as Germany, France, England, Italy, Hungary, Czechoslovakia, Poland, and others.101

German chemists were also working on low percentage class solutions. In the November,1924 meeting, Bosch gave Kettering a secret new antiknock substance to try out in his engine, but he did not tell him what it was, even when Kettering correctly guessed the secret. The substance was iron carbonyl, and Kettering fired off a telegram, probably to Sloan. The undated draft telegram, written on Hotel de Crillon stationary, with many grammatical lapses and strikeouts, demonstrates Kettering's excited state of mind:102

Badiche (Farben) have new compound antiknock. Co saw demonstration and made few rough measurements -- Requires about two and one half times as much as ours. Cost very low. Can produce their material at 21 cents per pound. This would make a lead I figure that with duty included freight etc. The Their compound would cost seventy cents for equivalent one pound lead. Their proposition is to furnish material at cost and take half the difference between our lead mixture cost and their equivalent as profit. Their compound byproduct of nitrogen fixation plant. They will disclose nature of product after commercial agreements have been made. It is metallo-organic and they feel is covered by our patents. This is so very interesting as must be considered prior to any other things. May be a carbonyl of cheap metal. Non-poisonous.

Kettering's level of interest in iron carbonyl indicates that he was ready, after the deaths in Dayton, Deepwater and then Bayway, to abandon lead and move forward with iron. Tetraethyl lead at the time cost $1.66 per pound from the bromine process and $1.16 from the chloride process.103 To pay an equivalent price of 70 cents would clearly be attractive.

However, when Kettering tried iron carbonyl on a Buick engine while in Europe he was disappointed. Apparently, iron carbonyl caked onto the spark plugs like tetraethyl lead without bromine, and it may have affected the lubricating ability of engine oil. Aware of Ethyl's troubles in the U.S., Bosch stressed that iron carbonyl was "practically non-poisonous and much cheaper to manufacture than tetraethyl lead." In any event, "we weren't as interested in [licensing] iron carbonyl as the IG Farben Co. was in selling it to us," Kettering said later.104

Bosch and other Farben chemists insisted that iron carbonyl did not cause the lubrication problems and cylinder wear that Kettering suspected. "During our own experiments and those made by motor car manufacturers and other reliable people," said a 1926 Farben memo, "these troubles in the lubricating system have never -- not even by way of intimation -- been found. Generally speaking it could be ascertained that the prejudice against the use of iron carbonyl was caused by the -- in itself -- harmless red coating, which is found in the compression chamber... It has been proven by many experiments that a grinding action is not in evidence."105

Ethyl Corp.'s Graham Edgar later said that "tremendous [research] effort to reduce this wear" had been undertaken but no solution had been found.106 Iron carbonyl was commercially marketed in Germany, Italy and other European nations as "Motolin" and "Monopolin" beginning in Sept. 1926 and, according to other researchers, it was "favorably received due to its anti-knock qualities." 107

Ethyl, du Pont and Farben signed several agreements covering sale and manufacture of iron carbonyl antiknock additives in the U.S. in February and August, 1925, but not all was amicable. " I don't blame BASF [a Farben subsidiary] for feeling sore," Irenee du Pont said in June, 1925. "They know Kettering saw a sample of iron carbonyl though they didn't disclose what it was... He was keen enough to recognize what the material was, return home and file a patent application thereon. Without knowing the prior history that appears to them to be a rather sharp practice, though it would have been avoided ... if they'd been candid with Kettering under a pledge not to apply for patent." 108

Kettering later said he did not remember personally applying for a patent on iron carbonyl, but "we knew I.G. Farben had been making iron carbonyl long before I went over there." Contacts continued over use of iron carbonyl until in 1927, du Pont signed an agreement with I.G. Farben to market it in the U.S. Yet ignition and lubrication problems were said to have never been solved.109

In meetings with chemists and in his glimpses of the Farben plant where iron carbonyl was made, Kettering may have also been aware that Farben was manufacturing synthetic methanol from coal at a cost of around 10 to 20 cents per gallon. This, too, could have been a competitive element in the struggle for the antiknock market. Certainly, Ford Motor Co. was aware of it, and provided information about the process to the Surgeon General's committee looking into leaded gasoline in August of 1925.110 Synthetic methanol as a fuel substitute was also mentioned around this time in Industrial & Engineering Chemistry in and in the New York Times.111


After he returned from Europe in December, 1924, Kettering visited Surgeon General Hugh Cumming in Washington. They agreed that a public hearing, which had been requested by public health advocates, would help clear the air. At some point in late 1924 or early 1925, Kettering also visited with Commerce Dept. Secretary Herbert Hoover.

The future president was interested in the Ethyl dilemma, although later the New York Times quoted him as saying that the Commerce Department "had not been asked to take an investigation of the poisonous or non-poisonous qualities of tetraethyl and did not contemplate entering into the present controversy." 112 A Commerce Department report dated May 15, 1925 on alcohol fuel use worldwide shows that Hoover was well aware of the alternatives.113

Over the holidays and during the winter of 1925, Public Health Service representatives visited the Bayway and Deepwater refineries, talked extensively with engineers, and became convinced that safe manufacturing was at least theoretically possible. Du Pont engineers, especially, believed that if given the chance they could create an entirely closed environment safe for workers who handled deadly chemicals. However, during February and early March of 1925, four more workers died in the new ethyl chloride process tetraethyl lead refinery.114

In order to cope with the crisis, someone would have to defend tetraethyl lead to fellow scientists. Midgley took on the task at the American Chemical Society conference in April, 1925. Midgley's discussion began by listing his discovery's benefits - conservation of petroleum, reduction of carbon monoxide, improved mileage and lowered initial cost of cars. Most significantly, he claimed that no alternatives existed to Ethyl gasoline.

Midgley's conference paper, as quoted by a New York Times reporter and published in Industrial & Chemical Engineering, said:

"So far as science knows at the present time, tetraethyl lead is the only material available which can bring about these [antiknock] results, which are of vital importance to the continued economic use by the general public of all automotive equipment, and unless a grave and inescapable hazard exists in the manufacture of tetraethyl lead, its abandonment cannot be justified."86

The sweeping claim was unusual because it directly contradicted Midgley's own work andthat of many other engineers.115

His loyal defense of G.M. notwithstanding, Midgley was removed as vice president of Ethyl and Kettering was forced to step down as president. At the April, 1924 board of di-rectors meeting of the Ethyl Corp. in Standard's headquarters at 26 Broadway, G.M. and Standard executives pointedly noted that Midgley and Kettering had not confronted many of the business problems of building the Ethyl Gasoline Corp.

A hint of the tone of the meeting is found in a memo written shortly beforehand from G.M. President Sloan to fellow board member Irenee du Pont: "I have felt from the very beginning of the formation of this company, in fact, I felt a year before it was formed, that we would make progress much more rapidly and more constructively if we had more of a business side to the development," Sloan also told du Pont that Standard's Walter Teagle agreed that Kettering had to go. Sloan warned du Pont that Kettering had been "violently opposed" to losing control of Ethyl Corp, but that he (Sloan) had left "the boys" (as he called Kettering and Midgley) in place despite serious misgivings, believing that his point would eventually become so obvious that it would have to be recognized.

"We felt that it was a great mistake to leave the management of the property so largely in the hands of Midgley who is en-tirely inexperienced in organization matters."116 Kettering and Midgley would go back into research, where they belonged, he said. Sloan proposed Earl Webb, a G.M. lawyer, as the new president. Kettering later said that he had been "fired to create a position for a man who would make more money." Company historian Joseph C. Robert interpreted this as a "jocular over-simplification."117

Kettering may have wanted to take research in different and potentially less profitable directions. In the summer of 1925, G.M.'s Dayton labs announced a new synthetic alcohol "Synthol" fuel. It was said by the United Press to be a mixture of benzene, alcohol and iron carbonyl, or, by the New York Times account, benzene, tetraethyl lead and alcohol. Both methyl and ethyl alcohols mayhave been involved. Used in combination with a new high compression engine much smaller than ordinary engines, "Synthol" would "revolutionize transportation"118 the articles said, and mo-torists would get 40 or 50 miles per gallon. Thus, as the federal investigation of tetraethyl lead proceeded, Kettering and G.M. had several fall-back positions.


Over 100 representatives of labor groups, oil companies, universities, government agencies and news organizations crowded into a U.S. Treasury Dept. auditorium May 20, 1925, to hear arguments about tetraethyl lead.119 The Interior Secretary, the Assistant Secretary of Treasury, the Surgeon General, and Charles Kettering, president of Ethyl Gasoline Corp., were listed as principal speakers; others from labor, universities and industry are listed in specific panels.

Significantly, Kettering's authority was equated with that of impartial government officials. Kettering opened the conference by describing the development of antiknock fuels. 120

"We found out that with ordinary natural gasoline we could produce certain [antiknock] results and with the higher gravity gasolines, the aromatic series of compounds, alcohols, etc., we could get the high compression without the knock, but in the great volume of fuel of the paraffin series we could not do that."

Frank Howard of Standard also testified.

"Our continued development of motor fuels is essential in our civilization... Now, after 10 years research ... we have this apparent gift of God which enables us to [conserve oil] ... We cannot justify in ourselves in our consciences if we abandon the thing."121

A few moments later, labor representative Grace Burnham stood up said: "It was no gift of God for the [17 workers] who were killed by it and the 149 who were injured."122

Alice Hamilton also spoke, saying lead poisoning was a serious public health issue. "I would like to make a plea to the chemists to find something else, and I am utterly unwilling to believe that the only substance which can be used to take the knock out of a gasoline engine is tetraethyl lead."123

The question of alternatives was originally expected to be featured more prominently at the conference, according to the New York World. "Original plans had called for presentation to the Public Health conference of claims of various persons that they have discovered dopes [additives] for fuels which are as efficient as lead but lack the danger. The conference decided at the last minute, however, that such things were not in its province, since it was called to consider only the danger of lead and not the lack of danger of any other chemical or mineral. For this reason, the conference adjourned after only a one day meeting, where it had been thought at first that four or five days might be taken. Many of the delegates to it held informal conferences today, however, at which fuel dopes were discussed." 124

The Surgeon General ended the conference by announcing that a committee of experts would be appointed to look into the safety of tetraethyl lead.

Meanwhile, other oil companies, especially Sunoco, made a point of finding alternative anti-knock fuels -- a fact well appreciated by Standard.125 Shortly after the PHS conference, Frank Howard wrote in a memo to Kettering that there was a tremendous amount of competition developing. "There are three types of Ethyl Gasoline substitutes now on the market, as follows: 1) vapor-phase cracked products; 2) benzol blends; 3) gasoline from napthenic-base crudes." The "cracked" gaso- line and napthenic crude gasoline had low knock ratings that did not justify the 3 cent premium price, he felt. "Benzol blends are, of course, in another category," Howard said, "...equal or superior of Standard Ethyl Gasoline in knock rating." Howard said that Standard's benzol blend was so well established in the Baltimore-Washington market that they could not replace it. Blending ethyl into higher base octane gasoline from napthenic crude oil would help in New Jersey "where the Gulf No-Nox competition is severe, having a knock value not quite the equal of Ethyl Gasoline on the average, although the difference is very small."

Many refiners had turned their attention to premium antiknock gasolines in order to compete with the new Ethyl additive being sold by Gulf, Standard of Indiana and Standard of New Jersey. These refinery operations raised base gasoline by 20 to 30 of what later came to be called "octane" points. In contrast, tetraethyl lead , in the usual three grams per gallon ratio, raised base gasoline octane by about 9 points. Thus, it was refinery improvements, not tetraethyl lead, that were the major force in developing anti-knock fuels. "The major factor [in improving the engine] was the improvement in refining processes to get a better, more knock-free base gasoline," T.A. Boyd said in a 1960 oral history interview with Frank Howard. "Yes, that's right," Howard responded. 126

The fate of Kettering and Midgley's discovery hung in the balance during the summer of 1925. Although they had repeatedly claimed there were no alternatives, Synthol and iron carbonyl gave them a fall-back position in case tetraethyl lead was banned. But the Public Health Service was not really in a position to exercise federal authority over an industrial hazard. It had no enabling legislation, as Surgeon General Cumming said on several occasions, and there were no regulatory precedents. In the absence of that authority, the committee of experts would have had to have found striking evidence of serious immediate harm to justify unprecidented action. Instead, a committee-directed PHS study in the fall of 1925 found that drivers and garage workers exposed to leaded gasoline showed some "stippling" da-age to red blood cells, but no evidence of outright lead poisoning. Although one quarter of those exposed had over one milligram of lead in fecal samples, these amounts were small compared to a control group of lead industry workers.127

Of course, techniques for measuring lead levels were primitive in contrast with today's standards. It is probable that workers had absorbed amounts of lead that would today be considered dangerous.128 Even then, the results were considered rather high. In a Bureau of Mines final report about the study in 1927, the Surgeon General's Committee report is noted as having found blood cell stippling "to a relatively high degree" in garage mechanics whose exposure had been relatively short - as little as two and a half days.129 Yet in the absense of striking evidence, and with the lack of regulatory authority, the committee could not recommend banning the substance.

Committee member C.E.A. Winslow of Yale recommended that the "search for and investigation of antiknock compounds be continued intensively with the object of securing effective agents containing less poisonous metals (such as iron, nickle, tin, etc.) or no metals at all."130 Winslow had been in correspondence with Ford Motor Co. officials who said that 60,000 gallons per month of synthetic alcohol were being pro- duced by Badische Anilin and Soda Fabrik [BASF of I.G. Farben] "for between 10 cents and 20 cents per gallon . The fuel "has much promise as a mixture with hydrocarbon fuels to eliminate knocking and carbonization," William H. Smith of Ford wrote. 131

These recommendations were not included in the final PHS committee of experts report, issued in January of 1926 which concluded that there were "no good grounds for prohibiting the use of Ethyl gasoline." However, the committee did caution: "It remains possible that if the use of leaded gasolines becomes widespread, conditions may arise very different from those studied by us which would render its use more of a hazard than would appear to be the case from this investigation.... The committee feels this investigation must not be allowed to lapse." 132

The investigation did lapse, and the committee report was repeatedly used to claim a "clean bill of health" for te-traethyl lead. Public health advocates, however, did not regard the outcome as a defeat. Alice Hamilton said later that establishing the precedent of government and scientific influence over industrial hazards was a major victory, even if the specific battle had not been won.133

And thirty years later, P.H.S. employees would reconsider the old controversy and find it "regrettable that the investigations recommended by the Surgeon General's Committee in 1926 were not carried out by the Public Health Service." 134

Still facing competition from refining and high percentage solutions in the early 1930s, the Ethyl Gasoline Corp. decided to end exclusive contracts and sell the additive to most oil companies and distributors. By the late 1930s, tetraethyl lead could be found in nearly 90 percent of all American gasoline. Benzol blends were rare, Kettering's "Synthol" fuel had been forgotten, and attempts by Midwestern farmers to encourage ethyl alcohol as an anti-knock additive had failed.135

It would take another "gasoline famine" to reawaken interest in alternatives. As the leaded gasoline crisis abated in the fall of 1925, Kettering noted that the search for a substitute for petroleum had become problematic: "Many years may be necessary before the actual development of such a substitute," he said. 136

Yet he always held out hope, his friend Charles Stewart Mott said later, "that if a time ever came when the sources of heat and energy were ever used up ... that there would always be available thecapturing of the amount of energy that comes from the sun... One of the ways was through growth of agricultural products ..."137





1 Carl Solberg, Oil Power (NY: New American Library, 1976).

2 David Rosner and Gerald Markowitz, "A Gift of God?" in Dying For Work: Workers Safety and Health in 20th Century America, (Bloomington, Indiana: Indiana University Press, 1989), p. 125.

3 John M. Blair, The Control of Oil (NY: Vintage Books, 1978); Anthony Sampson, The Seven Sisters: The Great Oil Companies and the World They Shaped (NY: Viking, 1975); James Ridgeway: Powering Civilization; the Complete Energy Reader (NY: Pantheon, 1982); Daniel Yergin, The Prize: The Epic Quest for Oil, Money & Power (NY: Simon & Schuster, 1991).

4 Thomas P. Hughes, "Inventors: The Problems They Choose, The Ideas They Have and the Inventions They Make," in eds., Patrick Kelly, et al., Technological Innovation: A Critical Review of Current Knowledge (San Francisco, San Francisco Press, Inc., 1979), p. 177.

5 David Hounshell and John Smith, Science and Corporate Strategy: Du Pont R&D, 1902-1980 (New York: Cambridge University Press, 1988), p. 154. Also, Joseph A. Pratt, "Lettingthe Grandchildren Do It: EnvironmentalPlanning During the Ascent of Oil as theMajor Energy Source," The Public Historian 2, No. 4 (Fall, 1980), p. 35.

6 Joseph C. Robert, Ethyl: A History of the Corporation and the People Who Made It (Charlottesville, Va.: University Press of Virginia, 1983), pp. 122- 123.

7 Harold Williamson, et al., The American Petroleum Industry, The Age of Energy, 1899-1959 (Evanston, Ill.: Northwestern University, 1963), p. 414. Four dead and 49 injured was Williamson's total: Seventeen dead and several hundred injured is Wescott's 1936 du Pont history's total. Contemporary newspapers had the Bayway tragedy at five and the G.M. and du Pont deaths at 6 for a total of 11.

8 Stuart Leslie, Boss Kettering (New York: Columbia University Press, 1983), p. 166.

9 T.A. Boyd, Professional Amateur (New York: E.P. Dutton, 1957); also Rosamond Young, Boss Ket (New York: Longmans, Green & Co., 1961), p. 162.

10 Graham Edgar, "Tetraethyl Lead," paper to the American Chemical Society, New York,Sept. 3-7, 1951, reproduced by the Ethyl Corp.; T.A. Boyd, "Pathfinding in Fuels and Engines," Society of Automotive Engineers Transactions, (April 1950), pp. 182-183; Stanton P. Nickerson, "Tetraethyl Lead: A Product of American Research," Journal of Chemical Education 31, (November 1954), p. 567. Also, S.D. Heron, Development of Aviation Fuels, (Cambridge, Mass.: Harvard University Graduate School of Business Administration, 1950) p. 560.

11 Robert Friedel and Paul Israel, Edison's Electric Light: Biography of an Invention (New Brunswick, N.J.: Rutgers University Press, 1987), p. 249. Also, Frederic Lawrence Holmes, Lavoisier and the Chemistry of Life (Madison, Wisconsin: University of Wisconsin Press, 1985), p. xv.

12 These include:

T. A. Boyd, "The Early History of Ethyl Gasoline," Report OC-83, Project # 11-3, Research Laboratory Division, GM Corp., Detroit Michigan, (unpublished) June 8, 1943, GMI Alumni Institute for Industrial History, Flint, Mich. (Hereafter cited as Boyd, "Early History");

Charles Kettering, "Transcript of Matter on the Story of Ethyl Gasoline," dictated in Florida, 1945, GMI Alumni Institute for Industrial History, Flint, Mich. (Hereafter cited as GMI);

Ralph C. Champlin, Ethyl Corp. Public Relations Dept. "Historical Summary Ethyl Corp. 1923 - 1948," Third Draft, unpublished, also known as the "Green Book," Detroit, 1951, GMI;

Frank A. Howard, "History of the Ethyl Gasoline Corp.," memo to Mr. William Benhem, US Dept. of Justice, April 21, 1927; Defendants TrialExhibit No. 274, U.S. v. E.I. Du Pont de Nemours and Co., 126 F. Supp. 235, p. 9. (Hereafter cited as U.S. v du Pont); and

N. P. Wescott, Origins and Early History of the Tetraethyl Lead Business, June 9, 1936, Du Pont Corp. Report No. D-1013, Longwood ms group 10, Series A, 418-426, GM Anti-Trust Suit, Hagley Museum &Library, Wilmington, Del. (Hereafter cited as Wescott, Origins and Early History.)

13 T. A. Boyd, The Early History of Ethyl Gasoline, Report OC-83, Project # 11-3, Research Laboratory Division, GM Corp., Detroit Michigan, (unpublished) June 8, 1943, GMI, (Hereafter cited as Boyd, Early History).

14 Hughes, "Inventors and the Problems They Chose," p. 177. Also see, Anon., "The Trail of the Arbutus," pamphlet probably published either by Ethyl Corp. or General Motors, Aug. 29, 1951, GMI.

15 "A Report of Fuel Research by the Research Division of the Dayton Metal Products Co. and the U.S. Bureau of Mines," July 27,1918, Midgley unprocessed files, GMI.

16 Application Serial No. 210,687 filed Jan, 7, 1918; Patent No. 1,296,832 issued Mar. 11, 1919, assigned to GM Research Corp.; Also, Chemical Abstracts 13, (1919), p. 1636. Ironically, a patent issued the same day to another researcher was for a 50 percent blend of ethyl alcohol and gasoline with 2 percent castor oil as a binder. (Patent No. 1,296,902).

17 Patent application Serial No. 256,874, filed Oct. 4, 1918, Patent No. 1,491,998 issued April 29, 1924.

18 "A Report of Fuel Research," July 27, 1918, Midgley unprocessed files, GMI.

19 F.O. Clements to H.E. Talbott, Feb. 4, 1919, Midgley unprocessed files, GMI.

20 Howard to Clark, April 16, 1919, Trial transcript, p. 3500, U.S. v. v du Pont.

21 Free Alcohol Hearings, US Senate Finance Committee, 1906, Statement of James S. Capen, Detroit Board of Commerce, p. 59. Capen also said: "Alcohol can be produced from any old thing that has sugar or starch in it, and once given our American inventor a chance at a market as great as this, in a very short time he will have processes that will do away with any fear of scarcity of fuel." Capin said alcohol was "preferable to gasoline" because it was easier to make and harder to control than gasoline, and thus "artificial shortages" could not raise the price in the future.

22 David White, "The Unmined Supply of Petroleum in the United States," Paper presented to the Society of Automotive Engineers annual meeting, Feb. 4-6, 1919. Also see George Otis Smith, "Where the World Gets Oil and Where Will our Children Get It When American Wells Cease to Flow?" National Geographic, Feb. 1920, p. 202.

23 "Declining Supply of Motor Fuel," Scientific American, Mar. 8, 1919, p. 220.

24 Charles F. Kettering, "Studying the Knocks,: How a Closer Knowledge of What Goes on In the Cylinder Might Solve the Problems of Fuel Supply," Scientific American, Oct. 11, 1919, p. 364.

25 This interpretation is found in the 1936 du Pont history of the development of tetraethyl lead written by the legal department in preparation for an anti-trust suit (N.P. Wescott, Origins and Early History, cited elsewhere) and is reinforced by Midgley correspondence in unclassified GMI files.

26 For example, alcohol ran the first internal combustion engine, built in 1826 in Connecticut, and Carl Banz's first horseless carriage experiments in Germany in 1860, according to Lyle Cummins, Internal Fir (Warrenton, Pa.: Society of Automotive Engineers, 1989), p. 81.; also, Horst Hardenberg, Samuel Morey and his Atmospheric Engine SP 922, (Warrendale, Pa.: SAE, Feb. 1992), p. 51.

27 Augustus W. Giebelhaus, "Resistance to Long-Term Energy Transition: The Case of Power Alcohol in the 1930s," paper to the American Association for the Advancement of Science, Jan. 4, 1979.

28 Hal Bernton, Bill Kovarik, Scott Sklar, The Forbidden Fuel: Power Alcohol in the 20th Century (New York: Griffin, 1982).

29 Bill Kovarik, Fuel Alcohol: Energy and Environment in a Hungry World, (London: International Institute for Environment and Development, 1982).

30 Scientific American, April 13, 1918, p. 339.

31 H.B. Dixon, "Researches on Alcohol as an Engine Fuel," SAEJournal, Dec. 1920, p. 521.

32 Scientific American, Dec. 11, 1920 p. 593.

33 Boyd, Early History pp. 75-76.

34 Application Serial No. 417,126, filed Oct. 15, 1920, Patent No. 1,501,568 issued July 16, 1924.

35 Kettering to Midgley, Sept. 14, 1920,

Midgley files, unprocessed, GMI.

36 Testimony of Charles F. Kettering, Trial

transcript p. 3573, US v. du Pont.

37 Leslie, Boss Kettering , p. 155. Ethyl alcohol

was "income" rather than "capital" because it

could be produced from renewable resources.

38 The report is not found in archives; Boyd

recalled it in the Early History, p. 54.

39 Boyd, Early History, p. 60-61, also p. 70.

40 Boyd, Early History p. 54.

41 C.F. Kettering, "The Fuel Problem," undated, probably 1921, Kettering un-processed, GMI.

42 Zimmerschied to Kettering, Feb. 27, 1920; Kettering to Zimmerschied, March 3, 1920, Kettering collection, GMI. Note that carburetors had been built with lacquered cork floats before this time, which was not a problem with gasoline. However, alcohol was a solvent for the lacquer. Therefore, GM switched to metal carburetor floats to accommodate the new international fuel blends.

43 Application Serial No. 362,139, Patent No. 1,578,201, issued Mar. 23, 1926. The patent covers blending alcohol and unsaturated hydrocarbons, particularly olefins formed during the cracking process.

44 Harold Hibbert, "The Role of the Chemist in Relation to the Future Supply of Liquid Fuel," Journal of Industrial and Chemical Engineering 13, No. 9 (Sept. 1921) p. 841.

45 Boyd to Midgley, July 8, 1920, Midgley unprocessed files, GMI.

46 "The Discussion" transcript of SAE meeting discussion, Indianapolis, Oct. 1921. Midgley unprocessed files, GMI.

47 Thomas Midgley, "Discussion of papers at semi-annual meeting," SAE Journal, Oct. 1921, p. 269.

48 F.O. Clements to staff, Sept. 9, 1921, Midgley unprocessed files, GMI.

49 One early reference was to 2,500 compounds in "To Learn the Truth about Leaded Gas," Literary Digest , April 18, 1925, p. 17. A sales manager for Ethyl told the New York Times that 2,400 compounds had been tested. "Scientists to Pass on Tetra-Ethyl Gas," New York Times, May 20, 1925, p. 1. An Ethyl sales pamphlet printed two years later put the number at 33,000. The Story of Ethyl Gasoline, pamphlet (New York: Ethyl Gasoline Corp., 1927), American Petroleum Institute Library, Washington, D.C. In the 1950s, as G.M. public relations personnel prepared a history of the discovery, T.A. Boyd wrote "too much" in the margins of one of the manuscripts next to a note about 143 compounds tested. In 1960, a Kettering biographer quoted Midgley as saying 14,991 compounds were tested; Rosamond Young, Boss Ket (New York: Longmans, Green & Co., 1961); and an Ethyl official in 1980 put the number at 144; John C. Lane of Ethyl Corp., "Gasoline and Other Motor Fuels," Encyclopedia of Chemical Technology, (New York: John Wiley & Sons, 1980), p. 656. The crucial series of tests that were run between August 25 and December 7, 1921 involved 16 elements. Some of these were prepared with different solvents, so that a total of 24 test compounds were run. Dozens of trials were run on each of these under various conditions. This is probably what Boyd had in mind when he said 143 was "too much." If Midgley kept count of every test he ever ran over the seven year period, the number 14,991 might not be questionable. The source of the confusion is simply that the actual day-to-day test diaries used by Midgley, Boyd, Hochwalt and others are not in the public archive.

50 Young, Boss Ket ; Robert, Ethyl. Standard Oil and General Motors officials outside the research labs did not want to use the name Ethyl for the company or the product in 1924, but did so to accommodate Kettering and Midgley.

51 Ferris E. Hurd, (G.M. Attorney), US v du Pont, p. 7986.

52 Midgley to Joseph L. Wood, The Orange Tip Co., Feb. 9, 1922. About 50 other identical letters are found in the Kettering collection, unprocessed Midgley files, GMI.

53 Midgley to Kettering, May 23, 1922, Midgley unprocessed files, GMI.

54 Thomas A. Midgley and T.A. Boyd, "Detonation Characteristics of Some Blended Motor Fuels," SAE Journal, June 1922, page 451. Note: italics indicate a section used at th oral presentation at a June 1922 SAE meetin but not published in the SAE paper; oral pre- sentation from Midgley unprocessed files, GMI.

55 Morrison to Midgley, July 25, 1922, Kettering collection, unprocessed Midgley files, GMI.

56 Thomas Midgley and Thomas Boyd, "The Application of Chemistry to the Conservation of Motor Fuels," Industrial and Engineering Chemistry, Sept. 1922, p. 850.

57 Wescott, Origins and Early History, p. 4.

58 Washington Post, July 24, 1923

59 Stanwood W. Sparrow, "Fuels for High Compression Engines," Report No. 232, U.S. Naval Advisory Committee for Aeronautics, 1925, National Archives. The report also questioned the safety of benzol and alcohol blends due to the potential for separation at extremely low temperatures at high altitudes. Alcohol was used as an sec-ondary injector fuel for aircraft in World War II.

60 Midgley to Lt. B.G. Leighton, Mar. 16, 1923, Kettering collection, Unprocessed Midgley files, GMI. It is interesting to note that the U.S. Airship Shenandoah had been using Ethyl gasoline prior to its catastrophic engine failure and crash in September, 1925. See H.L. Calendar, et. al., "Dopes and Detonation," Engineering, April 9, 1926, p. 475.

61 Midgley to Kettering, "Summary of Present Situation on Antiknock Material," Nov. 20, 1922, Factory Correspondence, unprocessed Midgley files, GMI.

62 Application Serial No. 553,040 filed April 15, 1922, Patent No. 1,605,663 assigned Nov. 2, 1926; Application No. 592,435 filed Oct. 4, 1922, Patent 1,492,953 issued July 20, 1926.

63 Boyd, Early History, p. 193.

64 Ibid, p. 179.

65 Midgley to Dr. R.L. Allen, Sept. 9, 1922, unprocessed Midgley files, GMI.

66 Midgley to H.N. Gilbert, Jan 19, 1923, unprocessed Midgley files, GMI.

67 Boyd, Early History, pp. 164 - 170.

68 William M. Clark to A. M. Stimson, Oct. 11, 1922, A. M. Stimson to R. N. Dyer, Oct. 13, 1922, Dyer to Surgeon General, Oct. 18, 1922, N. Roberts to Surgeon General, Nov. 13, 1922, H.S. Cumming to Pierre Du Pont Dec. 20, 1922, and Thomas Midgley to Cumming, Dec. 30, 1922, all in US Public Health Service Record Group 90, National Archives, Washington, D.C.

69 Midgley to A.W. Browne, Dec. 2, 1922, unprocessed Midgley files, GMI.

70 Midgley to G.A. Round, Vacuum Oil Co., Feb.

14, 1923, unprocessed Midgley files, GMI.

71 Joseph A. Pratt, "Letting the Grandchildren Do It," p. 35, and David Rosner and Gerald Markowitz, Dying For Work , p. 123. The authors describe in detail the progress of the research work and the correspondence between G.M. and the Bureau. Citations here include A.C. Fieldner to Dr. Bain, Sept. 24, 1923; S.C. Lind to Fieldner, Nov. 3, 1923; and the agreement between the Dept. of Interior and General Motors, all in Record Group .70, 101869, File 725, US Bureau of Mines; and letters in file 182, General Classified Files 1923, US Bureau of Mines, National Archives, Washington DC.

72 Boyd, Early History, p. 268.

73 Irenee du Pont to Sloan, June 28, 1924, Wescott, Origins and Early History, p. 21

74 Irenee du Pont to Alfred Sloan, Aug 29, 1924, included as appendix to Wescott, Originsand Early History, B-3.

75 "Midge" to "My dear Boss" Kettering, March 2, 1923, Factory Correspondence, unprocessed Midgley files, GMI.

76 Testimony of Charles F. Kettering, US v. Du Pont, p. 3565.

77 P.S. du Pont to Irenee du Pont, March 24, 1922, "Memo RE: Doping of Fuel," Exhibit C, Wescott, Origins and Early History, p. 9.

78 Silas Bent, "Tetraethyl Lead Fatal to Makers," The New York Times, June 22, 1925. Some 300 other workers were poisoned at the Du Pont plant, according to officials Bent quoted.

79 Ethyl Gasoline Corp. et al. v. United States, 309 U.S. 436, (1940), Dept. of Justice records, National Archives, Washington D.C. See also U.S. v. E.I. Du Pont de Nemours and Co., 126 F. Supp. 235. (cited as U.S. v du Pont), 1952.

80 Testimony of W.F. Harrington, US v du Pont, p. 6487.

81 Robert, Ethyl, p. 121 .

82 Testimony of Alfred P. Sloan, US v. du Pont, p. 2941.

83 Wescott, Origins and Early History, p. 20.

84 Ibid, p. B-4.

85 Testimony of W.F. Harrington, US v du Pont, p. 6487.

86 Memo in response to Wescott's Origins and Early History from Irenee du Pont, June 29, 1936. Govt trial exhibit 775, transcript p. 1852, U.S. v Du Pont.

87 Wescott, Origins and Early History, p. 21.

88 Ferris Hurd, closing statement, US v du Pont, p. 7986.

89 "Mad Gas Kills One," New York Times, Oct. 24, 1924, p. 1. The chemist was also suffering from lead poisoning at the time.

90 "Another Man Dies from Insanity Gas," New York Times, Oct. 28, 1924, p. 1.

91 Trial testimony, p. 2169, United States v. du Pont, US District Court, Chicago Ill., Nov. 18, 1952, 126 F. Supp. 235. (Hereafter cited as US v. du Pont).

92 Wescott, Origins and Early History, p. 22.

93 "An Episode Without Precedent," New York Times, Oct. 31, 1924, p. 18.

94 Rosner & Markowitz, "A Gift of God," p.122.

95 "No Reason for Abandonment," New York Times Nov. 28, 1924, p. 20.

96 Alice Hamilton, Paul Reznikoff and Grace Burnham, "Tetra Ethyl Lead," Journal of the American Medical Association, May 16, 1925, pp. 1481-1486.

97 Testimony of Alfred Sloan, US v du Pont, p. 2941.

98 Wescott, Origins and Early History, p. 21.

99 David Hounshell and John Smith, Science and Corporate Strategy: Du Pont R&D, 1902- 1980 (New York: Cambridge University Press, 1988), p. 154. How exactly the two deaths were handled in Dayton is not known, since memos have not survived. The similarity between the incidents is difficult to judge, but at Bayway, five men suddenly went berserk from a sudden onset of severe lead poisoning in a most dramatic manner, an in close proximity of a highly competitive news market. The Dayton, Ohio and Deepwater, N.J., newspapers were far more willing to defer to their corporate neighbors and not ask embarrassing questions about the accidental deaths of workers.

100 S.D. Heron, Development of Aviation Fuels, (Cambridge, MA: Harvard University Graduate School of Business Administration, 1950), p.560.

101 Bill Kovarik, Fuel Alcohol: Energy and\ Environment in a Hungry World (London: Earthscan, 1982), p. 62.

102 Handwritten note for telegraph office, Kettering collection 87-11.2-153 Box 64, "European trip," probable date Nov. 30, 1924, GMI.

103 By 1937 it would fall to 26 cents per pound, or $3.38 per gallon of full strength TEL.

104 Testimony, Charles Kettering US v Du Pont, p. 3624.

105 "Experiences with Iron Carbonyl in Germany," IG Farben, Government Trial Exhibit No. 722, US v du Pont, 1953. It is difficult to know which side of this technical debate to believe. In many cases research performed in preparation for contract negotiations may be defensive. It is likely that the buyer (G.M.) overstated the problem while the seller (Farben) understated it.

106 Graham Edgar, "Tetraethyl Lead," paper to the American Chemical Society, New York, Sept. 3-7, 1951, Reprinted by the Ethyl Corp.

107 E.I. Fulmer, R.M. Hixon, L.M. Christensen, W.F. Coover in "The Use of Alcohol in Motor Fuels: Progress Report Number I, A Survey of the Use of Alcohol as Motor Fuel in Various Foreign Countries," May 1, 1933, unpublished manuscript, Iowa State University archives.

108 Du Pont to Sloan June 26, 1925 Government Trial Exhibit 715, US v du Pont, transcript p. 3631.

109 Ibid. Also, Nickerson, "Tetraethyl Lead." Note that I.G. Farben was a conglomerate of German chemical companies which included BASF, or Badische Analin and Soda Fabrik, and seven other firms which had merged all assets in 1924.

110 William H. Smith, Ford Motor Co., to C.E.A. Winslow, August 15, 1925, notes the manufacture of 60,000 gallons per month at the Farben plant. C.E.A. Winslow Papers, Yale University archives. Note that Winslow sent this note from Ford to others on the tetraethyl committee and to the PHS, but PHS files on alternatives to leaded gasoline are not found in theU.S. National Archives.

111 "Liquid Fuels of the Future," Industrial & Engineering Chemistry, Vol. 17, No. 6, April 1925, p.334. Also, "Synthetic Marvels Arouse Scientists," New York Times, May 8, 1925, p. 22.

112 "Synthetic Marvels Arouse Scientists," New York Times, May 8, 1925.

113 Homer S. Fox, "Alcohol Motor Fuels," Supplementary Report to World Trade in Gasoline, Minerals Division, Bureau of Domestic & Foreign Commerce, Trade Promotion Series Monograph No. 20 (Washington, D.C.: Dept. of Commerce, May 15, 1925). The report provided detailed statistics on trade volume, duties, tax incentives and laws surrounding the use of alcohol blended fuels, including ethanol and methanol, in France, Germany, England, Italy and 15 other countries were it was routinely used.

114 Wescott, Origins and Early History. Du Pont engineers were not initially successful in creating the closed system they envisioned, a fault which Wescott attributed to pressure from GM to produce more quickly. The fully enclosed processing system would eventually become the basis of du Pont's future tetraethyl lead production, and the death on March 28, 1925 would be the last in the manufacturing and refining area until an incident in the late 1950s, when eight more workers died.

115 See, for example, Thomas A. Midgley and T.A. Boyd, "Detonation Characteristics of Some Blended Motor Fuels," Society of Automotive Engineers Journal, June 1922, page 451. Similar statements about ethyl alcohol, benzene and other anti-knock agents are found throughout the early 1920s. In April, June, July and August of 1925, Industrial & Chemical Engineering published papers by a variety of scientists on alternative fuels, including ethanol from sugarcane and methanol from coal. A May, 1925 article in the Society of Automotive Engineers Journal detailed the work of the Fuel Research Board on alcohol fuel blends in Britain ("Power Alcohol from Tubers and Roots," SAE Journal, May 1925, p.546.)

116 Sloan to Du Pont, March 28, 1925, Government Trial Exhibit No. 678, U.S. v. du Pont et al., US District Court, Chicago, 1953.

117 Roberts, Ethyl, p. 124.

118 "Work on New Type of Auto and Fuel," New York Times, August 7, 1925; also "New Auto, Fuel to Save Costs are Announced," United Press, August 6, 1925.

119 Gulf had discontinued Ethyl sales on Nov. 1, 1924, "in deference to public opinion" ac cording to Wescott, Origins and Early History, p. 25.

120 U.S. Public Health Service, Proceedings of a Conference to Determine Whether or Not There is a Public Health Question in the Manufacture, Distribution or use of Tetraethyl Lead Gasoline, PHS Bulletin No. 158, (Washington, D.C.: U.S. Treasury Dept., August 1925), p. 6. (Hereafter cited as PHS Conference).

121 PHS Conference, p. 106.

122 Ibid, p. 108.

123 Ibid, p. 99.

124 "U.S. Board Asks Scientists to Find New Doped Gas,'" N.Y. World, May 22, 1925, p. 1.

125 For example, Ludlow Clayden, Chief Engineer of Sun Oil Co., predicted 75 to 100 mile-per-gallon fuel in 20 years -- without Ethyl gasoline. "The cost of fuel shouldn't ex- ceed present prices, as it is possible to improve the quality of natural gasoline without resorting to use of Ethyl -- a more expensive product," he said. Clayden was referring to Sunoco's development of catalytic reforming at its Marcus Hook, N.J. refinery that boosted octane by 15 to 20 points -- twice as much as Ethyl and at a much lower cost. See "Predicts Double Gasoline Mileage," New York Sun, Jan. 20, 1926.

126 Howard to Kettering, Sept. 25, 1925, Unprocessed Kettering files, "Cyclo-Gas" file, GMI. Alternatives were an ongoing concern. At one point in 1928, Sloan requested a report on alternatives to Ethyl. At another point in 1931, Boyd identified alternatives in the field. (TA Boyd, "Remarks on Ethyl Gas as Made to the G.M. Technical Committee," March 19, 1931, Box 18, GMI).

127 Kettering Archives oral history project, interview with Frank A. Howard, recorded Sept. 14, 1960, GMI

128 Personal communication, Jerome Niragu, Sept. 1991. An international expert in toxicological studies of heavy metals, Niragu reviewed the original PHS report at this writers request and roughly estimated that blood lead levels would have exceeded 50 to 100 micro- grams per milliliter in the group of highly affected garage workers. The currently acknowledged safe blood lead level is 10 micrograms per milliliter.

129 R.R. Sayers, A.C. Fieldner, et al., Experimental Studies on the Effect of Ethyl Gasoline and its Combustion Products," U.S. Bureau of Mines (Washington, D.C. U.S.GPO, 1927), p. 12.

130 C.E.A. Winslow, "Recommendations for the Drawing Up of a Report on the Use of Lead Tetra-Ethyl Gasoline by the Public," memo to P.H.S. committee members, Dec. 31, 1925, Box 101, Folder 1801, C.E.A. Winslow papers, Yale University Library, New Haven, Ct.

131 W.H. Smith to C.E.A. Winslow, Box 101 Folder 1800, C.E.A. Winslow papers, Yale University. Forwarded to Surgeon General in Sept. 1925.

132 "The Use of Tetraethyl Lead Gasoline in its Relation to Public Health," Public Health Bulletin No. 163, U.S. Public Health Service, Treasury Dept. (Washington: GPO, 1926).

133 Angela Nugent Young, "Interpreting the Dangerous Trades: Worker's Health in America and the Career of Alice Hamilton, 1910-1935," Ph.D. Dissertation, Brown University, 1982.

134 "Public Health Aspects of Increasing Tetraethyl Lead Content in Motor Fuel," Report of the Advisory Committee on Tetraethyl Lead to the Surgeon General, PHS publication No. 712 (Washington, D.C. Public Health Service, March 30, 1959), p. 2.

135 Bernton, The Forbidden Fuel .

136 "May Take Years to Find Good Gasoline Substitute," New York Times, Oct. 25, Section 9, p. 14. Also, Associated Press, "Gas Substitutes Held Uneconomical," Detroit Free Press, October 2, 1925.

137 C.S. Mott, Kettering Oral History Project, Interviewed by T.A. Boyd, October 19, 1960, GMI.