HISTORICAL NOTE

Toying With a Ridiculous Material The shortage of natural rubber during before Wright. The patent filing and rights to the product from General the Second World War prompted research award dates favor them, also. Electric, renamed it Silly Putty, started for alternatives. Substituting silicon for Whether either group knew what the packaging it in plastic eggs as an Easter carbon—the backbone of natural rubber other had created is not known, but it made promotion, and convinced the owners of chains—quickly became a major line of little difference because “no use was appar- Nieman-Marcus and Doubleday Book - investigation, but it would take years of ent at the time,” as Warrick wrote. What is stores to carry the product. The New research to produce usable silicone rubber not in dispute is that a unique material Yorker published another piece in the materials. Along the way, groups at both had been born. According to the official August 26, 1950 issue describing a the Mellon Institute in Pittsburgh, Web site (www.sillyputty.com), it has reporter’s visit to a Doubleday Bookstore. Pennsylvania (through a fellowship spon- many interesting properties: “It stretches The owner of the store announced sales of sored by Dow Corning) and General without breaking, yet it can be ‘snapped 10,000 eggs of Silly Putty in the past Electric in New Haven, Connecticut, acci- off’ cleanly. It bounces higher than a rub- month, mostly to adults claiming it was dentally stumbled across a novel material ber ball. It floats if you shape it in a certain for their children. Hodgson agreed that the that has fascinated generations of children way, yet sinks in others. It can pick up product was mostly for adults: “It means and adults and started perhaps the silliest pencil marks from pages and comics from five minutes of escape from neurosis,” debate in the history of science: Who some newspapers. If you slam it with a Hodgson said. “The inherent ridiculous- invented Silly Putty? hammer, it keeps its shape, yet if you push ness of the material acts as an emotional The official line is that in 1943 James with light, even pressure, it will flatten release to hard-pressed adults.” He also Wright, an engineer working in General with ease.” More technically, according to noted that it was excellent for cleaning ink Electric’s New Haven laboratories, acci- Chemical & Engineering News, “Silly Putty out of dirty typewriter keys. The New dentally put a drop of boric acid into sili- is a dilatant compound, which means it Yorker article resulted in orders for a quar- cone oil, and found that the resultant has an inverse thixotropy—that is, as a ter million eggs in just over three days. gooey material bounced when he threw it viscous suspension or gel, it becomes solid Hodgson died in 1976 with an estate on the floor. It also stretched more than under the influence of pressure.” worth $140 million, but by then his prod- natural rubber. After experimenting with uct had achieved popularity around the various compositions, Wright applied for world—and beyond. In 1968, the Apollo 8 a patent on a “Process for Making “Apollo 8 astronauts took Silly astronauts took Silly Putty to the moon, Puttylike Elastic Plastic, Siloxane Deriva- Putty to the moon. . . to stick tools using it as a stress reliever and to stick tive Composition Containing Zinc tools to the spacecraft’s walls. In 1977, Hydroxide” on December 23, 1944; he was to the spacecraft’s walls.” Binney & Smith, manufacturer of Crayola awarded U.S. Patent Number 2,541,851 on Crayons, bought Silly Putty and continue February 13, 1951. Warrick and McGregor abandoned the to market it today. In 2000, to celebrate However, Earl L. Warrick and Rob Roy material after obtaining the patent, but the 50th anniversary of this novelty, the McGregor at Mellon Institute, working General Electric put some effort into find- Smithsonian Institution put vintage eggs for Dow Corning, may have a better ing possible applications. In the Novem - of Silly Putty into its “Material World” claim to the invention. They were experi- ber 25, 1944, “Talk of the Town” section display of significant materials that have menting with ways to make polydi- of the New Yorker magazine, a correspon- shaped American culture. Ironically, methylsiloxane (PDMS) fluids more vis- dent described a cocktail party thrown by though Wright’s General Electric product cous. At some point, they, too, added General Electric at a New York Engi- evolved into the original Silly Putty, the boric acid to the mix, with the same neers’ Club to introduce their bouncing raw material for Silly Putty has been results. As Warrick recalled in his mem- putty to the press. Each atten dee received made since 1959 by Warrick and oir Forty Years of Firsts: The Recollections of a ball of what they now were calling McGregor’s Dow Corning Corporation a Dow Corning Pioneer, “By late summer “nutty putty” and a scotch and soda, disguised under the product name 3179 1940 we knew how to carry fluids to a which led to predictable high-jinks, Dilatant Compound. ‘gummy’ or rubbery state, but we still including draping a General Electric TIM PALUCKA had not developed a silicone rubber. One chemist with stretched ribbons of the of our attempts produced instead a curi- putty. A public relations agent present FOR FURTHER READING: Earl L. Warrick, ously resilient material which we called proclaimed silicone to be the “eighth Forty Years of Firsts: The Recollections of a ‘bouncing putty.’ We knew the substance wonder of the world.” In 1945 in an effort Dow Corning Pioneer. (McGraw-Hill was not the polymer we were looking for, to drum up ideas, the company also sent Publishing Company, New York, 1990), but we added fillers to it and took advan- samples to engineers worldwide. The pp. 27–28, 176; Ann Thayer, “What’s That tage of its unique properties to astound preoccupation of these engineers with Stuff? Silly Putty,” Chemical & Engineering visitors by bouncing it off the ceilings and finding some useful application for this News, 78 (48) (November 27, 2000), p. 27; walls of our laboratories.” strange material often brought their other “Silicone” in the New Yorker, XX (41) They applied for a patent on March 30, work to a complete halt, and in every (November 25, 1944), pp. 18–19, author 1943, for “Treating Dimethyl Silicone case was of no avail. unidentified; “Here to Stay” in the New Polymer with Boric Oxide,” and were Finally, according to one version of the Yorker, XXVI (27) (August 26, 1950), pp. awarded U.S. Patent Number 2,431,878 story, an unemployed advertising man 19–20, author unidentified; “Silly Putty on December 2, 1947. So, if Warrick’s named Peter Hodgson discovered nutty University,” Binney & Smith’s Official memory is correct, he and McGregor putty at a party in 1949 and saw its possi- Web site, www.sillyputty.com (accessed invented bouncing putty three years bility as a novelty toy. He purchased the February 2007).

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