The laboratory would be filthy with bromine, and you wondered when the TNT was going to detonate! [laughter]…Oh, God, it was marvelous times! The Germans have a word to describe certain persons as tierisch ernst, which means having an animal-like seriousness about them. I must say there was very little of that [laughter] in those days! [laughter]
When Louis Fieser came down to the lab, smoking his ever-present cigarette, the grad students would play pranks on him.
Louis would come in to talk to his people and would invariably throw his cigarettes, still burning, into the sink. And so the game was to try to guess when he was coming down and then pour ether in [laughter] the sink in the hope that it would catch fire. [laughter]
In the hope that it would catch fire!
Fire was not just of intellectual interest to the people in Fieser’s basement lab. It was also an obsession, a fixation. So when Hoyt Hottel told the subcommittee that something in one of DuPont’s paint mixes would spontaneously burst into flames, who instantly raised his hand? Fieser, of course. I’ll look into that. And to help him with his investigation, Fieser immediately turned to another member of his basement coterie. In his memoirs, he writes, “I volunteered chiefly because I had available in my peacetime research group a man ideally qualified to experiment with and evaluate a hazardous chemical. Dr. E. B. Hershberg.”
I spoke to E. B. Hershberg’s son Robert Hershberg and asked him how his father first connected with Fieser. Robert replied: “First, he’s from the Boston area, [and] I think the very quick and short answer was there were limited places for employment for Jews, and Fieser couldn’t care less about religion. So that’s the lab he wound up in.”
E. B. Hershberg was, in Louis Fieser’s words, “a masterful experimentalist in organic chemistry…also versed in engineering, in mechanical drawing, in carpentry…and in photography…Furthermore Hershberg…was experienced in the handling of military explosives, fuses, poison gases, smoke pots, and grenades” and had invented a long list of devices, including “the Hershberg stirrer, the Hershberg stirring motor, and the Hershberg melting point apparatus.”
As Robert recalled:
In our basement we had defused bombs and things of that nature, and [I have] pictures of explosions that occurred. And some of the incendiary devices were in the desk drawers…There were things like notebooks that had incendiary devices in them, that if you were captured, you pulled the pen out, [and] you had half an hour to write everything down and what you wanted and get out of there before it blew up and burned down the building.
That was E. B. Hershberg.
So Louis Fieser went to Delaware to investigate the DuPont compound that made paint catch on fire: divinylacetylene. After he returned to Harvard, he and Hershberg started cooking up batches of it. They would put the batches in pans and place them on the windowsill of Fieser’s basement lab. They noticed that the substance gradually changed from a liquid to a thick, viscous gel. They poked the gel with sticks. Then they set fire to it and noticed—and I’m quoting here from Fieser’s book, because this was the crucial insight—“that when a viscous gel burns it does not become fluid but retains its viscous, sticky consistency. The experience suggested the idea of a bomb that would scatter large burning globs of sticky gel.”
You drop the bomb, and the gel scatters. And it doesn’t just burn itself out. Big globs of gel fly in every direction, and those globs stick to whatever surface they land on—and keep burning and burning and burning.
Hershberg and Fieser now had to find a way to test this new concept of incendiary gels. So they built a little two-foot-tall wooden structure in the lab and compared how well various gel formulations did in burning it down. Divinylacetylene was good. But a gel made of rubber and benzene was better. And gasoline was even better than benzene. They tried amber-colored smoked sheet rubber. Pale crepe rubber. Rubber latex. Vulcanized rubber. They made a prototype and took it with them in a suitcase on the train to Maryland, giving it to the porter to carry. The porter said, “It feels heavy enough to be a bomb.”
Next they tried aluminum naphthenate, a sticky black tar made by a chemical company out of Elizabeth, New Jersey. The tar didn’t mix well with gasoline, but they solved the problem by mixing in something else called aluminum palmitate. Gasoline mixed with aluminum naphthenate plus aluminum palmitate.
Napalm.
Robert Neer, author of Napalm: An American Biography, told me why napalm is so effective:
If you want an effective incendiary, something that is sticky is much more effective than something that is not sticky, because it actually adheres to whatever it is transferring its radiation energy into. And that’s why napalm is so effective.