1847

Nitroglycerine

Christian Friedrich Schönbein (1799–1868), Théophile-Jules Pelouze (1807–1867), Ascanio Sobrero (1812–1888), Alfred Nobel (1833–1896)

Gunpowder reigned for centuries as the world’s most powerful explosive, until Italian chemist Ascanio Sobrero’s 1847 discovery of an explosive that today we know as nitroglycerine. Sobrero studied under French chemist Théophile-Jules Pelouze, who had worked with guncotton, made by treating cotton with nitric acid, in a process that we now know created nitrate esters on cotton’s cellulose chains. This “nitrocellulose” had been discovered in a spectacular accident in 1832 by the German chemist who discovered ozone, Christian Friedrich Schönbein, when a cotton apron he used to wipe up a spill of nitric and sulfuric acid dried next to the fireplace and then burned up in an explosive flash. But guncotton was still too dangerous and unstable to replace gunpowder (as the explosion of some large-scale production runs unfortunately demonstrated).

Sobrero’s breakthrough came when he nitrated simpler carbohydrate, the syrupy three-carbon glycerin. The resulting nitroglycerine was so explosive, and so hard to handle, that Sobrero didn’t disclose his work for some time, warning correspondents in the strongest possible terms to avoid it. Undaunted, another student in Pelouze’s lab, chemist Alfred Nobel, went home to Sweden in search of a way to make nitroglycerine stable enough to handle. Soaking it into an absorbing material worked, and dynamite was born (as were the beginnings of Nobel’s fortune, which would eventually fund the prizes named after him). Nobel’s hope that such explosives would make wars too terrible to wage, though, was a grievous misreading of human nature.

Several nitro compounds are well-known explosives, including TNT (trinitrotoluene) and the even more powerful RDX (Research Department explosive), used extensively starting in World War II. Their effectiveness comes from carrying oxygen molecules in their structures and their decomposition to nitrogen gas, a very stable substance that provides a large downhill energetic boost (like the formation of aluminum oxide in thermite). Chemists (well, chemists who would prefer to have reasonable life spans) know that any compound that can find an easy path to plain nitrogen should be viewed with suspicion and handled with care.

In its early days, dynamite was enough of a novelty to be the subject of advertisements, such as this one for the Aetna Dynamite Company of New York, c. 1895.