From the violet vapours of iodine, we’ll switch to a substance that explodes, but without producing smoke. In fact, the discovery of this substance and its claim to fame came from the fact that it could be used to replace gunpowder.
The first recorded observation about nitrocellulose comes from Henry Braconnot, director of the Botanic Garden in Nancy, France, in 1833. Braconnot noted that starch, sawdust and cotton wool became very inflammable when treated with concentrated nitric acid.
For the years that followed, this merely remained a chemical curiosity. But Christian Friedrich Schonbein was just about to change that. He was born in Germany and moved to the University of Basel, where he spent the rest of his life.
Stems from the kitchen
Legend has it that Schonbein, who had this habit of experimenting at home against his wife’s wishes, had been distilling nitric and sulphuric acids. When the flask containing these acids broke, spilling the contents on the kitchen floor, Schonbein spontaneously reached out for the cotton apron and wiped the floor dry.
On leaving the apron to dry, Schonbein had prepared nitrocellulose without intending to and noticed that it burst to flames, without leaving any residue. Schonbein announced the discovery of his revolutionary explosive substance in 1846 and it came to be known as guncotton. He wasted no time, and acquired patents for his substance from Britain and United States (on December 5, 1846).
Gunpowder, a mixture of charcoal, sulphur and potassium nitrate, was the dominant explosive during that time. As it left a lot of smoke and wasn’t as effective as guncotton, efforts were immediately undertaken to replace it.
Not easy to contain
The early history of guncotton was peppered with accidents as people hadn’t fully understood the properties of nitrocellulose and that it is unstable. Schonbein, who also discovered and named ozone, died in 1868 when many were still grappling with the question of how best to contain it.
In that same year, Frederick Abel, an English chemist and explosives expert, developed methods in which guncotton could be manufactured more safely. In the 1880s, Abel, along with Scottish scientist James Dewar, patented a smokeless propellant that consisted of guncotton and became the main form of gunpowder.
Even though all initial attempts were clearly in favour of making guncotton a superior explosive when compared to other available options during the time, it has now metamorphosed to be the principal ingredient in collodion, which is used for coating things, chiefly in surgery. Guncotton could have been put to use to hurt and kill, but instead, the material is now used in healing.
