The Romance of Modern Chemistry

EXPLOSIONS AND EXPLOSIVES natural result is that these modem explosives go off with much greater rapidity than gunpowder. It may seem strange to the reader that we can prevail on atoms of carbon, hydrogen, nitrogen, and oxygen to form for a time a peaceable combination which is ultimately to be rent asunder with such violence, and it must be confessed that the arrangement into which they are coaxed is some- what of the nature of an unstable equilibrium, easily upset by any irritating cause. In this respect these high explosives have some resemblance to nitrogen iodide and mercury fulminate, but the process of explosion in the former cases is a real combustion, which the explosion of nitrogen iodide and fulminate is not. Gun-cotton, nitro-glycerine, and picric acid, which either alone or in combination with other substances form the majority of the high explosives, are obtained by the action of nitric acid on cellulose, glycerine, and carbolic acid respectively. Nitric acid is a substance which contains a large proportion of oxygen, and its action on these materials is such that new substances are formed provided with a good deal of the oxygen which was previously in the nitric acid. The various explosives just mentioned are alike in containing a particular group- ing of nitrogen and oxygen atoms known to chemists as the “ nitro ” group, and gun-cotton and the rest of them are therefore frequently referred to as the “ nitro- explosives. ” It is indeed very remarkable that a harmless thing like ordinary cotton when treated with nitric acid should undergo such a fundamental change, and be converted into a powerful explosive. Great care has to be taken in the process of manufacture, and only the best white cotton waste, perfectly free from grease and dirt, can 174