III. On a New Combustible Gas

Extract

It has been generally known for several years, that, when the acetic acid formed by the distillation of wood is rectified, there is obtained a transparent spirituous liquor, analogous in many respects to alcohol, though very different in others. This liquid has received the name of pyroxylic spirit. It is manufactured by Messrs Turnbull and Ramsay of Glasgow. I have been in the habit for several years of employing it for combustion in lamps instead of alcohol. It is a good deal cheaper, and raises just as good a heat as alcohol; for I can make the small platinum crucible, which I use for drying the products of analysis, red-hot by means of a pyroxylic spirit lamp in a few minutes.

Pyroxylic spirit is as limpid and colourless as alcohol. Its specific gravity, when well rectified, is 0.812. It has an agreeable smell, not, however, quite free from that of naphtha. Its taste is very disagreeable, owing, I believe, to a small portion of naphtha, or empyreumatic oil, which it holds in solution, and from which we cannot free it by any known process. A set of experiments on pyroxylic spirit by Messrs Macaire and Marcet was published in the Bibliotheque Universelle for October 1823. These gentlemen have described several of its properties, and subjected it to an analysis, from which it appears that, like alcohol, it is composed of hydrogen, carbon and oxygen, though the atomic proportions are different.