Page:Popular Science Monthly Volume 2.djvu/75

Rh light structure, from one of which rises a tall chimney, instrumental in raising steam to drive a 10-horse-power sawing-machine, which rapidly creates the "wood-powder" to be turned into use for the gun by the following process:

The grains, being collected in a mass, are subjected to a treatment of chemical washing, whereby calcareous and various other impurities are separated, leaving hardly any thing behind save pure woody matter, cellulose or lignine. The next operation has for its end the conversion of these cellulose grains into a sort of incipient xyloidine, or gun-cotton material, by digestion with a mixture of sulphuric and nitric acids. Practically it is found that absolutely perfected xyloidine (of which ordinary gun-cotton is the purest type) not only decomposes spontaneously by time, the chief products of combustion being gum and oxalic acid, but it is, moreover, liable to combustion of a sort that may be practically called spontaneous, so slight and so uncontrollable are the causes sufficing to bring it about. Cellulose or woody matter, otherwise termed lignine, partially converted to xyloidine is, the inventor affirms, subject to neither of those contingencies. Our readers will understand that, inasmuch as the wood used as a constituent of the Schultze gunpowder is not charred, its original hydrogen is left, and by-and-by, at the time of firing, will be necessarily utilized toward the gaseous propulsive resultant. Next, washed with carbonate-of-soda solution and dried, an important circumstance is now recognizable.

The grains, brought to the condition just described, are stored away in bulk, not necessarily to be endowed with final explosive energy until the time of package, transport, and consignment. Only one treatment has to be carried out, and it is very simple. The ligneous grains have to be charged with a certain definite percentage of some nitrate, which is done by steeping them in the nitrate solution and drying. Ordinarily a solution of nitrate of potash (common saltpetre) is employed; but, in elaborating certain varieties of white powder, nitrate of baryta is preferred.

Having traced the new powder to its final stage, we may contemplate it under the light of two distinct scrutinies—theoretical and practical. Review of the chemical agencies involved, or that may be evolved, suggests the reaction, especially under prolonged moisture, of the sulphur and nitre of ordinary powder, whereby sulphide of potassium should result. Practice is confirmatory: under the condition indicated sulphide of potassium, more or less, does result, and proportionate to the extent of decomposition is the powder deteriorated. Inasmuch as the Schultze gunpowder is wholly devoid of sulphur, so is the particular decomposition adverted to impossible; and theory, at least, fails to suggest any other decomposition as probable or even possible.

All the buildings requisite for manufacturing this explosive are cheap