SUBSTITUTES FOE GUNPOWDEK. 
67 
upon its surface, excepting arsenic and antimony, which however may be de¬ 
tected in the gas evolved. He recommends the organic matter to be destroyed 
by the usual methods, the acid liquid concentrated, and ribbon magnesium in¬ 
troduced as long as any deposit is formed. 
Chlorate of Quinine. 
Mr. C. R. C. Tichborne, having been requested by Dr. Lyons to prepare him 
some pure chlorate of quinine, found that this salt could be best prepared from 
chlorate of barium. He describes its characters as follows:—When crystal¬ 
lized from a watery solution it forms small mushroom-shaped masses, which, on 
examination, are found to consist of filiform snowy-white crystals radiating 
from a centre. Crystallized from a spirituous solution, it resembles more the 
ordinary salts of quinine in appearance. Heated gently upon a spatula, it 
gradually melts, and after a little time goes off with a vivid combustion, which, 
if the salt is dry, sometimes amounts to an explosion. A carbonaceous residue 
is left. Treated with hydrochloric acid and gently warmed, it evolves chlorine 
copiously, which may be recognised by its smell. On adding ammonia in ex¬ 
cess to this mixture an emerald-green colour is developed. It is very soluble in 
boiling water, but rather insoluble in cold. When pure, it crystallizes with 
difficulty from this solution, but much more readily if it contains traces of any 
of the ordinary salts of quinine; 
Formation of Hitrite of Potash. 
I^I. Woehler states that when ammonia is decomposed by permanganate of 
potash, the disengagement of nitrogen is very feeble; and if the liquid be 
filtered after decolorization, the presence of nitrite of potash in it may be 
demonstrated by the evolution of nitrous vapours on the addition of sulphuric 
acid. 
Specific Gravity of Mercury. 
Dr. Balfour Stewart has recently made at the Kew Observatory some deter¬ 
minations of the specific gravity of mercury. At 60° F., he found it to be 
13*569 as compared with water at the saipe temperature. 
ON RECENT PROGRESS IN THE HISTORY OF PROPOSED SUBSTITUTES 
FOR GUNPOWDER. 
BY PKOFESSOR F. A. ABEL, F.R.S., V.P.C.S., CHEMIST TO THE WAR DEPARTMENT. 
(JDelivered at the Royal Institution, May 4, 1866.) 
The changes which have been effected in the composition of gunpowder since its first 
application as a propelling agent have been limited to small variations in the proportions 
of its constituents. But the modifications which have from time to time been intro¬ 
duced into the details of its manufacture, e.g. the preparation of the ingredients, their 
incorporation, and the conversion of the mixture into compact masses (grains, etc.) of 
different size and density, have been sufficiently important and successful to secure the 
fulfilment by gunpow'der, in a more or less efficient manner, of the very various require¬ 
ments of military science and of different branches of industry. 
The characteristics of gunpowder, as an explosive material of permanent character, 
the action of which is susceptible of great modification, are mainly ascribable to the 
peculiar properties of the oxidizing agent, saltpetre. Frequent attempts have been 
made to replace this constituent of gunpowder by other nitrates (such as those of 
sodium, lead, and barium); but, although materials suitable for blasting operations 
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