SUBSTITUTES FOR GUNPOWDER. 
The name trinitro-cellulose has therefore been assigned to gun-cotton, its constitution 
being expressed by the formula Cq | ^ > O 5 . Hadow’s conclusions have been con- 
•, Schrotter, and Schneider, 
firmed by other chemists. 
who have analysed specimens of gun-cotton prepared under Von Lenk’s directions. But 
a Keport upon the Austrian Gun-cotton was published in 18G4 by Pelouze and Maury, 
in which the formula C 24 H 3 gOig, 5 NoO^ is assigned to the product of Von Lenk’s process; 
the conclusions of those chemists being founded partly upon some analytical results, and 
partly upon the increase of weight which they found cotton to sustain, when submitted 
to treatment with the mixed acids. They found the greatest increase in weight to be 78 
per cent., a number slightly in excess of that which would correspond to the require¬ 
ments of the formula which they adopt. 
An experimental inquiry into the composition of gun-cotton, as obtained by Von 
Lenk’s process, has been instituted by Mr. Abel; and the very numerous analytical and 
synthetical results which he has obtained confirm the correctness of the formula assigned 
by Crum and Hadow to the most explosive gun-cotton, and demonstrate satisfactorily 
that the products obtained by following strictly the instructions given by Von Lenk are 
invariably trinitro-cellulose, in a condition as nearly approaching purity as a manufac¬ 
turing operation can be expected to furnish. 
The most explosive gun-cotton is perfectly insoluble in mixtures of ether and alcohol; 
but by varying the proportions and strength of the acids employed for the conversion 
of cotton, products of less explosive character are obtained, which are more or less freely 
soluble in ether and alcohol (furnishing the w'ell-known material collodion). If, there¬ 
fore, in manufacturing gun-cotton, the conditions essential to the production of in¬ 
soluble pyroxylin are not strictly fulfilled, the uniformity of the product will suffer. 
The ordinary products of manufacture are never altogether free from soluble gun¬ 
cotton ; but the proportion present is small and very uniform, amounting to about 1’5 
per cent. They contain, besides, a small quantity (about 0‘5 per cent.) of matter soluble 
in alcohol alone, and possessed of acid characters, which is evidently produced by the 
action of nitric acid upon such small quantities of resinous or other matters foreign to pure 
cellulose, as are not completely removed from the cotton fibre by the purification which it 
receives. 
There appears good reason to believe that this impurity in gun-cotton is of compara¬ 
tively unstable character, and that the great proneness to spontaneous decomposition which 
has been observed by Pelouze and Maury, De Luca, and others, in some specimens of 
gun-cotton, is to be ascribed in great measure to the existence in those specimens of 
comparatively large proportions of those unstable bye-products. 
One hundred parts of carefully-purified cotton wool have been found by Mr. Abel to 
furnish from 181'8 to 182-5 parts of gun-cotton. The increase which perfectly pure 
cellulose should sustain by absolutely complete conversion into a substance of the formula 
CgH-NgOji (ti'initro-cellulose) is 83-3; the above results are therefore strong confirma¬ 
tions of the correctness of this generally-accepted view of the composition of giin-cotton. 
In carrying out the actual manufacturing process, as prescribed by Von Lenk, somewhat 
lower results are obtained, because of impurities existing in the cotton employed, and of 
loss of product during its purification. 
Very extensive experiments are in progress at Woolwich, with the view of examining 
fully into the extent of liability to change of gun-cotton when preserved in store, or ex¬ 
posed for prolonged periods to light and to degrees of heat ranging between the ordinary 
atmospheric temperatures and that of boiling water. The results hitherto arrived at, 
though they have shown that, under severe conditions, gun-cotton is liable to decompose, 
have not confirmed the conclusions arrived at by the French chemists, with regard to the 
great instability of the material. Thus, De Luca states that all specimens exposed by 
him to sunlight decomposed either on the first day or within a few days. But, at Wool¬ 
wich, no single instance of such rapid decomposition of gun-cotton, made by the present 
process, has been noticed. A very gradual and slight development of gas occurs after a 
time when the substance is exposed to sunlight; but the quantity which has been col¬ 
lected from specimens exposed at Woolwich to direct day- and sunlight for two years and 
a half, is very small, and the gun-cotton has in all instances preserved its original ap¬ 
pearance. Pelouze and Maury state that gun-cotton always decomposes perfectly within 
a few days, by exposure to temperatures of 55°-60° C. (ISO^-lIO"^ F.), and they lay 
