374 
MINUTES OF PROCEEDINGS OF 
It may arise from decomposition of tlie gun cotton, atmospheric dampness 
having brought about a partial reconstitution of the cellulose. 
This assumption granted, the acid reaction just adverted to should be 
local, affecting the material in particular spots only. This seems a necessary 
deduction, having regard to the long process of steeping in water to which 
LenFs gun cotton is exposed in the course of manufacture. By this 
steeping process the cotton should otherwise be utterly destroyed. 
Possibly the tetra and penta nitro cellulose are more liable to decompo¬ 
sition; but only traces of these bodies are to be found in LenFs gun 
cotton, as experiment amply demonstrates. Were it otherwise, analyses 
should make known (which they do not) a deficiency of carbon and 
hydrogen below the theoretical quantity. 
Carbon. 
Hydrogen. 
Tri-nitro. 
24*2 
2*3 
o 
Tetra-nitro. 
1 
21-0 
1-7 
Tenta nitro. 
O 
18*6 
1*3 
But some specimens of LenFs cotton do not even yield traces of decom¬ 
position. A parcel of Hirtenberg cotton was laid for six weeks in a pond, 
and not subsequently treated with potash. It was then deposited in a 
running stream, afterwards exposed for one month to the air; being subjected 
to all the various influences of dew, rain, and sun, day and night, continuously. 
It retains all its original explosive qualities, and fails to redden litmus 
paper, even though the latter be wrapped in a mass of this cotton and allowed 
to remain for many days. The results of an analysis of this cotton were 
almost identical with the calculated elements of tri-nitro cellulose, as the 
following table makes apparent:— 
Calculated. Found. 
Carbon. 24*2 24’4 
Hydrogen. 2*3 2*8 
The redness of litmus paper that sometimes occurs may also result from 
traces of organic acids, formic and acetic acids for example, both which may 
emanate from the turpentine of the pine-chests in which the gun cotton is 
stored. 
[Some assumptions and arguments used by the Reporters under this heading, in support of the 
stability of gun cotton, are by no means calculated to establish that point; on the contrary, their 
perusal leaves the impression that the distinguished Austrian chemists are, themselves, not confident 
regarding the unalterable character of the gun cotton, and that certain indications of some kind of 
change (whether transient or continuous, remains to be proved), which have been observed by them¬ 
selves, as well as pointed out by others, do not as yet admit of satisfactory explanation. It is quite 
beyond doubt that the completely finished gun cotton from Hirtenberg, which has undergone the 
most rigid purification from the acids used in its production, (or, gun cotton prepared at other places, 
strictly according to the system laid down by General Lenk), does exhibit an acid reaction after brief 
exposure to strong daylight. Ample proof has already been obtained, by the experiments carried 
on in this country, that an acidity will become manifest, in the perfectly purified gun cotton, during 
the drying process; and that this acidity remains manifest, at any rate for some considerable time 
