84 REPORT—1863. 
in quality, especially where the primitive method of preparing it is followed. 
Still, in theoretical disquisitions upon gunpowder, charcoal is taken into 
account as pure carbon.” 
(3) “In the magazines of gun-cotton at the Neustadter Haide, there are 
stores of various years. Inthe laboratory of the University there are samples 
of Hirtenberg gun-cotton of three several years, which haye been examined 
by the above named artillery officers, and they have been found not to differ 
materially in their composition from trinitro-cellulose. For instance— 
Trinitro- No. 3. No. 6. No, 14, 1862 
In 100 parts. | cellulose, 1856. 1860. 1862. ; 
calculated. —--——_--_--_, ——, __ |—_—— 
| eat ee al tb: Miia ide, yor <cosen tae 2 
Carbon ..2).. 24-3 94:4 | 24-5 | 24:6 | 24:2 | 23°6 |-23:9 | 24-1 
Hydrogen 2:3 27 2:8 2°6 2:7 2°6 2-4 2°4 
*‘ Tf these results are compared with each other, there can be no right to 
say that Hirtenberg gun-cotton alters by keeping. They agree as far with 
each other as analyses of the same material usually do. It is to be regretted, 
on this as on many other accounts, that during the last twelve years such 
analyses were not frequently repeated. If the opponents of gun-cotton, in 
performing an adverse experiment, heat the substance in a test-tube up to 
100° C., and holding litmus-paper over it, deduce from redness of the latter 
that gun-cotton changes after long keeping, they merely prove thereby that 
gun-cotton changes at 100°C. Of an explosive compound, it can only be 
required that it shall not deteriorate within certain limits of temperature,—a 
requisition amply fulfilled by Lenk’s gun-cotton. 
‘Some varieties of gun-cotton, if enclosed together with litmus-paper in a 
tube, often manifest an acid reaction at ordinary temperature. This may 
arise from various causes. There may exist, for example, free acids. These 
acids may be the result of nitrogen partially oxidized, and may result from 
imperfectly worked cotton. This assumption granted, the phenomenon is 
explained, and the cause easily avoided. It may arise from decomposition of 
the gun-cotton, atmospheric dampness having brought about a partial recon- 
stitution of the cellulose.” 
(4) “ But some specimens of Lenk’s cotton do not even yield traces of de- 
composition. 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 sub- 
jected to all the various influences of dew, rain, and sun, day and night con- 
tinuously. 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 trinitro-cellulose, as 
the following Table makes apparent :— 
Calculated. Found. 
Carboniorived hal ssataath. 88 2452. ostionwat 24-4 
Hydrogen. |. «asad Sri 14 att 23. fo tabi. ak 28 
(5) “ Temperature at which Gun-cotton ignites.—The rejection of gun-cotton, 
in consequence of the changeable nature or explosive quality of the material 
at low temperatures, is so thoroughly and decidedly contradicted in the Re- 
