ON THE APPLICATION OF GUN-COTTON TO WARLIKE PURPOSES. 11 
specimen of gun-cotton, were closely concordant; but those furnished by 
different specimens varied slightly. 
The following were the mean percentage results obtained :— 
Per cent. 
(a) From a specimen of gun-cotton prepared for cannon ...... 1:14 
(5) From a specimen of gun-cotton prepared for small arms and 
Peels iin Ura. teat oe apie egies Chahs Bete duin) 3 0:42 
(c) From aspecimen of gun-cotton prepared for blasting-purposes 1-90 
(This specimen was slightly discolored, made from a lower quality of 
cotton, and not so perfectly washed as (a) and (b).) 
The analysis of the ash furnished by the gun-cotton in these experiments, 
demonstrated the existence of some differences in the proportions of the 
several mineral constituents of the different specimens. The ash from (a) 
consisted of 
Silicic acid........ 0-71 per cent. in the cotton. 
WEG es Sas a ee ees 0:13 Y, re 
Marnedia” 2.53... % trace 
Oxide of iron...... trace 
PIKAINOR oc Sadie 0:25 35 Bd 
Sulphuric acid .... trace 
That furnished by specimen (4) consisted principally of lime; it contained 
besides traces of magnesia, oxide of iron, and alkalies, and only a small trace 
of silicic acid. 
The ash from (c) consisted of— 
Sand and clay ...... 0-75 per cent. in the cotton. 
Silicic acid, soluble .. 0°53 3 cf 
cal i 0-27 PP 7 
Ralies THR S25 0°30 me 5 
Magnesia ........ 
Oxide of iron oo... p traces. 
Sulphuric acid 
The ash was determined for comparison in a specimen of cotton obtained 
from the Austrian Works, which had been submitted to the preparatory 
purifying processes (treatment with carbonate of potassa and long-continued 
washing). The results obtained furnished a mean of 0-63 per cent. of ash, 
which consisted principally of lime and magnesia, and contained a small pro- 
portion of insoluble matter (clay and sand), traces of soluble silicic acid, and 
of alkalies, 
The above determinations and analyses of the ash in the gun-cotton and 
in the unconverted cotton, show that no result of the slightest practical im- 
portance, in the direction supposed to be aimed at, is obtained by the treat- 
ment with solution of soluble glass, to which the purified gun-cotton is sub- 
mitted, according to the Austrian system of manufacture. 
It is evident that, by the washing in running water for five or six hours, 
and subsequent rinsing of each skein, after the treatment with silicate of 
soda, the proportion of the latter which had in the first instance been 
introduced into the cotton is again extracted, only traces being retained by 
the cotton, besides a very small proportion of silica in the form of pulveru- 
lent silicate of lime, resulting from the decomposition of the soluble glass 
by the lime-salts in the spring- or river-water. It will be observed that, in 
specimen (6) of gun-cotton, the proportion of non-volatile constituents is 
actually even less than that found in the purified but unconverted cotton,—a 
