226 
MR. ABEL’S RESEARCHES ON GUN-COTTON. 
Table VII. (continued.) 
No. of 
experi- 
ment. 
Description of 
gun-cotton. 
Quan- 
tity 
em- 
ployed. 
Total expo- 
sure to 100° C. 
Interval be- 
tween first ex- 
posure and 
first signs of 
decom- 
position. 
Loss of weight 
sustained by 
the 
gun-cotton. 
Temperature observations. 
| 
Other observations. 
136 
Coarse yarn, “ sili- 
cated”. 
Coarse yarn, “ not 
grms. 
6-5 
22 hours in 
3 h 25 m 
24 per cent.... 
Alter 3 h 30 m the thermometer began 
The sample had sustained the usual 
137 
6-5 
4 days. 
1 hour, ex- 
30 minutes . . . 
Not observed.. 
to rise. In 4 hours it indicated 
107°, and in 4f hours 110°. It, 
soon afterwards began to fall, re- 
turning to 107° by the close of the 
5 th hour. On the 2nd day it rose 
to 104 o- 5 in 30 minutes, but soon 
fell again slowly to 100° after the 
lapse of 4 hours. No further 
change. 
The temperature began to rise in 35 
changes, but did not yield a very 
large proportion of soluble mat- 
ter to water. 
This sample was of the same date 
silicated”. 
ploded. 
minutes ; it reached 107° in 55 
minutes, rising very rapidly. 
of manufacture as the silicated 
specimen used in experiment 15. 
Table VIII. 
First indica- 
No. of 
experi- 
ment. 
Nature of 
gun-cotton. 
Quan- 
tity 
em- 
ployed. 
Duration of 
exposure to 
90° C. 
tion of decom- 
position after 
commence- 
ment of expe- 
weight. 
Other observations. 
riment. 
138 
Fine yarn, Wal- 
grms. 
8 - 5 
36 hours in 
26 hours ; 6th 
In 6 days ; 
A very small quantity of carbonic acid escaped from the flash on the 
2nd day ; on the 3rd day the quantity was a little more considerable. 
tham, impreg- 
6 days. 
day. 
2‘22 per c. 
nated with 0'5 
The temperature having accidentally risen to 95° on the 6th day, 
per cent, of sodic 
nitrous acid was for the first time disengaged. At close of the expe- 
carbonate. 
riment, the gun-cotton was perfectly white ; it had an acid reaction, 
but the strength of fibre and explosiveness were scarcely affected. 
139 
Coarse yarn, Wal- 
3 
77 hours in 
9 hours; very 
faint. 
In 6 days ; 
The nitrous vapours were never disengaged abundantly. The gun- 
tham, impreg- 
12 days. 
3-9 per cent. 
cotton became of a buff colour by the close of the experiment ; it 
nated with 04 
was friable and soluble to a considerable extent in water, and in ether 
per cent, of sodic 
carbonate. 
and alcohol. 
140 
Fine yarn, contain- 
2 
32 hours in 
30 hours; 6th 
In 6 days ; 
The nitrous vapours were never more than faint. The gun-cotton 
ing 0-5 per cent. 
6 days. 
day, very 
2-73 per c. 
furnished a slightly acid aqueous extract, in which neither nitric nor 
of sodic carbo- 
faint. 
oxalic acids could be detected, and which did not reduce cupric 
nate. 
salts. The solubility in ether and alcohol was scarcely affected. 
141 
Coarse yarn, con- 
2 
32 hours in 
15 hours ; 3rd 
In 6 days ; 
The gun-cotton was almost odourless, only very faintly acid, and exhi- 
taining 0-4 per 
6 days. 
day, very 
1T7 per c. 
bited no change in explosiveness or other properties. 
cent, of sodic car- 
bonate. 
faint. 
142 
Same as experi- 
ment 4, but re- 
4-5 
32 hours in 
1 hour 
In 6 days ; 
40-6 per e. 
Nitrous acid was abundantly evolved 1 hour after commencement of 
experiment. The gun-cotton became brown, friable, soluble to a 
6 days. 
peatedly washed 
in distilled water. 
considerable extent in water, and in ether and alcohol. 
143 
'Same as experi- 
2 
32 hours in 
3 hours. 
In 6 days ; 
The gun-cotton was strongly acid, and a small proportion was dis- 
ment 3, but re- 
peatedly washed 
indistilledwater. 
1 6 days. 
10 5 per c. 
solved in water, the solution reducing cupric salts ; the proportion 
soluble in ether and alcohol had considerably increased. 
It will be seen that, in the experiments instituted at 100° C., with very considerable 
quantities of the “alkalized” gun-cotton (experiments 122 and 123) seven and eight 
hours elapsed before any symptom of decomposition was observed, while in operating 
with similar quantities of ordinary gun-cotton (experiments 26 and 27) decomposition 
became manifest in two hours and four hours. A comparison of experiment 27 with 
experiments 122 and 123, also shows that when once the gun-cotton began to undergo 
