ME. ABEL’S EESEAECHES ON GUN-COTTON. 
225 
Table YII. (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. 
129 
The same as expe- 
riment 128, bu' 
washed repeat- 
edly in distiller 
water. 
grms. 
65 
20 hours in 
3 days. 
4 hours 
Not observed.. 
The temperature began to rise on 
the 1st day after 4 hours’ heating. 
It rose to 109° in 30 minutes, 
and remained stationary till the 
close of the day. On the 2nd day 
it rose gradually to 1 04 0 , and after 
remaining stationary for some 
time, gradually returned to 100°. 
No change observed on the 3rd 
day. 
130 
The same as expe- 
riment 129, bu 
very carefully 
washed in dis- 
tilled water. 
6-5 
2 h 30 m 
After 2 hours’ heating the tempera- 
ture rose, and had reached 103° 
by the close of the 3rd hour, and 
109° in another hour. On the 
2nd day the thermometer rose to 
102° in 30 minutes after com- 
mencing, and reached 106° in 15 
minutes more. It soon after- 
wards began to fall, and had re- 
turned to 100° by the close of the 
6th hour. No rise of tempera- 
ture occurred on the 3rd and 4th 
days. 
4 days. 
131 
Medium-size yarn, 
6-5 
21 hours in 
ftO per cent.... 
The temperature began to increase 
slightly at the close of the 3rd 
hour ; the maximum temperature 
1 10° was reached in 3 h 50 m . The 
thermometer then soon began to 
fall, and after nearly 7 hours’ total 
heating, had returned to 100°. 
No change of temperature on the 
2nd and 3rd days. 
Waltham. 
3 days. 
132 
Same as experiment 
1 3 1 , but carefully 
washed in dis- 
tilled water. 
6-5 
21 hours in 
lh30 ra 
31 per cent.... 
The temperature rose gradually 
above 100° after 1-J hour’s heat- 
ing. In 2 h 50 m it had reached 
111°; the thermometer fell slowly 
soon afterwards ; in 3 h 30 m from 
the commencement it had re- 
turned to 105°, and indicated 
100° in 6 hours after commence- 
ment. No change on the 2nd and 
3rd days. 
3 days. 
133 
Same as experiment 
131, but extracted 
with dilute acid 
and afterwards 
carefully washed. 
65 
21 hours in 
1 hour 
34 - 6 per cent.. 
The temperature began to rise before 
expiration of the 1st hour. In 
2 h 15 m it had reached 110° ; the 
thermometer then fell and re- 
turned to 100° by the close of the 
1st day’s experiment. 
3 days. 
134 
Medium -size yarn, 
another sample. 
6-5 
20 hours in 
3 days. 
2 hours 
20'3 per cent.. 
After 2 hours' heating the tempera- 
ture rose gradually and reached 
1 1 1 ° -5 at the expi ration of the 3rd 
hour. It then returned slowly to 
100° by the close of the 1st day’s 
heating. No change on the 2nd 
and 3rd day. 
135 
Sameas experiment 
134, but repeat- 
edly soaked and 
washed in dis- 
tilled water. 
6-5 
20 hours in 
lh 45 m 
Not recorded.. 
The temperature began to rise after 
the lapse of l h 40 m ; in 3 h 7 m it 
had reached 118°-5. In another 
hour it had fallen to 103°-5, and 
it returned to 100° by the close 
of the 1st day. No subsequent 
rise. 
3 days. 
Other observations. 
Nitrous vapours were very abun- 
dant after 5 hours’ heating du- 
ring 1 hour. The gun-cotton as- 
sumed a brown colour. The 
aqueous extract contained nitric 
acid, a little oxalic acid, and re- 
duced cupric salts abundantly. 
The insoluble portion was feebly 
explosive, and almost perfectly 
soluble in ether and alcohol. 
The substance had contracted con- 
siderably, was brown and pulve- 
rulent, soluble to a considerable 
extent in water, the solution ex- 
hibiting the usual reactions. 
The gun-cotton became dissolved 
on the 2nd day. At the conclu- 
sion it was brown and pulveru- 
lent, partially soluble in water ; 
the solution contained a minute 
quantity of oxalic acid, and re- 
duced cupric salts abundantly. 
The residue dissolved in ether 
and alcohol, furnishing a horny 
brittle substance, which defla- 
grated when heated. 
The substance had sustained the 
same alteration as in the preced- 
ing experiment, but was soluble 
to a larger extent in water. 
The colour of the product was 
deeper than the two preceding, 
and a very large proportion was 
soluble in water. 
Both samples had assumed a buff 
colour, were strongly acid and 
friable. The unwashed gun- 
cotton furnished the largest 
proportion soluble in water. 
The aqueous solutions furnish- 
ed the usual reactions. 
