224 
ME. ABEL’S EESEAECHES ON GUN-COTTON. 
Table VII. (continued.) 
No. of 
experi- 
ment. 
Description of 
gun-cotton. 
Quan- 
tity Total expo- 
em- sure to 100° C. 
ployed. 
Interval be- 
tween first ex- 
posure and 
first signs of 
decom- 
position. 
124* 
The same as in ex- 
periment 122. 
16 hours in 
3 days. 
None observed 
Loss of weight 
sustained by 
the 
gun-cotton. 
None sustain- 
ed. 
Temperature observations. 
No increase of temperature indi- 
cated. 
125 The same as in ex- 6'5 
periment 122. 
22 hours in 
4 days. 
7 hours 
1 4 per c. after 
3rd day, 4'5 
per c. after 
4th day, 
total loss 
18 '5 per c. 
No rise of temperature on the 1st 
day. After 1 hour’s heating on the 
2nd day, the thermometer indi- 
cated 101°, and remained station- 
ary throughout the day. On the 
3rd day the thermometer rose to 
104° in 1 hour, but had fallen 
again to 100° in 15 minutes ; no 
further change occurred up to 
termination of the experiment. 
126 
127+ 
128 
/ The same as ex- 
periment 122, 
I but washed re- 
peatedly in 
distilled water. 
This treat- 
J ment not only 
| extracted the 
alkali, but se- 
parated much 
of the earthy 
carbonates at- 
tached to the 
fibre. 
Coarse yarn, Wal- 
tham, impreg- 
nated with 0-5 
per cent, of sodic 
carbonate. 
65 
6-5 
6-5 
lh 10 m 
50 minutes 
Not observed.. 
After 45 minutes’ heating the tem- 
perature rose rapidly; 116° was 
indicated shortly before the sam- 
ple exploded. 
22 hours in 
4 days. 
10 hours 
At the close of the 1 st hour’s heating 
the temperature rose rapidly. In 
10 minutes it had reached 113°, 
and in 5 minutes more it was 
118°; the gun-cotton exploded 
almost immediately afterwards. 
The first rise in temperature was 
observed after 3 hours’ heating 
on the 3rd day. The thermo- 
meter rose gradually to 1 10°, but 
soon began to fall again, and had 
returned to 100° before the close 
of the 3rd day. No change oc- 
curred on the 4th day. 
Other observations. 
It was observed about 1 hour after 
commencing the experiment that 
a very small quantity of water 
had penetrated into the flask 
through the cork, which had been 
accidentally immersed in the 
water of the bath for a short time. 
The gun-cotton remained per- 
fectly unchanged ; it was dried 
at the close of the experiment, 
and found to have sustained no 
loss in weight. 
The(nitrous-acid vapours were only 
faint up to the rise of tempera- 
ture on the 3rd day, and were 
never abundant. The colour of 
the gun-cotton was not altered. 
It had an acid reaction and 
slightly pungent odour after the 
treatment ; its explosiveness did 
not appear diminished. The 
aqueous extract gave a faint in- 
dication of nitric acid, did not 
reduce cupric salts, nor furnish 
a precipitate with calcic chloride. 
The solubility of the gun-cotton 
in ether and alcohol had notably 
increased. 
The results of these two experi- 
ments should be compared with 
those obtainedin the preceding 
experiment, and with those 
furnished in experiment 29 
Tablel. by 6 5 grms. of the same 
! sample of gun-cotton, which 
[ had not been impregnated with 
alkali, nor submitted to the 
extra-washing process. 
Nitrous acid was abundantly evolv- 
ed for a short time on the 3rd 
day. The gun-cotton after the 
experiment had a pale brownish 
colour, but the small portion sur- 
rounding the upper part of the 
thermometer had become black- 
ened and hard, in consequence 
of the destructive action exerted 
by the moisture charged with 
acid, which condensed upon the 
thermometer-stem and fell upon 
that part of the sample. The 
aqueous extract contained nitric 
acid, no oxalic acid, and reduced 
cupric salts slightly. The gun- 
cotton dissolved to a large extent 
in ether and alcohol. 
* This experiment furnished an important indication of the preservative effect of moisture. The gun-cotton was not wet but 
only thoroughly damp. 
t A third experiment, corresponding to these two, furnished precisely similar results. 
