CAPTAIN NOBLE AND ME. F. A. ABEL ON FIRED GUNPOWDER. 
65 
physical appearance, so in behaviour of the solid, when removed from the cylinder, there 
were considerable differences between the experiments. The deposit was transferred 
to thoroughly dried and warm bottles, and sealed up as rapidly as possible. In most 
cases, during the very short time that elapsed while the transference was being made, no 
apparent change took place ; but in some a great tendency to development of heat was 
apparent ; and in one instance, in which a portion of the deposit (exhibiting this 
tendency in a high degree) was kept exposed to the action of the air, the rise of tempe- 
rature was so great that the paper on which it was placed became charred, and the 
deposit itself changed colour with great rapidity, becoming a bright orange-yellow on 
the surface. 
This tendency to heating always disappeared when the deposit was confined in a bottle 
and fresh access of air excluded. 
The portion of the residue which could not be removed from the cylinder in a dry 
state was dissolved out with water, the solution being reserved for examination in well- 
closed bottles. 
D. ANALYSIS OF THE PRODUCTS OF EXPLOSION. 
1. Gaseous Products. 
The method pursued for the analysis of the gaseous products of explosion presented 
only one important point of difference from that pursued by Bunsen and Schischkoff. 
The volume of gas at command being more considerable than was the case in the inves- 
tigations of those chemists, it was found more convenient to have recourse to methods 
for determining the sulphuretted hydrogen differing from that which they adopted — 
namely, its estimation by oxidation of the sulphur in the ball of potassium hydrate 
employed for absorbing the carbonic anhydride and sulphuretted hydrogen together. 
In some instances the volume of this gas was ascertained by absorption with manganese 
balls, but generally the following indirect method was pursued. The combined volume 
of carbonic anhydride and sulphuretted hydrogen was determined in one portion of the 
gas by means of potassium hydrate ; another portion of gas was then treated with a 
small quantity of cupric sulphate, and the volume of carbonic anhydride determined in 
the gas thus freed from sulphuretted hydrogen. 
The following numerical data relating to the analysis of the gases obtained by the 
explosion of 190-5 grms. of R. L. G. gunpowder (of Waltham-Abbey manufacture) in 
five times its own space are given in illustration of the detailed result obtained : — 
I. 
Volume. 
Tempe- 
Pressure. 
Volume corrected 
rature. 
for temperature 
and pressure. 
1 . Original volume of gas . . . . 
144-4 
13-3 
0-7243 
99-80 
2. After absorption of C0 2 and SH 2 . 
78-2 
13-3 
0-6727 
.50-16 
3. After absorption of oxygen . . 
76-9 
14-4 
0-6795 
49-64 
MDCCCLXXV. 
K 
