214 
CAPTAIN NOBLE AND MR. F. A. ABEL ON FIRED GUNPOWDER. 
sample of sporting powder (Curtis and Harvey’s No. 6), and of mining powder, the 
following course of proceeding was adopted for the removal of the solid residue from 
the explosion-vessel, and its preparation for analysis :—Distilled water which had been 
freed from air by long-continued boiling, was siphoned into the explosion-vessel when 
the latter had cooled, so that air was never allowed to come into contact with the 
solid residue. When the cylinder was thus quite filled with water, it was closed, and 
set aside for sufficient time to allow the residue to dissolve completely. The solution 
was then decanted into bottles freed from oxygen, which were quite filled with the 
liquid, and carefully sealed up until required for analysis, in carrying out which the 
course already described was pursued. 
The products obtained by the first of these modifications of the ordinary course of 
procedure were submitted to partial examination, the chief object being to see to what 
extent the proportions of hyposulphite and sulphide varied in the upper and lower 
portions of the residue, and the extent to which they were affected by the great 
difference in the mode of treatment sustained by the different portions of one and the 
same residue. The proportion of hyposulphite was determined in every instance, and 
the products were also examined in all cases for sulphide. In the first experiment the 
exact proportion of this latter constituent was ascertained only in one of the three 
portions of the residue in which it existed ; it will be seen that one of the ground 
portions contained none. The sulphate was determined in all instances, and, in the 
second experiment, the proportions of carbonate existing in the upper and lower 
portions of the (unground) residue were ascertained. The analytical results obtained 
are given in the following table 
o o 
