CAPTAIN NOBLE AND ME. E. A. ABEL ON EIEED GUNPOWDEB, 
83 
of 6804 grains (440*9 grms.) of R. L. G. powder, which occupied 90 per cent, of total 
space in the chamber (Experiment 68): — 
Residue. 
Carbonate. 
Sulphate. 
Hyposulphite. 
Sulphide. 
Sulphur. 
Top portion . 
. 52*15 
7*69 
I7*I 4 
6*03 
4*88 
Lower portion 
. 67*75 
7*44 
4‘34 
7*30 
10*09 
Similar results were obtained by the separate examination of the top part of other* 
residues. Again, one of the small drops or buttons of the fused solid products which 
have been mentioned as being generally found upon the firing-plug in the cylinder (the 
residue of this particular experiment contained a somewhat considerable proportion of 
sulphide) was found to be quite free from sulphide, but contained hyposulphite. 
Lastly, a mixture of potassium carbonate and sulphide, after exposure in a crucible for 
30 minutes to a temperature of about 1700° C. in a Siemens furnace (in which the 
atmosphere consisted of carbonic anhydride, carbonic oxide, and nitrogen), was found 
to contain a small quantity of hyposulphite. The production of this substance, as the 
result of a secondary reaction, should, however, be rendered evident by a marked 
increase in the proportion of carbonic oxide in all instances in which a large amount 
of hyposulphite was found ; and this was certainly not the case, as will be seen by a 
comparison of the results of Experiments 8 and 7, 3 and 11, 19 and 17. 
Potassium. 
Experiment. 
Carbonic 
anhydride. 
Carbonic 
oxide. 
carbonate. 
sulphate. 
-A. 
hyposulphite. 
sulphide. 
8. Pebble 
. *2577 
•0519 
•3115* 
•0843 
•H63 
•0416 
7. Pebble 
. *2517 
’°575 
*3216 
•0768 
•0208 
•1011 
3. R.L.G. 
. *2504 
'°393 
*3128 
*1378 
•O329 
•0547 
11. R.L.G. 
. *2624 
•0360 
•2819 
*1324 
* I 393 
•0117 
19. F.G. . 
. *2678 
*°339 
•2615 
*1268 
•1666 
•0196 
17. F. G. . 
. *2512 
•0416 
•3454 
*1409 
•0308 
•0298 
It appears, therefore, that the formation of hyposulphite cannot be regarded as due 
to the occurrence of a secondary reaction between carbonic anhydride or carbonate and 
sulphide produced upon the explosion of gunpowder, but that it must be formed either 
during the primary reaction of the powder-constituents on each other (in other words, 
by the direct oxidizing action of saltpetre), or by an oxidation of sulphide by liberated 
oxygen following immediately upon the first change (which results in the formation of 
a large quantity of sulphide), and being regulated in extent by the amount of oxygen 
liberated at the moment of explosion. The view that hyposulphite must be, at any 
rate in part, due to the oxidation of sulphide formed in the first instance, appears to 
be supported by the circumstance that the proportion of the latter in the powder-residues 
is as variable as that of the hyposulphite, and is generally low when the hyposulphite 
is high. Moreover in our experiments the proportion of sulphate is, except possibly 
in a few instances, apparently not affected by the amount of hyposulphite formed. On 
the other hand, the amount of sulphur which exists either in combination with iron 
