550 
DR. H. DEBUS ON THE CHEMICAL THEORY OE GUNPOWDER. 
no constituents of the saltpetre occur in them, they may he regarded as merely 
accessory products not directly concerned in the explosion. 
As the composition of the Austrian service powders does not differ much from that 
of the powders of Waltham Abbey, it will be interesting to contrast the results of 
Karolyi with those obtained by Noble and Abel. 
Remarkable differences will be observed if equation (I.), page 545 is compared with 
the composition of the products of combustion observed by Karolyi and represented 
by means of chemical symbols on page 549. Equation (I.), as well as Karolyi’s 
results, are calculated for quantities of powder containing 16 mols. KN0 3 . 
Noble and Abel, according to equation (I.), found about a quarter of the potassium 
of the decomposed saltpetre as potassic sulphide, whereas in Karolyi’s experiments the 
sum of the potassium in the hyposulphite, and in the sulphide of the products of com¬ 
bustion of cannon powder amounted to only -^g-th, and in that of the rifle powder only 
to -^-th of the potassium of the saltpetre of the exploded powder. It seems to follow 
that the production of such small quantities of potassic hyposulphite and sulphide 
cannot be the direct result of the chief reactions of the explosion. Karolyi obtained 
much more potassic sulphate and less potassic carbonate than the English chemists; a 
considerable quantity of the carbon of his powders remained unconsumed, whilst in Noble 
and Abel’s experiments, as a rule, every trace of this element was burnt, although the 
English powders contain somewhat more carbon than the Austrian. Similar differences 
occur between the results obtained with the gaseous products. The gases obtained by 
Karolyi were combustible, those of Noble and Abel were not. The gases from the 
Austria,n powders contained more hydrogen and marsh gas and less sulphuretted 
hydrogen than those from the mixtures of Waltham Abbey. 
Hydrogen. 
Marsh gas. 
Sulphuretted hydrogen 
Mean percentage by volume. 
Austrian. 
Waltham Abbey. 
6*41 
2*50 
2*86 
0-31 
076 
2*56 
Karolyi inclosed his powders in a thin brass cylinder hermetically closed, and 
ignited the charge by means of a galvanic current. As soon as the tension of the 
gases developed by the combustion had reached a certain magnitude the metal 
cylinder exploded, and its contents were scattered against the cold sides of the 
exhausted 60-pounder shell. Thus the combustion of the powder was interrupted 
before its completion. The correctness of this view is rendered apparent if the effect 
is considered which would have followed if the products of Karolyi had remained 
in contact for some time at a red heat. The free carbon and hydrogen, and the 
constituents of the marsh gas would have been burnt at the expense of the oxygen 
-of the potassic sulphate; the quantity of the latter would have been diminished and 
