286 Mr. F. A. Abel on some of the applicatio?is [May 23, 



mentally the advantages possessed by the fulminate of mercury 

 over other fulminates, and over detonating mixtures, as a means of 

 firing small-arras ; and the necessity of rendering the decomposition 

 of the fulminate of mercury more gradual, and the resulting heat 

 more intense, by employing in admixture with it chlorate of potassa 

 or saltpetre.* The cost of fulminate of mercury had been con- 

 siderably reduced by the beneficial measure lately introduced by 

 Government, with reference to spirits of wine ; a result of the im- 

 portant suggestion of Professors Graham, Hofmann, and Redwood, 

 to mix the spirits of wine required for the arts and scientific pur- 

 poses with a small quantity of wood-spirits, insufficient to interfere 

 with its applications, but sufficient to preclude the possibility of its 

 being rendered palatable. Alcohol was employed in large quantities 

 for moistening explosive or highly combustible compositions which 

 were subjected to successive blows, as in the preparation of fuses. 

 The introduction of methylated spirits for these purposes had proved 

 a matter of great economy, not only in consequence of its compara- 

 tively low price, but also because it was no longer impossible, as 

 formerly, to ensure the exclusive application by the workmen of the 

 alcohol to its legitimate use. 



Mr. Abel next directed attention to some points of interest in 

 connection with the manufacture of gunpowder. The analysis of 

 a number of different specimens of powder, obtained daring the 

 war from various English and continental sources, had shown that 

 no important difference, as regards composition, existed between 

 powders varying very much in their most important properties. A 

 comparison was instituted between the methods of manufacture 

 adopted in England, France, Prussia, and Belgium, and between 

 the general properties of the powders of these countries. It was 

 found that the very powerful pressure to which the powder made at 

 Waltham Abbey was submitted, rendered it superior to any other 

 powder, in its uniformity and its power of resisting the effects of trans- 

 port, and of exposure to the atmosphere ; while, on the other hand, 

 it was inferior to continental powders in its inflammability. In the 

 employment of Waltham Abbey-powder in large charges, a con- 

 siderable proportion always escaped ignition, while the combustion 

 of the softer continental powder, under the same circumstances, was 

 always, comparatively speaking, perfect. The rapidity with which 

 the grain of a soft powder was destroyed by transport, and the 

 injurious influence of moLsture upon it, led to the conclusion that, 

 with respect to durability, the advantages were in favour of the 

 hard pressed powder, but that the softer powder was superior from 



* In France the preference was given to nitre, as the vapours resulting from 

 the decomposition of chlorate of potassa were liable to excite a corrosive action 

 on the nipple of the gun. In England, nitre had been abandoned in favour of 

 chlorate of potassa, since percussion caps, the priming of which contained the 

 former salt, had been found, after having been in store for some time, to have 

 become so much corroded as to be unserviceable. 



