230 Intelligence and Miscellaneous Articles. 



enough for the charge of a musket, within an exhausted receiver, to 

 a wire intensely ignited by a galvanic discharge. The grains did 

 not take fire instantly, probably because the vapour evolved pre- 

 vented actual contact ; and when ignition did ensue, it extended only 

 to the production of a feeble flash. On examination, it was found 

 that a portion of the powder had escaped inflammation. 



In the next place, a like weight of gunpowder was consolidated 

 into a cylinder by intense pressure. Thus prepared and ignited, by 

 contact with an incandescent wire in the exhausted receiver, more 

 than half of the cylinder remained unconsumed. 



A much larger cylinder of the same mixture, similarly consolidated, 

 placed at the bottom of an iron pot, four inches in diameter and 

 twelve inches in depth, on being touched by the end of an iron rod 

 reddened in the fire, burnt at first like a squib, but towards the last 

 was dissipated with an activity in some degree explosive, probably 

 in consequence of the pressure created by the reaction of the gaseous 

 current generated by its own deflagration. 



The want of confinement, which is thus capable of lessening the 

 explosiveness of gunpowder, of which the constituents are intimately 

 intermingled, is still more enfeebling, where analogous reagents are 

 ignited together without admixture or comminution. Under these 

 circumstances, the reagents are made to recede from each other by 

 the generation of that vapour or gas, to the evolution of which, under 

 confinement, the capability of exploding is due. Thus sundered, they 

 are chilled by radiation, so that the temperature requisite to sustain 

 and communicate ignition is not supported. Moreover, the rapidity 

 of reaction being as the multiplication of the points of contact, and 

 these being fewer as the substances are less divided and intermingled, 

 the deflagration takes place in detail, instead of having that simul- 

 taneousness which is indispensable to render it explosive. 



In addition to the ideas above-mentioned as having been conveyed 

 in Dr. Hare's letter to Hays, it was urged also that his inference as 

 to the explosion of water with incandescent nitre being attributable to 

 a reaction analogous to that represented as taking place when potas- 

 sium is burnt with the oxide of hydrogen, was supported by the fact, 

 that at a white heat the base of nitre spontaneously abandons its acid, 

 while from water it cannot be separated by any temperature. Conse- 

 quently, the presentation of substances, consisting of carbon, hydro- 

 gen, and oxygen, by yielding water to the base, could not but be 

 productive of a result analogous to that which results from the pre- 

 sentation of sulphur and carbon. 



The only obstacle is as follows : — Substances containing hydrogen 

 and oxygen, whether in the proportion for forming water, like sugar, 

 starch, gum and wood, or having an excess of hydrogen, like oils and 

 resins ; moreover, all the constituents of nitre, even the base, are 

 susceptible of the aeriform state at the temperature producible by the 

 reaction of nitre with them. But when kept together until that point 

 is attained, the explosive power must be fully equivalent to that of 

 gunpowder. The reagents are in a state analogous to that of two 

 gases extremely condensed. 



