Mr. E. Howard on a new fulminating Mercury. 237 



In addition to the other singular properties of the fulminating 

 mercury, it may be observed, that two ounces inflamed in the 

 open air, seem to produce a report much louder than when the 

 same quantity is exploded in a gun capable of resisting its 

 action. Mr. Cruickshank, who made some of the powder, by 

 my process, remarked that it would not inflame gunpowder. 

 In consequence of which, we spread a mixture of coarse and 

 fine grained gunpowder upon a parcel of the mercurial powder ; 

 and, after the inflammation of the latter, we collected most, if 

 not all, of the grains of gunpowder. Can this extraordinary fact 

 be explained by the rapidity of the combustion of fulminating 

 mercury? or is it to be supposed, (as gunpowder will not 

 explode at the temperature at which mercury is thrown into 

 vapour,) that sufficient caloric is not extricated during this 

 combustion ? 



From the late opportunity I have had of conversing with 

 Mr. Cruickshank, I find that he has made many accurate 

 experiments on gunpowder; and he has permitted me to state,, 

 * that the matter which remains after the explosion of gun- 

 " powder, consists of potash united with a small proportion of 

 " carbonic acid, sulphate of potash, a very small quantity of 

 " sulphuret of potash, and unconsumed charcoal. That 100 

 " grains of good gunpowder yield about 53 grains of this resi- 

 " duum, of which three are charcoal. That it is extremely 

 " deliquescent, and, when exposed to the air, soon absorbs 

 " moisture sufficient to dissolve a part of the alkali ; in conse- 

 " quence of which, the charcoal becomes exposed, and the 

 " whole assumes a black or very dark colour." Mr. Cruick- 

 shank likewise informs me, that after the combustion of good 

 gunpowder under mercury, no water is ever perceptible. 



