and Detonating Matches. 141 



16.3 grains, being about one-third of a grain per cap. Treated 

 with hot water, it yielded 8.5 grains of soluble matter, of 

 which 7.0 grains were nitre, and 1.5 nitrate of mercury derived 

 from the ill-made fulminate. By boiling again in water, this 

 passed into a yellow subnitrate. 



. 7.2 Grains of insoluble matter were brushed off the dried 

 filter and heated with dilute muriatic acid. The solution 

 being thrown on a filter, this retained 1 grain of carbon and 

 sulphur, while 6.2 grains of fulminate of mercury passed 

 through in the state of a bichloride. The proportions of this 

 match-powder must have been, therefore, 8 grains of a kind of 

 gunpowder, and about 8 of indifferent fulminate of mercury ; 

 and yet it exploded very well : it obviously contained more 

 nitre than usually enters into gunpowder. 



The proportions deduced by the French commissioners from 

 their elaborate and able researches are 10 of fulminate, and 

 6 of pulverin (gunpowder meal). 



100 grains of fulminate triturated with a wooden muller on 

 marble, with 30 grains of water and 60 of gunpowder, arc 

 sufficient to mount four hundred detonating caps. 



In describing the formation of fulminating mercury, I 

 omitted a curious fact that lately occurred to me. Desirous 

 of moderating the reaction of the mixture, which had been 

 overheated, I added a little alcohol from time to time, till its 

 " quantity was increased by nearly one half. The fulminate being 

 washed, and laid out on the filtering paper in the air, when 

 nearly dry, minute brilliant points were observed to start up on 

 different parts of its surface, which, becoming larger, were 

 found to be globules of mercury. This metallization went 

 silently and slowly on till nearly one-half of the powder dis- 

 appeared. An ethereous hydro-carbonate was evidently the 

 agent in this unexpected reduction*. . 



* To the relative conservative powers of different gunpowders, my attention 

 was first drawn by my very intelligent friend, Major Moody, Commanding Royal 

 Engineer of the Government Gunpowder Works ; and through his co-operation I 

 hope to be able, in another paper, to prosecute this subject, so interesting in a 

 national point of view. 



London, September, 1830. 



