268 Professor Davy’s Account of 
were converted into the new compound ; but only 3.02 grains of this substance could 
be collected from the filter, instead of about 3.48 grains: the loss on the filter, how- 
ever, was nearly equivalent to the deficiency, as was ascertained by comparing the 
weight of the dried filter, with another, equal in every respect, and placed under 
sunilar circumstances.* 
The preceding experiments afford the nearest approximations I could obtain, to the 
composition of the new compound, by that mode of operating. The difficulty of 
gaining uniform results, by converting Howard’s compound into the new compound, 
arises partly from the facility with which the new compound, when first formed, is 
redissolved by an excess of nitrate of silver ; and partly from its being to a certain 
limited extent, either dissolved by water, or partially decomposed by it. 
In converting the new compound into chloride of silver, a given weight of it, (well 
dried, ) was put into a platina crucible ; a little pure water was added, and then some 
pure muriatic acid of moderate strength ; a considerable action took place, hydrocy- 
anic acid appeared to be evolved, and after digestion for a short time, water was put 
into a crucible, the chloride was thrown on a filter, washed, dried, collected and fused 
in a platina capsule, previously counterpoised in a very delicate balance. Operating in 
this manner, I found, that on fusing the chloride in the capsule it was of a dark colour, 
having some small specks in it like charcoal. On exposing the capsule to a full red heat, 
the dark coloured chloride seemed to undergo ebullition ; it evolved gas, and gradually 
assumed a yellowish white colour. It now lost no weight on being heated to redness, 
and no part of it appeared to be reduced. In one experiment, thus conducted, 6 
grains of the new compound afforded 4.70 grains, and in another experiment, 6 grains 
yielded 4.82 grains of fused chloride of silver. Now, if the mean of these experi- 
ments is taken, 6 grains will afford 4.76 grains, and 100 grains of the new com- 
pound, will yield 79.33 grains of chloride, equivalent to 54,73 grains of metallic 
silver, or 58.44 grains of oxide of silver. These results, so nearly correspond with 
those derived from a different method of examination already noticed, that [ venture 
to regard the new fulminating silver, as a compound of one proportion of oxide of 
silver 118. and two proportions of fulminic acid 84, or of 
58.42 oxide of silver 
41.58 fulminic acid 
100.00 
I made a number of comparative experiments on the two fulminating silvers, all of 
* I have since found, that in decomposing Howard’s compound, by Zine, &c. another compound of sil- 
ver is formed. It is of a dull white colour, but changes on exposure to light. It does not explode by heat, 
but ignites and burns for an instant, leaving a brown substance, which by a strong heat is converted 
into silver. When decomposed over mercury, the products were oxide of silver, carbonic acid gas, and 
carbonate of ammonia. This substance may partly account far the loss in the above experiments ; 
but its quantity seems too minute to affect the accuracy of the statements made. 
