414 MM. Liebig and Gay-Lussac on [June, 



ought to be procured, but this third remains in solution in the 

 nitric acid, and in the washings. 



Fulminate of silver does not detonate alone at a temperature 

 of 212° Fahr. nor even at 266°; but it must not be exposed to 

 the slightest percussion between two hard bodies, even when it 

 is in water. Consequently wooden stirrers only should be 

 employed, instead of glass ones, and the capsules on which it is 

 put should be placed upon several folds of paper ; it is prudent 

 also to remove it only with bits of paper; for the detonation of a 

 few grains only of this matter occurring on the hand would infal- 

 libly occasion its loss. 



We ascertained, by operating upon very small quantities of 

 fulminate, that it might be rubbed on a porcelain capsule with a 

 cork or the finger, after having mixed it with forty times its 

 weight of peroxide of copper, and that it did not detonate when 

 exposed to the action of heat; we employed this method of deter- 

 mining what were the proportions of carbon and azote in the 

 fulminate of silver. Two decigrammes (grs. 3-0888) of this salt 

 mixed with four times its weight of oxide of copper, and heated 

 in a glass tube produced a gaseous mixture, the last portions of 

 which, after the expulsion of the common air, were composed of 

 two parts by volume of carbonic acid gas and one volume of 

 azote ; consequently in the fulminate of silver, or rather in the 

 fulminic acid, the carbon and the azote are in the same propor- 

 tions as in cyanogen. 



Fulminate of silver containing two portions of oxide of silver, 

 one of which serves as a base to the salt, and the other appears 

 to be a constituent of fulminic acid, we endeavoured to deter- 

 mine each with precision. Their total quantity is easily obtained 

 by decomposing fulminate of silver by muriatic acid, and evapo- 

 ration to dryness ; towards the end of the operation, a little nitric 

 acid is to be added in order to decompose a small quantity of 

 muriate of ammonia, which is formed during the evaporation, 

 and which is derived from the decomposition of an acid, which 

 we shall presently mention. 



2*266 parts of fulminate of silver, thus decomposed, yielded 

 2*171 of chloride of silver. Reducing; this chloride to oxide of 

 sdver, 100 of fulminate contain 77-511 of oxide of silver; in a 

 second experiment 1*060 of fulminate yielded 1*016 of chloride 

 of silver, or 100 of fulminate contain 77*545 of oxide of silver. 



By taking the mean of these two experiments, 100 of fulmi- 

 nate of silver contain 77*528 of oxide of silver, or 



Silver 72*187 



Oxygen 5-341 



77*528 



We suppose that all the silver is in the state of oxide, and it 

 will be seen that this supposition is extremely probable. 



