1824.] Fulminate of Silver. 419 



Two atoms of silver, 



Two atoms of oxygen combined with the silver, 



Two atoms of oxygen combined with the elements of the 



fulminic acid. 



rp c f 2 atoms of azote, 



Two atoms of cyanogen = | 4 atQms of carbo ' n> 



It evidently follows from this analysis, that fulminate of silver 

 does not contain sufficient oxygen to convert its carbon into 

 carbonic acid. The examination of the residuum left by the 

 fulminate of silver after decomposition by oxide of copper, in 

 which copper is found in its metallic state, gives an incontro- 

 vertible proof of this ; but it would not be easy to determine by 

 this method the quantity of oxygen really deficient. 



It would have been important to have ascertained the products 

 of the immediate detonation of the fulminate of silver; and we 

 did not fail to make some experiments with this intention ; but 

 we were compelled to abandon it on account of the fracture of 

 the vessels, which took place with a very small quantity of fulmi- 

 nate, and by the danger inseparable from experiments of this 

 kind. On the other hand, it appeared very easy to determine 

 the products of the decomposition of the fulminate of silver by 

 heat, after having mixed it with substances incapable of supply- 

 ing it with oxygen : that which at first appeared preferable to us 

 was glass reduced to an impalpable powder; but every time that 

 we endeavoured to mix it with the fulminate, detonation took 

 place, and prudence compelled us to give up this method. 



By employing chloride of potassium instead of glass, the 

 mixture may be rubbed by the finger, or with a cork, without 

 danger, after having mixed it as intimately as possible with a 

 small slip of card. 



A portion of fulminate of silver weighing 6* 131 grains (0*397 

 gramme), decomposed by this process, produced 1 1*929 cubic 

 inches of gas; with oxide of copper, this same quantity of fulmi- 

 nate would have given 36*81 cubic inches. The 11*929 cubic 

 inches of gas contained no oxide of carbon, and were composed 

 merely of azote and carbonic acid. Now, according to this 

 composition, if all the oxygen of the fulminate had been employed 

 to form carbonic acid, and the azote had been disengaged with it, 

 and recollecting that in the complete combustion of the fulminate 

 by oxide of copper, the azote constitutes one-third of the whole 

 volume, and the carbonic acid two-thirds, there should have been 

 obtained 



Azote = {- of 36*81 = 12*27 



Carbonic acid = I of 36*81* 12*27 



24 54 



• Wc say one-third of ,'j6 # 8l, because, in our experiment, only one-half the quan- 

 tity of carbonic acid could be formed that would result from the complete combustion of 

 the carbon. 



2 e2 



