of a while Colour and a crystalline Appearance. 1 1 » 

 various experiments, which it s needless to detail, thai it i9 

 a combination of oxide of silver, ammonia, and a vegetable, 

 substance; a combination analogous, as we find, to that 

 which constitutes the fulminating mcrcuiy of Mr. Howard. 



We may obtain this combination, which I shall call efe- 

 tonating silver, to distinguish it from the fitlminatlng silver 

 of M.Bertholiet, by dissolvmg silver in pure nitric acid, :n\c\ 

 bypourinii- into the solution, while it is effecting, a sulHcient 

 quantity of rectified alcohol, or by pouring the alcohol uiio 

 a nitric' solution of silver, with a considerable excess ot^acid. 



In the first case we must slightly warm the nitric ^cid ia 

 which the silver has been put, until the solution begins to 

 take place, i. e. until the first bubbles begin to be perceived. 

 We must then remove it from the fire and inmiedialcly add 

 a sufficiency of alcohol, so that no nitrous vapours may be 

 liberated. The mixture of the two liquors takes place with 

 a disengagement of heat ; the effervescence immediately re- 

 commences, without disengagement of nitrons gas ; it gra- 

 dually increases, and there is liberated at the same time a 

 strong smell of nitrous ether. The liquor soon becomes 

 turbid, and we see deposited a white crystalline and very 

 dull powder, which must be separated, when it ceases to 

 fall down, and washed several times with small quantities 

 of water. 



When we employ the solution of silver ready made and 

 strongly acid, we must heat it slightly and afterwards add 

 the afcohol; the heat produced by the mixture, which gra- 

 dually takes place, soon determines a considerable ebulli- 

 tion, and the powder is suddenly deposited *. 



This powder has the following properties : 



It IS while and crystalline ; but this last appearance is va- 

 riable with respect to the volume and the lustre of the ciy- 

 stals. 



It changes a little in the light. It indauies with a sharp 

 detonation bv, heat, agitation, or long continued fnclioii. 



• It is ainio-t needless to observe, tliat the mixture of alcohol and watm 

 nitric acid is Dubjtct to many accidents, and \vc njust conse'iuently <>i>eiate 

 ii,)on very small (['.lantitier.. 



Vol. 29. No. IH. Nov. lb()7- H Simple 



