COMBINATION OF MERCURY 



J X. The Quantity of A ] cid contained in 

 white Mercurial Precipitate. 



MANY circumflances tend to prove that the 

 white mercurial precipitate contains lefs acid 

 than the corrofwe. It is, in the firfl place, of 

 more difficult folution, of a milder nature, and 

 receives a darker colour from lime water and fpi- 

 rit of ial ammoniac. According to their fcvcral 

 conditions it is varioufly aileclcd by acids and by 

 mercury ; which is by no means furpriiing, as all 

 mercurial falts, differing from corrofive fubli- 

 mute and fweet mercury, and holding a place 

 between them, are commonly exprefled under 

 the name of white mercurial precipitate. 



S xxi. Adulteration of white Mercurial Pre- 

 cipitate, 



IT. 5s not uncommon to meet with this fait in 

 a (late of adulteration. This is fometimesefiedcd 

 by a mixture of white lead ; for the difcovery of 

 which fraud DoiCe hasinllitutcd an experiment*. 

 I le di reels a fourth part of a lixivial fait to be mix- 

 ed with the mercurial precipitate, the whole to be 

 expofed to the fire, until the mercury riles un- 

 der the appearance of fmoke. If lead is found 

 in the crucible, the fraud is beyond a doubt ; if 



not, 



* Laboratory laid open. 



