353 COMBINATION OF MEKCURY 



rained by the means of reagents, unlefs nitrated 

 mercury mould be rendered turbid by the acid 

 poured upon it. As I fufpedled that this ap- 

 pearance might be owing to a quantity of hete- 

 rogeneous matter mixed with the folution, I en- 

 deavoured to feparate it by adding diilblved al- 

 kali, but to little purpofe ; the cloudy (late of 

 the acid was in no way to be removed, until all 

 the mercury was fir (I precipitated. 



When a confidcrahlc quantity of muriatic a- 

 cid is poured iuddenly upon a nitrous folution of 

 mercury, inilead of a white mercurial precipitate 

 we obtain a corrollve mercury caiily ibluble in 

 water. Monnct, therefore, very prudently ad- 

 vifes in the preparation of white mercurial pre- 

 cipitate, that both the folution of the mercury, 

 and the muriatic acid to be employed, fliould be 

 well diluted, and the mixture of them made 

 gradually and with caution *. 



The precipitate ought to be wafted in as much 

 water as will be futlicient to difljlve all the cu- 

 bic nitre combined with it. On the other hand, 

 if too much water is poured upon the precipi- 

 tate, and fullered to remain any length of time, 

 it is again eaiily diflblvedf . White mercurial 

 precipitate wafted in warm water, is called by 

 Mayern manna mercunnlis \. 



Plummer 



* Afta Acad. R. Suec. a. 1770. 



f Eflay for a reformation of the London PHarm. 



m. iiuiule. 



