33* COMBINATION OF MERCURY 



the authors of the London Pharmacopoeia direcl 

 an addition to be made of one twelfth of corro- 

 flve fublimate. 



The pure and uncombincd nitrous acid, with 

 which Junkenius orders the mixture of mercu- 

 ry, vitriol, and common fall, to be moiltcned, is 

 applicable to the fame purpofc. But he pro- 

 pofcd likcwife another procefs, viz. equal weights 

 of common fait and vitriol are to be calcined 

 together, fomc of the mixture to be fpreud on 

 the bottom of a veflcl, and then mercury filter- 

 ed through leather ; and thus alternately to be 

 placed layers of mercury and of the mixed falts. 

 As much nitrous acid then, as is fuflicient to 

 moiilcn the mafs, is poured upon it ; the liquid 

 is expelled by diftillation, and the dry matter 

 remaining is fublimcd *. 



When vitriulutcd tartar is added to a nitrous 

 folution of mercury, a powder is precipitated, 

 which, when cxpofed to the fire with common 

 fait, very eafily produces corrofivc fublimate. 

 Stahl fecms to have mentioned this mode of 

 proceeding, but in obfcure language f. Pott 

 has explained it with more prccilion J ; and has 

 proved with the pcrfcvcrencc of Baume, that 

 vitriolic acid can be feparatcd, by means of the 

 nitrous, from the falts to which it adheres. Ac- 

 cordingly, 



* Lex Pharm. Chcm. 1699. 



f Von lialzcn, 1738. <"';* 



1 Mifccll. Ctrolin. t. v. 



