WITH THE MARINE ACID. 325 



arc interchanged, which conftitute cinnabar and 

 kma cornea. 



v. II. What if tbe Importance of the nitrous 

 Acid tn the Preparations of mercurial Sub- 

 limate ? 



As it is exceedingly difficult To to fubdue 

 mercury by triturution \vitli common fait, as to 

 deflroy its fluidity; and as even when this la- 

 bour is mod fuccefsful, the metal is Rill railed 

 too quickly by the heat; the nitrous acid has 

 been employed by feveral chemitls to reilrain 

 the volatility of the mercury, and to render it 

 more diviiiblc, and culler to be mixed. But this 

 is not the folc reufon tor adding the nitrous acid. 

 Some people pour it upon the mercury while it 

 i.s triturating with the fait, in order to corrode 

 the metal, and contribute to its extinction. O- 

 thcrs again, following the flop* of J. II. Curdi- 

 luccio, ufe the nitrous folution of mercury ; in- 

 to three pounds of which he ordeis a few hand- 

 fids of fults to be thrown, the iluid mixture to 

 be gradually exiiccatcd, and the rcfiduum to 

 be diltiiied in a retort *. In this procefs, a white 

 precipitate of mercury, (of which we fliull prc- 

 ix:ntly give a fuller account,) is produced, which 

 is railed by the fire in the form of a milder fub- 

 limatc. Some alfo pour the muriatic acid upon 

 X 3 the 



* R. MindcrcTJ Ks -icgfaruncy. 



