COMBINATION OF MERCURY 



been known for fomc centuries part, but we have 

 no information refpecling the peribn by whom 

 it is invented. 



} xvm. Modes of Preparation. 



THE moft common method is to pour a quan- 

 tity of fait- water into a nitrous iblution of mercu- 

 ry after which the mixture becomes ilreakcd and 

 cloudy, and a white mucilaginous matter gra- 

 dually fubfidcs to the bottom of the veflel. 

 The water is added as long as any thing is pre- 

 cipitated ; afterwards when the white mafs is 

 collected, the clear liquor is poured oil* the rc- 

 fiduum is well wafhcd in pure water, and being 

 then inclofed in bibulous paper is dried either 

 in the air , or over the fire. The fire employ- 

 ed fhould however be very moderate, leail by 

 too great heat the powder acquire a yellow co- 

 lour -j-. 



In this procefs a double Reparation or decom- 

 polition of the i.igrcdients takes place. The 

 mercury is feparated from the nitrous acid, and 

 unite* with the acid of the common fait, form- 

 ing a fait but little foluble in water; and the ni- 

 trous acid quits the mercury, and with the mine- 

 ral alkali of the common fait, produces cubic 



nitre. 



* Barchufen Elem. Chcm. 1712. 

 f MietiinCollca. Chcra. Lcydcnf. 



