or l^otmttiott of ftjctnefo 13 



pear lets extravagant, if you confidcr 

 what happens in the preparation of 

 Quick- filver precipitated perfe. For 

 there, running Mercury, being put 

 into a conveniently (haped Glafs, is 

 expofed to a moderate fire for a con- 

 fiderable rime : ( For I have fome* 

 times found fix or feven weeks to be 

 too (hort a one.) In this degree of 

 fire the parts are varioufly tumbled, 

 and made many of them to afcend* 

 till convening into drops on the fides 

 of the glafs, their weight carries them 

 down again 5 but at length, after 

 many mutual occurfions, if not alio 

 attritions, fome of the parts begin to 

 ftick together in the form of a red 

 powder, and then more and more 

 Mercurial particles are fattened to it, 

 till at length all, or by much the 

 greater part of the Mercury, is re- 

 duced into the like Precipitate? which, 

 by this cohefion of the parts, being 

 grown more fixt, will not with the 

 fame degree of Heat be made to rife 

 and circulate, as the Mercury would 

 before 3 and yet, as I eliewhere note, 



t have 



