f 0f tf>e $ecttmt'ctf 



be too much or too little, the Expe* 

 yiment may mifcarry,) we may by a 

 gentle evaporation, and fometimes 

 without it, and that in a few minutes, 

 pjbtaib Cryftals, which 5 being dried 

 after they have been, if it be need- 

 full, freed from any adhering par* 

 tides, (not of their own nature,) will 

 have upon the tongue neither a (harp 

 nor an alkalizate taft, but that faint 

 and fcarce fenfible bitternefs that be- 

 longs to Salt- peter, if it be pure Salt- 

 peter 5 for the impure may perhaps 

 flrongly relifh of the common Salt 

 that is ufually contained in it. 



The like produ&ion of Salt-peter 

 we have fometimes made in far lefs 

 time, and fometimes indeed in a trice* 

 by fub'ftituting, in fteadof the fixed 

 Salt of Nitre, the faline parts of good 

 Pot-afhes^ carefully freed by folutiott 

 and filtration from the earthy and 

 feculent ones* 



? I have fometimes confidered^whe* 

 iher the Phtinomena of thefe two Ex* 

 perimentsmay not be explicated by 

 fuppofing them toarifeftomthenew 



mag- 



