28 flDfttie ^ec&amcal 0)*fgine 



air, but will require a not defpicstble 

 degree of fire to fublimeit. 



Of thefe femivolatile CompofitL- 

 ons of Salt I have made, and elfe- 

 where mentioned, others, which I 

 (hall not here repeat, but paffeon to 

 other Inftances pertinent to our pre- 

 fcnt defign. 



I lately mentioned, that the Vola- 

 tility of the fpirits of Nitre may be 

 very much abated, by bringing them 

 to coagulate into Cryftalls with 

 particles of corroded Silvers but I 

 ftiall now add, that I gueffed, and by 

 trial found, that thefe Nitrous fpi- 

 rits may be mad£ much more fixt by 

 the addition of the Spirit of Salt, 

 which, if it be good, will of it felf 

 fmoak in the Air. For, having difc 

 (blveda convenient quantity of Cry- 

 ftalls of Silver in diftilled water, and 

 precipitated them,not with a Solution 

 of Salt, but the Spirit of Salts the 

 phlegm being abftra&ed, and fome 

 few of the loofer faline particles* 

 though the remaining raaflfe were 

 preft with a violent fire that kept 



