340 ESSAYS and OBSERVATIONS 



"wilh an oppofite fait. But art can again 

 produce it to view, and reftore all its 

 former powers. If, in this procefs, five or 

 fix ounces of fpir. nitri^ or aqua forth, 

 were employed in the beginning, and, 

 after the laft ftep, the liquor is diluted 

 with fome more water, (trained through 

 brown paper, fully fatiated with the al- 

 caline liquor or fait, and then llowly e- 

 vaporated and chryftallized : There will 

 be procured a fait perfe(5lly refembling 

 common falt-petre, in the fhape of the 

 chryflals, explofive quality, and other 

 marks. This fadtitious falt-petre then 

 may be employed in place of the com- 

 mon ; and I diftilled fome ounces of a 

 fait, made much in the fame way (for I 

 imagine the intermediate fteps will make 

 no alteration) with oil of vitriol, in Glau- 

 ber's manner, and obtained a (Irong 

 fmoakjng fiiirit, which anfwers all the 

 characters of Glauber's fpirit of nitre, 

 Und diflbWes the fame bodies ; and there- 

 fore may run through the fame courfe, 

 over and over, without any change, un- 

 lefs that it may be gradually wafted, fome 



part 



