

v\ 



294 Analyfts of the Air. 



Thus in Experiment 7 3 we fee by the vaft 

 quantity of air there is found in Tartar, 

 that tho' it contains the other principles of 

 vegetables, yet air with fome volatile Salt 

 feems to make up a confiderable part of its 

 composition ; which air, when by the action 

 of fire it is more firmly united with the 

 earth, and acid fulphureous particles, requires 

 a more intenfe degree of heat, to extricate 

 it from thofe adhering fubftances, as we find 

 in the diftillation of Sal Tartar, Exper. 74. 



which Air and volatile Salt are moft readily 

 feparated by fermentation. 



And by Experiment 72, plenty of air arifes 

 alfo from Nitre, at the fame time that the 

 acid fpirit is feparated from it by the action 

 of fire. 



We find alfo by Experiment 7 1 , that 

 fome air is by the fame means obtained 

 from common fea Salt, tho' not in fo great 

 plenty, nor fo eafily, as from Tartar and Ni- 

 tre, it being a more fixt body, by reafon of 

 the fulphur which abounds in it* neither 

 is it fo eafily charged in animal bodies, as 

 other Salts are, yet fince it fertilizes ground^ 

 it muft needs be changed by vegetables. 







There 



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