i 9 6 Analyfis of the Air. 



feems to make up a confiderable part of its 

 compofition ; 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 fepa- 

 rated by fermentation. 



And by Experiment 72. plenty of air arifes 

 alio from Nitre, at the fame time that the 

 acid fpirit is feparated from it by the action 

 of fire. 



We find alfo by Experiment 71. that fome 

 air is by the fame means obtained from com- 

 mon Sea-falt, tho' not in fo great plenty, nor 

 {0 eafily, as from Tartar and Nitre \ it being 

 a more fixt body, by reafon of the fulphur 

 which abounds in it; neither is it io eafily 

 changed in animal bodies, as other Salts are; 

 yet, fince it fertilizes ground, it muft needs be 

 changed by vegetables. 



There is good reafon alio to iufpecl, that 

 thefe acid (pints are not wholly free from 

 air-particles, notwithftanding there were no 

 elaflick ones produced, when they were put 

 into a brisk motion, by the action of fire in 

 Experiment 75. which might be cccafioned 



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