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temperature higher. The more it is mephitized the more alkali it 

 appears to faturate, but afterwards the fait extradls oxygen from 

 the air; when melted it alfo lofes part of its oxygen and of its 

 water of compofition, but in time feems to regain them. 



-According to Wenzel, 83,5 parts tartarin were faturated by 

 90 of his ftrongeft acid, and the compound heated to rednefs 

 weighed 173,5. 



Then 100 grains tartarin fhould take up 107,78 of his flrongeft 

 acid (= 87,51 of my real acid) and afford 207,78 of dry nitre. 



And 100 parts nitre contain, by his account, 48,13 of alkali, 

 and 51,87 of his ftrongeft acid, = 42,1 18 of my real acid. 



AccORniNC to Bergman, 49 parts tartarin afford, when fa- 

 turated with nitrous acid, 100 parts nitre, confequently 100 parts 

 tartarin would afford 204, 



Lavosier*= allows nearly 49 per cent, of alkali and 51 of acid 

 (including water) to roo grains of nitre. 



Berthollet, in the Memoirs of the Royal Academy for 1781, 

 obferves, that 480 parts of nitre afford, by diftiilation, 714 cubic 

 inches of fomewhat impure oxygen air, then 100 parts of nitre 



would 



• P. 157 of the Englifti Edition of his Elements of Chymiftry. 



