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ift. He tells us that by flow folution of loo grs. of ihe fpar in 

 acids he found the lofs of weight to amount to 34 grs. only, though 

 by applying a flrong heat he found it to amount to 45. Hence he 

 concludes that in folution the fixed air fingly was expelled, but 

 that both fixed air and water were expelled by heat. Now to ob- 

 tain a flow folution in acid he muft have ufed a very dilute acid, 

 and have employed a very narrow mouthed vefTel. In this cafe 

 much of the fixed air is reabforbed by the folution, as daily expe- 

 rience fliews, and thus muft have prevented his perceiving the real 

 quantity of the air expelled from its combination with the earth. 



Again Lavoifier computes 100 grs. of chalk to have loft about 

 34 grs. of air by folution in nitrous acid ; but this lofs he inferred 

 not from a dired trial, but from the weight of the volume of air 

 found by comparifon with that of common air, calculated accord- 

 ing to Mr. De Luc's rules. This concurrence muft undoubtedly 

 have confirmed Mr. Bergman in this erroneous eftimation. 



So alfo in natural lime-ftones, the quantity of fixed air being 

 found that of the lime is in the above proportion, except in a few 

 cafes where magnefia exifts in them or the lime not faturated. 

 Hence 100 grains lime take up 8r,8i of fixed air, but 100 grains 

 of it are precipitated by fomewhat lefs. Klapreth eftimates the 

 proportion in this at 4 of fixed air to 5 of lime. And 100 grains 

 fixed air faturate 122,24 of lime, but would precipitate 125. 



Se£fton 



