?PHYSiCAL AND LITERARY. df 



fubftances feems to be fufpended till they are 

 a^ain feparated from one another. 



Crude lime was therefore confidered as a 

 peculiar' acrid earth rendered mild by its 

 union with fixed air : and quick-lime as the 

 fame earth, in which, by having feparated 

 the air, we difcover that acrimony 'or* attra- 

 dion for water, for animal, vegetable, and 

 for inflammable fubftances. 



That the calcarious earths really lofe a 

 large quantity of air when they are burnt to 

 quick-lime, feems fufficiently proved by an 

 experiment of Mr. Margraaf^, aii exceeding- 

 ly accurate and judicious Chemift. He fub- 

 jeifled eight oMnctsoi' ojieocolla to diftilla- 

 tion in an earthen retort, finiiliing his procefs 

 with the mod violent fire of a reverberatory, 

 and caught in the receiver only two drams of 

 water, which by its fmell and properties 

 fhewed itfelf to be flightly alkaline. He does 

 not tell us the weight of the ojieocolla re- 

 maining in the retort, and only fays, that it 

 was converted into quick-lime j but as no cal- 

 carious earth can be converted into quick-lime, 

 or bear the heat which he applied without 

 Lofing above a third of its weight, we may 



fafely 



f Mem. de TAcad. de Berlin, an. 1748, p. 57. 



