198 ESSAYS AND OBSERVATIONS 



I indeed expe<fted to fee a much larger quan- 

 tity of fediment produced from the lime, on 

 account of the air which water conftantly con- 

 tains, and with a view to know whether wa- 

 ter retains its air when fully faturated with 

 lime, a lime-water was made as ftrong as pof- 

 fible ; four ounces of which were placed un- 

 der the receiver of an air-pump, together with 

 four ounces of common water in a vial of the 

 farne fize ; and, upon exhaufling the recei- 

 ver, without heating the vials, the air arofe 

 from each in nearly the fame quantity : from 

 whence it is evident, that the air, which 

 quick-lime attrads, is of a different kind from 

 that which is mixed with water. And that 

 it is alfo different from common elaftic air, is 

 fufficiently proved by daily experience ; for 

 lime-water, which foon attrads air, and forms 

 a crufl when expoled in open and (hallow vef- 

 fels, may be preferved, for any time, in bot- 

 tles which are but llightly corked, or clofed 

 in fuch a manner as would allow free accefs 

 to elaftic air, were a vacuum formed in the 

 bottle. Quick-lime therefore does not attract 

 air when in its moft ordinary form, but is ca- 

 pable of being joined to one particular fpecies 

 only, which is difperfed thro' the atmofphere, 



either 



