j 6 ^Tbe Principles of . Part I. 



FROM this experiment it appears, that 

 the falts of this foil are of the volatile al- 

 kaline kind ; and that thefe falts naturally 

 exift in it, as they rife with a fmall degree 

 of heat. From this likewife we have an- 

 other proof of oil being contained in this 

 foil, as it tinged the firft water with a yel- 

 lowifh colour, gave it a burnt fmell, and 

 was plainly to be difcovered in the fecond 

 floating about in a filamentous way. 



SECT. IV. 



Of -the day foil. 



THE clay foil is very different from 

 the former ; and as it is a compofi- 

 tion of clay with a mixture of the former 

 foil, we mail inquire into the properties of 

 clay. 



THE diftinguiihing and char act eriftical 

 property of this body is, that having al- 

 ready got a certain quantity of moifture, it 



refills, 



