Seel. VII. Agriculture and Vegetation. 95 



pears to have been deftroyed in moft 

 counties at once by fome general difafter 

 which affected it; the natural depofition 

 of foil from thefe waters has buried it fo 

 deep. 



Exp. 30. When water is poured on this 

 body, it fucks it in greedily, and fwells like 

 a fpunge ; becomes very foft, but does not 

 fall down like marl into a powder. It is 

 by means of this quality that all fhells, 

 whether they are laid on corrupted, or be- 

 come fo in the foil, make ground fo very 

 light and fpungy. 



I could difcover no fait in it, by the dif- 

 ferent trials which I made. It makes a 

 ftrong effervefcence with acids, and requires 

 fix times more of them to faturate it, than 

 what any of the marls which I have yet 

 met with do. 



IT affords on diftillation, like all animal 

 fubflances, a urinous alkaline fpirit, and an 

 oil of the heavy kind. 



WHEN 



