[ ryz J 



The fpecific gravity is not given, hut fhould not much exceed" 

 I fuppofe 1 600. Mufchenbrock found that of garden mould 1,630. 

 The carbonic matter was not known to Mr. Bergman. 



The proportion in a troy pound, fi^ppofing the quantity of 

 water and coal not to exceed loo grains, ftands thus, omitting, 

 fradions : 



Here we fee the quantity of calx much greater than in the 

 foil of Turin, where the fall of rain is greater; for in the drier 

 climates there is a neceffity to retain the rain, and the argill if 

 increafcd would retain it too long and too much ; and, befides, 

 enters very fparingly into the conftitution of plants. 



The following experiments were made by Mr. Tillet at Paris, 

 where the fall of rain amounts to 20 inches at an average. 



He filled with mixtures of different earths a number of pots- 

 twelve inches in diameter at the top, ten at bottom, and feven 

 or eight deep-, it appears alfo that they were fo porous as to 

 abforb moifture, and that they were perforated at the bottom;. 



thefe 



