[ i«o ] 



3"- In his 30th experiment he employed mere potters clay; 

 the grain grew tolerably well the firft ye:ir, but perifhed the fe- 

 cond ; on tlie third it flourilh.ed moft. It is hard to draw any 

 fpecific conclufion from this experiment, for it is plain that if the 

 texture were not much loofer than that of clay, the corn could 

 not grow at all, as was the cafe in his 6th and 8th experiments, 

 already mentioned, and as Mr. Haffenfraz, who repeated this ex- 

 periment, obferved. Rain water might however fupply a fmall 

 quantity of calx fufficient for a fmall produce of corn. 



I PASS over his experiments on old mortar, as the three earths 

 were evidently contained in it, though in unknown propor- 

 tions. 



Soils on the declivitv of hills ought to be more retentive of 

 water than thofe on plains, as is evident. 



CHAP. III. 



To determine the Compojition of a Soil. 



jmo. jjj (jry weather, when the foil is not overmoift nor dry, 

 let a furface of 16 inches fquare be cut through to the depth of 

 8 inches ; this may be effeded by a right angled fpade formed 

 for this particular purpofe. Of the parallelopiped thus dug up 

 the two inches next the furface fhould be cut off to get rid of 

 the grafs and the greater part of the roots, we fhall then have a 

 folid 6 inches long and 1 6 fquare at the end = 96 cubic inches. 



Let 



