130 j Assemble 



made, those substances were found present in sufficient quantity^ 

 and some other matter was wanting. 



A cubic foot of calcareous or silicious sandy soil weighs 



nearly 112 pounds, 



A soil in which clay and sand are equal, 96 do 



A soil which we consider arable, 86 do 



A soil abounding in clay, , 76 do 



A rich mould or garden soil, 72 do 



A mucli or peat soil, 55 do 



The weight of all soils decreases as clay increases, and continue 

 the decrease as the vegetable matter increases. Dense soils are 

 much less injured by the tramping of cattle and passage of wheels 

 over it than others, and retain their warmth longer after sunset. 

 A peat, o-r muck soil, will cool more in one hour than a pipe-clay 

 in two and a halt, and a sand in three and a quarter hours All 

 soils resist the plow more when wet than when dry, and an iron 

 plow less than a wooden one. A wet sandy soil resists the plow 

 equal to from 4 to 5 lbs. to the square foot, a gardt^n soil from 5 

 to 7 lbs., and a clay from 7 to 30 lbs., because it adheres to the 

 instrument more than any other soil. A good agricultural soil 

 should possess the power of drinking moisture from the dewy air 

 at night, which in dry seasons is of immense importance. I once 

 dried two hundred and fifty pounds of a very rich and fertile 

 garden soil, and exposed it to a moist atmos[)here fur one hour, 

 W'hen it weighed 2541 pounds, having absorbed in that short time 

 4| pounds of water. I then dried 250 pounds of coarse sand, and 

 exposed it lo the same atmospheric influence for an hour j when 

 weighed again it had absorbed only two pounds. This shows that 

 rich soils possess the valuable property of absorbing moisture 

 much more rapidly than poor. I desired to discover the power 

 of the same land to retain water, and for this purpose placed 100 

 pound in a tin vessel, and poured water on gradually until it 

 began to drop from the bottom, then weighed it, and found it 

 had increased 23 pounds. In this way I determined what land 

 would be improved by draining, what by irrigation, which are 

 best adapted to wheat, and which to corn, the subject before lis 



