THE DENSITY AND VOLUME-WEIGHT OF SOILS. 



II 



Such a surface is always therefore an indication of an ex- 

 tremely heavy soil, difficult to cultivate; yet embracing some 

 of the most highly and permanently productive lands known in 

 the United States, and in India, where the " regur " lands of 

 the Deccan are of this character; they have been cultivated 

 without fertilization for thousands of years. The subjoined 

 physical analyses of lands of such extreme character as to be 

 almost uncultivatable will serve to exemplify their physical 

 composition. 



PHYSICAL ANALYSES OF HEAVIEST CLAY SOILS. 



No 242 Miss. No. 643 Cal. 



I log-wallows 



soil. 



Jasper Co. 

 Mississippi. 



Black Adobe. 

 Contra Costa 



Co. 

 California. 



Weight of gravel over 1.2 mm. diameter 

 " " between 1.2 and i mm 



" " between i and 0.6 mm 



Fine earth 



83 

 i. ig 

 _97-9l 



IOO.OO 



FINE EARTH. 



It will be noted that in both these extremely heavy soils the sum of 

 the clay and finest sediments is a little over 83%. 



It should be stated that both these soils after being thoroughly 

 wetted become so adhesive that it is almost impossible to travel 

 over the tracts occupied by them, and that they are practically 

 almost untillable, being too adhesive when wet; yet if allowed 

 to dry to a certain extent ( varying within very narrow 

 limits) they turn up by the plow in large clods, which after a 



