FERTILITY OF DIFFERENT SOILS. 13 



the common view respecting the nutritive office of 

 humic acid, in a manner so clear and conclusive 

 that it is difficult to conceive how it could have 

 been so generally adopted. 



Fertile land produces carbon in the form of 

 wood, hay, grain, and other kinds of growth, 

 the masses of which differ in a remarkable 

 degree. 



2650 Ibs. Hessian of firs, pines, beeches, &c. grow 

 as wood upon 40,000 square feet of forest-land with 

 an average soil. The same superficies yields 2500 

 Ibs. Hessian of hay. 



A similar surface of corn-land gives from 18,000 

 to 20,000 Ibs. Hessian of beet-root, or 800 Ibs. 

 Hessian of rye, and 1780 Ibs. Hessian of straw, 

 160 sheaves of 14 Ibs. Hessian each, in all, 2580 

 Ibs. Hessian. 



One hundred parts of dry fir-wood contain 38 

 parts of carbon ; therefore, 2650 Ibs. contain 1007 

 Ibs. Hessian of carbon. 



One hundred parts of hay*, dried in .air, contain 

 44*31 parts carbon. Accordingly, 2500 Ibs. of hay 

 contain 1008 Ibs. Hessian of carbon. 



Beet-roots contain from 89 to 89*5 parts water, 

 and from 10*5 to 11 parts solid matter, which 

 consists of from 8 to 9 per cent, sugar, and from 2 



* 100 parts of hay, dried at 100 C. (212 F.) and burned with oxide 

 of copper in a stream of oxygen gas, yielded 51-93 water, 165'8 carbonic 

 acid, and 6'82 of ashes. This gives 45-87 carbon, 5-76 hydrogen, 

 31-55 oxygen, and 6'82 ashes. Hay, dried in the air, loses 1 1-2 p. c. 

 water at 100 C. (212 F.}.Dr. Will. 



