106 AMERICAN MANURES. 



phoric acid ? sulphuric acid, lime, magnesia, 

 oxide of iron, potash, soda, chlorine, oxygen, 

 hydrogen, and nitrogen, with a certain amount 

 of decaying vegetable matter, the farmer can 

 see why the soils given as fertile are so, and 

 why the others are sterile. As a key to the 

 amounts of the different substances contained in 

 the soil of an acre of land, the farmer should 

 know that every inch in depth of an acre of 

 average soils, weighs about one hundred tons; 

 hence a soil ten inches deep would weigh just 

 one thousand tons. 



The following is an analysis of a very fertile 

 soil, in the vicinity of the Zuyder Zee, in Holland, 

 as given by the celebrated chemist Mulder. 



Insoluble sand with Alumina 57'646 



Soluble Silica 2-340 



Alumina, soluble 1'830 



Peroxide of Iron 9-039 



Protoxide of Iron 0-350 



Lime 4-092 



Magnesia 0-130 



Potash 1-026 



Soda 1-972 



Ammonia 0-060 



Phosphoric Acid 0*466 



Sulphuric Acid.... 0-896 



Carbonic Acid 6*085 



Chlorine 1-240 



Humus, or mould, vegetable re- j 



mains and water chemically com- > 12-000 



bined J 



Loss.. 0-828 



Total 100-000 



