AMERICAN 



QUARTERLY JOURNAL 



OF 



AGRICULTURE AND SCIENCE. 



Vol. I. APRIL, 1845. No, 2. 



FOOD OF ANIMALS. 



BT THOMAS HUN, M. D. 



We find in nature two classes of bodies. The one compre* 

 hends inorganic substances, which may be simple, or composed of 

 two, or even three or four elements, united in such a way that by 

 ordinary chemical processes they may be analyzed, and again re- 

 produced by the combination of their elements. 



There is another class of bodies called organic, which are only 

 found in the vegetable or animal kingdom. They are never simple, 

 but are always composed of at least three, and sometimes of four 

 elements, and the elements are united in such a way, that though 

 the chemist can analyze these substances, he cannot reproduce them 

 by bringing together the elements of which they are formed. Or- 

 ganic matters, or proximate principles^ as they are called, are form- 

 ed only in the laboratory of the living plant, under conditions 

 which the chemist cannot imitate. 



The elements of which proximate principles are composed, are 

 carbon, oxygen, hydrogen and nitrogen. The three first are pre- 

 sent in all, the last in only some of them. 



On this is founded a distinction of the highest importance in 

 animal and vegetable physiology, namely, into uon-nitrogenized 

 and nitrogenized proximate principles. 



VOL. I. — NO. II. A 



