CHAPTER V. 



CHEMISTRY OF THE HUMAN BODY. 



Ultimate and Organic Elements. 



l.fBy the chemical composition of the. body, is meant 

 those ultimate elements of which it is made ;^ such asjbxygen, 

 carbon, hydrogen, and azote.j By the organic composition, 

 we mean the proximate elements, which are formed out of 

 these by the power of the living principle ; such as albumen, 

 Jibrin, gelatine$&c. 



S.^The ultimate elements of animal matter have been 

 divided into non-metallic, and metallic substances ; the former 

 consisting of oxygen, hydrogen, carbon, azote, phosphorus, 

 sulphur, chlorine, and fluorine ; the latter, 1, the bases of the 

 alkalies, viz., potassium, sodium, and calcium ; 2, the bases 

 of the earths, magnesium, silicium, and aluminum ; 3, the 

 ponderous metals, iron, manganese, and copper.} 



Of the first class, or the non-metallic substances, oxygen, 

 hydrogen, carbon and azote exist in much the largest pro- 

 portion, and are in fact the only essential elements of animal 

 matter. 



3.| All the solids and fluids of the body contain oxygen., 

 It is essential to all the proximate elements. United with 

 hydrogen, it forms water, which is calculated to constitute 

 nine-tenths of the whole weight of the body. In union with 

 carbon, it forms carbonic acid, which exists in the blood, and 

 is thrown out by the lungs and skin. 



3. Oxygen forms with phosphorus, phosphoric acid, which 

 with lime constitutes the earthy portion of the bones ; it also 

 exists in some of the secretions. In union with their metalic 

 bases, it forms potash, soda, and lime. It also is a consti- 



