26 CHEMICAL COMPOSITION OF HUMAN BODY. 



of chemical purity. All the fluids and tissues of the body 

 appear to consist, chemically speaking, of mixtures of 

 several of these principles, together with saline matters. 

 Thus, for example, a piece of muscular flesh would yield 

 fibrin, albumen, gelatin, fatty matters, salts of soda, 

 potash, lime, magnesia, iron, and other substances, such as 

 kreatin, which appear passing from the organic towards 

 the inorganic state. This mixture of substances may be 

 explained in some measure by the existence of many 

 different structures or tissues in the muscles ; the gelatin 

 may be referred principally to the cellular tissue between 

 the fibres, the fatty matter to the adipose tissue in the 

 same position, and part of the albumen to the blood and 

 the fluid by which the tissue is kept moist. But, beyond 

 these general statements, little can be said of the mode in 

 which the chemical compounds are united to form an 

 organized structure ; or of how, in any organic body, the 

 several incidental substances are combined with those 

 which are essential. 



The inorganic matters which exist as such in the human 

 body are various. 



Water forms a large proportion, probably more than 

 two-thirds of the weight of the whole body. 



Phosphorus occurs in combination, as in the tribasic 

 phosphate of soda in the blood and saliva, the super- 

 phosphates of the muscles and urine, the basic phosphates 

 of lime and magnesia in the bones and teeth. 



Sulphur is present chiefly in the sulphocyanide of potas- 

 sium of the saliva, and in the sulphates of the urine and 

 sweat. 



A very small quantity of silica exists, according to 

 Berzelius, in the urine, and, according to others, in the 

 blood. Traces of it have also been found in bones, in hair, 

 and in some other parts of the body. 



Chlorine is abundant in combination with sodium, potas- 

 sium, and other bases in all parts, fluid as well as solid, of 



