CHEMISTRY OF THE HUMAN BODY. 219 



But iron, among the mineral constituents of the 

 body, does not stand alone in its important relation-, 

 ship. The metals exist combined with other bodies, 

 or they are locked up in the form of salts, which 

 are vital to the economy. There are five pounds 

 of phosphate of lime, one of carbonate of lime, 

 three ounces of fluoride of calcium, three and a 

 half ounces of common salt, all of which have im- 

 portant offices to fill. Not one of them must be 

 allowed to fall in quantity below the normal stand- 

 ard. If the lime fails, the bones give way ; if salt 

 is withheld, the blood suffers, and digestion is im- 

 paired ; if phosphorus is sparingly furnished, the 

 mind is weakened, and the tendency is towards 

 idiocy. 



Whence do we obtain these extraordinary metals 

 and mineral substances which are diffused through 

 the body ? It is certain that among the dishes 

 found upon our tables, none contain phosphorus, 

 lime, iron, or magnesium, in their isolated condi- 

 tion. In the food we daily consume these minerals 

 are found, and they constitute a part of the mate- 

 rials of its structure. A pound of wheat, of which 

 we make our bread, holds a quarter of an ounce of 

 mineral substances ; a pound of potatoes contains 

 the eighth of an ounce ; cabbages, lettuce, apples, 

 pears, strawberries, etc., also containpconsiderable 

 quantities. Beef and other meats contain about 



