64: ALIMENTATION". 



place of that which has become effete, the mineral substances 

 are deposited with them ; and the organic principles, as they 

 become effete, or are transformed into excrementitious sub- 

 stances and discharged from the body, are always thrown 

 off in connection with the mineral substances which enter 

 into their composition. This constant discharge of inorganic 

 principles, forming as they do an essential part of the organ- 

 ism, necessitates their introduction with the food, in order 

 to maintain the normal constitution of the parts. As these 

 principles are as necessary to the proper constitution of the 

 body as any other, they must be considered as belonging to 

 the class of alimentary substances. This conclusion is inevi- 

 table, if alimentation be regarded as the supply of material 

 for the regeneration of the organism. 



Water. This should be placed at the head of the list 

 of inorganic alimentary principles. It constitutes the great- 

 est part of the fluids which are used as drink ; l but is seldom, 

 if ever, taken in a pure state, all potable, waters containing 

 numerous inorganic salts in solution. A consideration of its 

 functions as a solvent, and in giving the proper consist- 

 ence to parts, belongs to the physiological chemistry of the 

 organism. 2 It is always to be remembered, however, that 

 water forms a part of all the organic nitrogenized principles, 

 and is indispensable to the manifestation of their vital prop- 

 erties. It exists, therefore, in all the ' animal and vegetable 

 nitrogenized elements of food, and serves as the vehicle for 

 the introduction of all the inorganic salts and the soluble 

 non-nitrogenized alimentary principles. 



Chloride of Sodium. Of all saline substances, chloride 

 of sodium is the one most widely distributed in the animal 

 and vegetable kingdom. It exists in all varieties of food. 



1 Water, with the substances which it holds in solution and with which it is 

 combined, will be taken up more fully under the head of drinks. 

 3 See vol. i., p. 30 et seq. 



