INORGANIC ALIMENTARY SUBSTANCES. 175 



Sodium Chloride. Of all saline substances, sodium chloride is the one 

 most widely distributed in the animal and the vegetable kingdoms. It exists 

 in all varieties of food ; but the quantity which is taken in combination with 

 other matters is usually insufficient for the purposes of the economy, and 

 common salt is generally added to certain articles of food, as a condiment, 

 when it improves their flavor, promotes the secretion of certain of the digest- 

 ive fluids and meets a nutritive demand on the part of the system. Experi- 

 ments and observations have shown that a deficiency of sodium chloride in the 

 food has an unfavorable influence on the general processes of nutrition. 



Calcium Phosphate. This is almost as common a constituent of vegetable 

 and animal food as sodium chloride. It is seldom taken except in combina- 

 tion, particularly with nitrogenized alimentary matters. Its importance in 

 alimentation has been experimentally demonstrated, it having been shown 

 that in animals deprived as completely as possible of this salt, the nutrition 

 of the body, particularly in parts which contain it in considerable quantity, 

 as the bones, is seriously affected. 



Iron. Haemaglobine, the coloring matter of the blood, contains, inti- 

 mately united with organic matter, a certain proportion of iron. Examples 

 of simple anaemia, which are frequently met with in practice and are almost 

 always relieved in a short time by the administration of iron, are proof of 

 the importance of this substance in alimentation. The quantity of iron 

 which is discharged from the body is very slight, only a trace being discov- 

 erable in the urine. A small quantity of iron is frequently introduced in 

 solution in the water taken as drink, and it is a constant constituent of milk 

 and eggs. When its supply in the food is insufficient, it is necessary, in 

 order to restore the normal processes of nutrition, to administer it in some 

 form, until its proportion in the organism shall have reached the proper 

 standard. 



It is hardly necessary even to enumerate the other inorganic alimentary 

 substances, as nearly all are in a state of such intimate combination with 

 nitrogenized matters that they may be regarded as part of their substance. 

 Suffice it to say, that all the inorganic matters which exist as constituents of 

 the organism are found in the food. That these are essential to nutrition, 

 can not be doubted ; but it is evident that by themselves they are incapable 

 of supporting life, as they can not be converted into either nitrogenized or 

 non-nitrogenized organic matters. 



Alcohol. All distilled and fermented liquors and wines contain a greater 

 or less proportion of alcohol. As these are so generally used as beverages, 

 and as the effects of their excessive use are so serious, the influence of alco- 

 hol upon the organism has become one of the most important questions con- 

 nected with alimentation. Some alcoholic beverages influence the functions 

 solely through the alcohol which they contain ; while others, as beer and por- 

 ter, with a comparatively small proportion of alcohol, contain a considerable 

 quantity of solid matter. 



Alcohol (C a II 8 0), from its composition, is to be classed with the non-nitro- 

 genized substances. It has already been stated that sugar and fat are essen- 



