66 ALIMENTATION. 



very slight; a trace only being discoverable 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 insuf- 

 ficient, it is necessary, in order to restore the processes of nu- 

 trition to their normal condition, to administer it in some 

 form, until its proportion in the organism reaches the proper 

 standard. 



It is hardly necessary even to enumerate the other inor- 

 ganic alimentary principles, as nearly all are in a state of 

 such intimate combination with nitrogenized principles that 

 they may be regarded as part of their substance. Suffice it 

 to say, that all the inorganic matters which exist in the or- 

 ganism as proximate principles are found in the food. That 

 these are essential to nutrition, cannot be doubted ; but it is 

 evident that by themselves they are incapable of supporting 

 life, as they cannot be converted into either the nitrogenized 

 or the non-nitrogenized proximate principles. 



