FOODS. 153 



When overheated, avoid drinking much cold water. Re- 

 peatedly rinse the mouth with cool water, and swallow very 

 little. This is the way trainers manage a horse at a race, 

 and it is sensible to treat a man as carefully. 



Salts. Salts include many substances besides common 

 salt. They aid in the solution of various substances during 

 digestion and in other processes. We cannot live without 

 salt. 



Lime in the form of calcium phosphate and calcium car- 

 bonate is essential, especially in the bones and teeth. Iron 

 is associated with hemoglobin. 



Necessity of a Mixed Diet. Our experience, together 

 with the results of the experiments on animals, teaches 

 that we could not live long if fed on any one class of 

 foodstuffs alone. We must take a representative of each 

 of the groups. We have noticed that most of our foods 

 already contain more than one foodstuff. We so combine 

 them as to get suitable proportions. Thus we eat bread 

 and butter (a small amount of fat with a large quantity of 

 starch and a little gluten), meat and potato, crackers and 

 cheese, pork and beans, egg on toast, bread and milk, rice 

 and fowl, macaroni and cheese ; they " go well together " 

 chiefly because they are complementary. 



Disadvantages of a One-sided Diet. In order to get 

 enough nitrogen from bread alone, one would have to eat 

 about four pounds a day ; meanwhile twice as much car- 

 bon as is needed would be taken, thus throwing an undue 

 amount of work upon the digestive organs. Again, one 

 would need to consume about six pounds of meat to get the 

 requisite amount of carbon, and six times as much nitro- 

 gen as is needed would be taken ; to get rid of this extra 

 nitrogen would severely tax the kidneys and liver. 



