Foods and Cooking. 149 



better to heat the water twice nearly to the boiling point 

 than to boil once only. The first heating may start the 

 germs into more active life, causing them to sprout (so to 

 speak), and a second heating several hours later may easily 

 kill them ; whereas it has been proved that one hard 

 boiling will not always kill the germs. 



Cautions as to Drinking-water. If one uses tea and 

 coffee, it is safer to -content one's self with these, and not 

 drink much water till that which is safe, as from deep 

 wells, can be obtained. In hot weather, and especially 

 for those who are engaged in hard work, it has been 

 found that a little oatmeal stirred in the water is bene- 

 ficial. When overheated, avoid drinking much cold water. 

 Repeatedly 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 dur- 

 ing digestion and in other processes. We cannot live 

 without salt. Lime in the form of calcium phosphate and 

 calcium carbonate is essential, especially in the bones and 

 teeth. 



Necessity of a Mixed Diet. Our experience, together 

 with the results of experiments on animals, teaches that 

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

 stuffs 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 



