FOODS AND DIETARIES 289 



So if a person reads the label he can determine exactly what he 

 is getting for his money. 



Impure Water. Great danger comes from drinking impure 

 water. This subject has already been discussed under Bacteria, 

 where it was seen that the spread of typhoid fever in particular is 

 due to a contaminated water supply. As citizens, we must aid all 

 legislation that will safeguard the water used by our towns and 

 cities. Boiling water for ten minutes or longer will render it 

 safe from all organic impurities. 



Stimulants. We have learned that food is anything that 

 supplies building material or releases energy in the body ; but 

 some materials used by man, presumably as food, do not come 

 under this head. Such are tea and coffee. When taken in 

 moderate quantities, they produce a temporary increase in the 

 vital activities of the person taking them. This is said to be a 

 stimulation ; and material taken into the digestive tract, produc- 

 ing this, is called a stimulant. In moderation, tea and coffee 

 appear to be harmless. Some people, however, cannot use either 

 without ill effects, even in small quantity. It is the habit formed 

 of relying upon the stimulus given by tea or coffee that makes 

 them a dangor to man. Cocoa and chocolate, -although both 

 contain a stimulant, are in addition good foods, having from 12 

 per cent to 21 per cent of protein, from 29 per cent to 48 per cent 

 fat, and over 30 per cent carbohydrate in their composition. 



Is Alcohol a Food ? The question of the use of alcohol has 

 been of late years a matter of absorbing interest and importance 

 among physiologists. A few years ago Dr. Atwater performed a 

 series of very careful experiments by means of the respiration 

 calorimeter, to ascertain whether alcohol is of use to the body as 

 food. 1 In these experiments the subjects were given, instead of 

 their daily allotment of carbohydrates and fats, enough alcohol 

 to supply the same amount of energy that these foods would 

 have given. The amount was calculated to be about two and 

 one half ounces per day, about as much as would be contained in 



1 Alcohol is made up of carbon, oxygen, and hydrogen. It is very easily oxidized, 

 but it cannot, as is shown by the chemical formula, be of use to the body in tissue 

 building, because of its lack of nitrogen. 

 HUNTER, CIV. BI. 19 



