VEGETABLE FOOD I2/ 



200. Tannin. Coffee and tea also contain some tan- 

 nin, which is a substance used in the manufacture of 

 leather. It puckers and contracts albumin with which 

 it comes in contact, and is liable to hinder digestion. 

 Much of the bad effect of strong tea is due to its tannin. 



201. Volatile oils. Both tea and coffee also contain a 

 considerable quantity of an oil, which gives the drinks their 

 peculiar odors and flavors, but which evaporates quickly. 

 It is mainly this oil which produces headache and sleep- 

 lessness and other troubles, when large quantities of tea or 

 coffee are taken. Yet both drinks agree with the stomach 

 better when the oil is retained in the drink. 



202. Preparation of tea and coffee. Both the caffeine and 

 the oil of tea and coffee are easily dissolved by, boiling water, but by 

 long boiling the volatile oil is driven off in the vapor, and a large 

 amount of tannin is extracted. Both these results are undesirable, and 

 can be avoided by pouring boiling water over the tea and coffee, a^id 

 then steeping it slowly for only a few minutes. 



Coffee will be digested more easily if the milk which is added is 

 boiled with the coffee. Better still would be to add no milk at all. 



203. Adulteration of tea and coffee. It is easy to add the 

 leaves of other plants to tea leaves. Green teas are often colored with 

 copper. 



Coffee is adulterated with all kinds of roasted roots. A root called 

 chicory is cultivated especially for this purpose. 



204. Cocoa. Cocoa contains a small quantity of a sub- 

 stance which stimulates like caffeine. It also contains a 

 considerable quantity of albumin and fat, both of which 

 will dissolve in water. Thus it is more of a food than tea 

 or coffee, and its use is less likely to cause indigestion. 

 Chocolate is a preparation of cocoa. 



205. Use of tea and coffee. Tea and coffee are not 

 necessities, and men would be just as healthy without 

 their use. They have a reputation of retarding waste 



