DIETETICAL PROPERTIES. 271 



is but natural therefore that there should be a craving 

 for warm food and drink, and as liquid food, partic- 

 ularly in a cold state, is deficient in heat-giving matter, 

 the use of cold liquids is more injurious than that of 

 cold solids. The temperature of the human body being 

 98, when food is taken into the stomach at a lower 

 temperature than that of the body, it obstructs the heat 

 from the stomach and surrounding tissues, so that when 

 the practice of taking cold food into the body becomes 

 habitual, depression occurs and the stomach is disordered. 

 The system must therefore make good the heat lost in 

 raising the temperature of the cold food hquid or soHd 

 or else suffer the consequences. 



The action of coffee as a diet is directed chiefly to the 

 nervous system, producing a warming cordial impression 

 on the stomach, which is quickly followed by a diffused 

 and agreeable nervous excitement which extends itself 

 to the cerebral function, giving rise to increased vigor of 

 the imagination and intellect, this too without any subse- 

 quent reaction or stupor such as are characteristic of liquor 

 and other narcotics. It contains essential principles of 

 nutrition far exceeding in importance its exhilarating 

 properties, and is one of the most valuable articles of food 

 for sustaining the system in certain protracted and wasting 

 diseases, and as compared even with the best soups, coffee 

 has a decided advantage and is to be preferred to them in 

 many cases. But to rightly understand its function as a food 

 it should be used chiefly as an accessary to food, as it aids 

 in the digestion and assimilation of the other foods 

 when it is properly prepared that is, by protracted 

 infusion as when boiled too long the caffeic acid or 

 tannin is extracted. The action of this acid in 

 combination with the milk and cream being to harden 

 the albumen into an indigestible compound, which has 



