IN HYGIENIC PHYSIOLOGY. 175 



may do so, but one in ill health, or in a malarious district, 

 needs to be braced with food before taking any except very light 

 exercise. 



3. Why is warm food easier to digest than cold ? 



Heat favors the chemical change whereby the food is pre- 

 pared for assimilation. 



4. Why is salt beef less nutritious than fresh ? 



(See Physiology, p. 187, note.) 



The salts and juices of the meat are extracted by the brine, 



3. What should be the food of a man recovering from a 

 fever ? 



It should be that which is nutritious, easily digested, and 

 not over-stimulating. Beef-tea or essence * is generally com- 

 mended. As soon as the patient will bear it, beefsteak, tender, 

 broiled, and not overdone, is most beneficial. 



0. Is a cup of black coffee a healthful close to a hearty 

 dinner ? 



The tannic acid contained in tea and coffee is neutralized 

 by the milk generally used with these beverages. In cafe noir, 

 black or clear coffee, the tannic acid acts unfavorably on the 

 mucous membrane lining the stomach. Besides, the coffee, like 

 a dessert, is superfluous, the appetite being already satisfied. 

 It therefore tends, both actively and negatively, to delay the 

 digestion of the meal. The glass of wine sometimes taken to 

 aid digestion merely deadens the sensibility of the stomach, so 

 that the food is hurried, half-digested, out into the intestines, f 



* Dr. Martindale gives the following recipe for making this essence : 

 Cat a quantity of lean beef into small pieces, put it into a strong bottle, 

 without water, cork it loosely, so that the steam can escape, and immerse 

 tho bottle to its neck in a vessel of cold water. Place on the fire, and boil 

 for two hours ; then pour off the essence. 



t Mix some bread and meat with gastric juice ; place them in a vial, 

 and keep that vial in a sand-bath at the slow heat of 98 degrees, occasion- 

 ally shaking briskly the contents, to imitate the motion of the stomach ; 

 you will find, after six or eight hours, the whole contents blended into one 



