FOODS AND DIETETICS. 91 



The accessory foods, coffee and tea, when taken in moderation, 

 overcome the sense of fatigue and mental unrest consequent on exces- 

 sive physical and mental exertion. Coffee increases the action of the 

 intestinal glands and acts as a laxative. After absorption, its active 

 principle, caffein, stimulates the action of the heart, raises the 

 arterial pressure, and excites the action of the brain. Tea acts as 

 an astringent, owing to the tannic acid it contains. One effect of 

 the tannic acid is to coagulate the digestive ferments and to interfere 

 with the activity of the digestive process. 



Alcohol, when introduced into the system in small quantities, under- 

 goes oxidation and contributes to the production of force, and is 

 thus far a food. It excites the gastric glands to increased secretion, 

 improves the digestion, accelerates the action of the heart, and stimu- 

 lates the activities of the nerve centers. In zymotic diseases, and in 

 all cases of depression of the vital powers, it is most useful as a 

 restorative agent. When taken in excessive quantities, it is elimi- 

 nated by the lungs and kidneys. The metamorphosis of the tissue is 

 retarded, the elimination of urea and carbonic acid is lessened, the 

 temperature is lowered, the muscular powers are impaired, and the 

 resistance to depressing external influences is diminished. When 

 taken throughout a long period of time, alcohol impairs digestion, 

 produces gastric catarrh, and disorders the secreting power of the 

 hepatic cells. It also diminishes the muscular power and destroys 

 the structure and composition of the cells of the brain and spinal 

 cord. The connective tissue of the body increases in amount, and, 

 subsequently contracting, gives rise to sclerosis. 



A proper combination of various alimentary principles is essential 

 for healthy nutrition, no one class being capable of maintaining life 

 for any definite length of time. 



The albuminous food in excess promotes the arthritic diathesis, 

 manifesting itself as gout, gravel, etc. 



The oleaginous food in excess gives rise to the bilious diathesis, 

 while a deficiency of it promotes the scrofulous. 



The farinaceous food when long continued in excess, favors the 

 rheumatic diathesis by the development of lactic acid. 



The quantities of the different nutritive materials which are 

 required daily for the growth and repair of the tissues and for the 

 evolution of heat have been variously estimated by different ob- 

 servers. The following table shows the average diet scale of Vierbrdt, 

 and the amount of waste products to which it would give rise : 



