FOODS AND DIETETICS. 77 



FOODS AND DIETETICS. 



During the functional activity of every organ and tissue of the body the 

 living material of which it is composed the protoplasm undergoes more or 

 less disintegration. Through a series of descending chemic stages it is 

 reduced to a number of simpler compound, which are of no further value to 

 the body, and which are in consequence eliminated by the various eliminat- 

 ing or excretory organs the lungs, kidneys, skin, liver. Among these com- 

 pounds the more important are carbon dioxide, urea, and uric acid. Many 

 other compounds, inorganic as well as organic, are also eliminated in 

 the water discharged from the body, in which they are held hi solution. 

 Coincident with this disintegration of the tissue there is an evolution or 

 disengagement of energy, particularly in the form of heat. 



In order that the tissues may regain their normal composition and thus be 

 enabled to continue in the performance of their functions, they must be sup- 

 plied with the same nutritive materials of which their protoplasm originally 

 consisted viz., water, inorganic salts, porteids, sugar, fat. These materials 

 are furnished by the blood during its passage through the capillary blood- 

 vessels. The blood is a reservoir of nutritive material in a condition to be 

 absorbed, organized, and transformed into new living tissue. 



Inasmuch as the loss of material from the body daily, which is very great, 

 is compensated for under other forms by the blood, it is evident that this 

 fluid would rapidly diminish in volume were it not restored by the intro- 

 duction of new and corresponding materials. As soon as the blood volume 

 falls to a certain point, the sensations of hunger and thirst arise, which 

 in a short time lead to the necessity of taking food. 



In addition to the direct appropriation of food by the tissues it is highly 

 provable that an indefinite amount undergoes oxidation and disintegration 

 without ever becoming an integral part of the tissues, and thus directly 

 contributes to the production of heat. 



Inanition or Starvation. If these nutritive principles be not supplied 

 in sufficient quantity, or if they are withheld entirely, a condition of physio- 

 logic decay is established, to which the term inanition or starvation is applied. 

 The phenomena which characterize this pathologic process are as follows 

 viz., hunger, intense thirst, gastric and intestinal uneasiness and pain, 

 muscle weakness and emaciation, a diminution in the quantity of carbon 

 dioxid exhaled, a lessening in the amount of urine and its constituents ex- 

 creted, a diminution in the volume of the blood, an exhalation of a fetid 

 odor from the body, vertigo, stupor, delirium, and at times convulsions, a 

 fall of bodily temperature, and, finally, death from exhaustion. 



