164 ALIMENTATION. 



of the eight hours. Many of those who immediately survived died afterward 

 of putrid fever ("Annual Eegister," 1758). The incident of the "Black 

 Hole of Calcutta " has frequently been repeated on emigrant and slave ships, 

 by confining great numbers in the hold of the vessel, where they were 

 entirely shut out from the fresh air. 



The condition of the system has a marked and important influence on 

 the rapidity with which the effects of vitiated atmosphere are manifested. 

 As a rule, the immediate effects of confined air are not developed so soon in 

 weak and debilitated persons as in those who are active and powerful. It 

 has sometimes been observed, in cases where a male and female have attempted 

 suicide together by the fumes of charcoal, that the female has been restored 

 some time after life had become extinct in the male. This is probably owing 

 to the greater demand for oxygen on the part of the male. 



When poisoning by confined air is gradual, the system becomes accus- 

 tomed to the toxic influence, the temperature of the body is lowered, and an 

 animal will live in an atmosphere which will produce instantaneous death in 

 one that is fresh and vigorous. Bernard has made a number of experiments 

 on this point. In one of them, a sparrow was confined under a bell-glass for 

 an hour and a half, at the end of which time another was introduced, the 

 first being still quite vigorous. The second became instantly much distressed 

 and died in five minutes; but ten minutes after, the sparrow which had 

 been confined for more than an hour and a half was released and flew away. 



CHAPTER VI. 



ALIMENT A TION. 



General considerations Hunger Seat of the sense of hunger Thirst Seat of the sense of thirst Dura- 

 tion of life in inanition Classification of alimentary substances Nitrogenized alimentary substances 

 Non-nitrogenized alimentary substances Inorganic alimentary substances Alcohol Coffee Tea 

 Chocolate Condiments and flavoring articles Quantity and variety of food necessary to nutrition 

 Necessity of a varied diet. 



IN the organism of animals, every part is continually undergoing what 

 may be called physiological wear ; the nitrogenized constituents of the body 

 are being constantly transformed into effete matter ; and as these constitu- 

 ents never exist without inorganic matters, with which they are closely and 

 inseparably united, it is found that the products of their disassimilation 

 are always discharged from the body in combination with inorganic sub- 

 stances. This process of molecular change is a necessary condition of life. 

 Its activity may be increased or retarded by various means, but it can not be 

 arrested. The excrementitious matters which are thus formed are produced 

 constantly by the tissues and must be continually removed from the or- 

 ganism. 



