22 ALIMENTATION. 



with dry food, but deprived of water, will not survive beyond 

 a few days. Water is necessary to the function of nutrition, 

 and acts, moreover, as a solvent in removing from the system 

 the products of destructive assimilation. 



After deprivation of water for a considerable time, the 

 intense thirst becomes most agonizing. The dryness and 

 heat of the throat and fauces are increased, and accompanied 

 by a distressing sense of constriction. A general febrile 

 condition supervenes, the blood is diminished in quantity 

 and becomes thickened, the urine is scanty and scalding, and 

 there seems to be a condition of the principal viscera ap- 

 proaching inflammation. Death takes place in a few days, 

 generally preceded by delirium. 



The sensation of thirst is instinctively referred to the 

 mouth, throat, and fauces ; but it is not necessarily appeased 

 by the passage of water over these parts, and it may be 

 effectually relieved by the introduction of water into the 

 system by other channels, as by injecting it into the veins. 

 Bernard has demonstrated by the following experiment that 

 water must be absorbed before the demands of the system 

 can be satisfied: He made an opening into the oesopha- 

 gus of a horse, tied the lower portion, and allowed the 

 animal to drink, after he had been deprived of water for a 

 number of hours. The animal drank an immense quantity, 

 but the water did not pass into the stomach, and the thirst 

 was not relieved. He modified this experiment by causing 

 dogs to drink with a fistulous opening into the stomach by 

 which the water was immediately discharged. They contin- 

 ued to drink without being satisfied, until the fistula was 

 closed and the water could be absorbed. 1 We have often 

 repeated the latter experiment in public demonstrations. In 



this does not take place in birds, in which starvation seems to take away the 

 desire for drink (CnossAT, Recherches Experimentales sur I* Inanition, Paris, 1843, 

 p. 59). 



1 BERNARD, Legons de Physiologic Experimentale, cours de semestre cTete } Paris, 

 1856, p. 61. 



