168 ALIMENTATION. 



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 oesophagus 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 ani- 

 mal 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 continued to drink without being satis- 

 fied, until the fistula was closed and the water could be absorbed. 



In a case reported by Gairdner (1820), in the human subject, all the 

 liquids swallowed passed out at a wound in the neck, by which the oesophagus 

 had been cut across. The thirst in this case was insatiable, although 

 buckets of water were taken in the day ; but on injecting water, mixed with 

 a little spirit, into the stomach, the sensation was soon relieved. 



Although the sensation of thirst is referred to special parts, it is an ex- 

 pression of the want of liquids in the system and is to be effectually relieved 

 only by their absorption by the blood. There are no nerves belonging to the 

 cerebro-spinal system which have the office of conveying this sensation to the 

 brain, division of which will abolish the desire for liquids. Experiments 

 show that no effectual relief of the sensation is afforded by simply moistening 

 the parts to which the heat and dryness are referred. As a demand on the 

 part of the system, it is entirely analogous to the sense of want of air and of 

 hunger, differing only in the way in which it is manifested. 



The length of time that life continues after complete deprivation of food 

 and drink is very variable. The influences of age and obesity have already 

 been referred to. Without citing the individual instances of starvation in 

 the human subject which have been reported, it may be stated, in general 

 terms, that death occurs within five to eight days after total deprivation 

 of food. In the instance of the one hundred and fifty persons, wrecked on 

 the frigate Medusa, in 1816, who were exposed cm a raft in the open sea for 

 thirteen days, only fifteen were found alive. Savigny, one of the survivors, 

 gave, in an inaugural thesis, a very instructive and accurate account of this 

 occurrence, which has been very generally quoted in works of physiology. 

 Authentic instances are on record in which life has been prolonged much 

 beyond the period above mentioned ; but they generally occurred in persons 

 who were so situated as not to suffer from cold, which the system, under this 

 condition, has very little power to resist. In these cases, also, there was no 

 muscular exertion, and water was generally taken in abundance. 



Berard quoted the example of a convict who died of starvation after sixty- 

 three days, but in this case water was taken. An instance of eight miners 

 who survived after five days and sixteen hours of almost complete deprivation 

 of food is referred to in works upon physiology. Berard has also quoted, from 

 various authors, instances of deprivation of food for periods varying between 

 four months and sixteen years ; but these accounts are not properly authen- 

 ticated and are discredited by physiologists. They generally occurred in 

 hysterical females, and their consideration belongs to psychology rather than 



