ON WATERING HORSES yt 



The office of the sensation of thirst is to cause the 

 animal to desire to drink water, when there is a deficiency 

 of that fluid in his blood. 



The stomach is furnished with a vast number of blood- 

 vessels, the office of which is to absorb water for the 

 supply of the glands that secrete the gastric juice. As 

 the amount of the secretion, necessary for digestion, varies 

 from 10 to 20 gallons daily {Brinton), and as about 99 per 

 cent, of it is composed of water, we find that the process 

 of digestion, during the day, demands the outpouring, for 

 the formation of gastric juice, of double or treble as much 

 water, as there is blood in the whole body. Now, as this 

 water is derived directly from the blood, its adequate 

 supply can only be obtained by the constant reabsorption, 

 in the stomach, of the watery portion of the effete gastric 

 juice, as well as of that of other fluids which may be 

 present. Considering the enormous quantity of water 

 required for the secretion of the gastric juice, we may 

 accept the fact that drinking a small quantity of water 

 with the food is not alone free from objection, but may be 

 actually beneficial. On this point we may safely trust 

 to the instinct of the animal, and may consequently leave 

 a supply of water before him while he is eating ; provided 

 always that he has had a full opportunity of drinkinc? 

 shortly before being fed. 



If (as we have seen in the preceding chapter), while 

 digestion be going on, a large amount of water be taken 

 into the stomach, it will dilute the gastric juice to an 

 extent that will probably arrest its action, until the excess 

 of water becomes absorbed. During this interval, de- 

 composition of the food, with consequent derangement of 



