166 THE CHEMISTRY OP THE FABM 



A warm atmosphere, and exercise, will greatly increase 

 the amount of perspiration, and consequently the 

 amount of water consumed (p. 185). 



With sheep the normal proportion of water to dry 

 food is about 2:1; with horses 2 — 3 : 1 ; with cattle 

 3 — 4 : 1. Sheep recently shorn require less water than 

 sheep with a heavy fleece. 



Roots contain an excessive amount of water. A. 

 sheep feeding on turnips in winter in the open field, 

 consuming, say, 20 lbs. of roots per day, will receive in 

 its food about 18'4 lbs. of water, of which 15*2 lbs. is 

 beyond that necessary for nutrition. This 15*2 lbs. of 

 water has to be raised from near the freezing point ta 

 the temperature of the sheep's body, a rise of 70° Fahr. 

 To warm the water to this extent will require the com- 

 bustion of about 73 grams of dextrose (the sugar in 

 turnips), equal to nearly 11 per cent, of the total food 

 consumed. The actual waste of food will, however, 

 greatly exceed this, as a part of the extra water will be 

 exhaled as vapour in the breath and perspiration, and 

 to vaporise 1 lb. of water at the temperature of the 

 animal body requires the combustion of 66 grams of 

 dextrose. The consumption of an excess of water will 

 also somewhat increase the amount of albuminoids 

 oxidised in the animal body, and thus occasion a waste 

 of the nitrogenous part of the food. 



The economy of supplying sheep on roots or green 

 fodder with dry food in addition is obvious from the 

 facts just stated. By so doing, the quantity of water 

 consumed by the animal is diminished, and its pro- 

 portion in the diet brought more nearly to a normal 

 ratio. 



(5) General Conclusions. — Attempts have often been 



