ANIMALS AND THEIR PRODUCTS. 113 



him warm and quiet, you might expect him to grow- 

 rapidly, because the 25 lbs. of hay would furnish food 

 for his lungs, and leave more than enough to supply 

 the natural waste of the body, and this surplus would 

 go to form new growth. If 3'ou were to give the same 

 feed to a similar ox, bu. were to work him 12 hours a 

 day, you could hardly expect him to grow much ; for, 

 being in such constant exercise, he would breathe a 

 great deal, and the food might no more than supply 

 fuel for his lungs, and leave enough to make up for 

 the natural waste of the body. Enough for this latter 

 purpose might not be left, and then he would fall away. 



201. If you were to give the same food to a third 

 ox similar to the other two, but were to turn him out 

 into a^bleak lot covered with snow, with no shelter 

 whatever, you might calculate for a certainty that he 

 would lose weight rapidly. The food, though enough 

 to make him grow, if he had been protected from the 

 cold, would not even supply fuel for his lungs; His 

 lungs would of course act powerfully. This is all that 

 would keep him from freezing. But it would require 

 a great deal of fuel to keep the fire burning within him. 

 The food would all be used up for this purpose ; afid 

 then drafts would be made upon the different parts 

 of his body. First the fat would go to the lungs, and 

 be breathed away in the forms of carbonic acid and 

 water. Then other parts, in proportion as they con- 

 tain carbon, would become fuel for the lungs, until 

 there would be little but skin and bones left. 



202. This would be an extreme case ; but something 



