OF AGRICULTURE. 167 



Apart from the relations between the organic parts 

 of plants, and those of animals ; there exists an 

 important relation between their ashes or their 

 mineral parts ; and food, in order to supply the 

 demands of animal life, must contain the mineral 

 matter required for the purposes of life. 



Take bones, for instance : If phosphate of lime is 

 not always supplied, in sufficient quantities, in the 

 food, animals are prevented from forming healthy 

 bones. This is particularly noticed in the teeth. 

 When food is deficient in the phosphate of lime, W T C 

 see poor teeth as the result. 



Some eminent physicians have supposed that one 

 of the causes of consumption, is the deficiency of 

 phosphate of lime in food. The first class of vegeta- 

 ble constituents (starch, sugar, gum, etc),, performs 

 an important office in the animal economy,, aside from 

 their use in making fat. They constitute the fuel, 

 which supplies the animal's fire, and gives him heat, 

 The lungs are the delicate stoves, which supply the 

 whole body with heat. 



Let us explain this matter more fully. If wood, 

 starch, gum, or sugar, be burned in a stove, they 

 produce heat. These substances consist of carbon r 

 hydrogen, and oxygen, and when they are destroyed 

 in any way (provided they are exposed to the air), 

 the hydrogen and oxygen unite and form water, and 

 the carbon unites with the oxygen of the air, and 

 forms carbonic acid. This process is always accom- 

 panied by the production of heat, and the intensity of 

 this heat depends on the time occupied in its production. 



In the lungs and blood vessels of animals, the same 

 law holds true. The blood contains carbonaceous 



