lilUAL OF CATTLE-EEEDIN&. 



mTEODUCTION. 



The two objects of agriculture are the production of 

 plants and of animals. 



We must seek for the laws governing the former in the 

 cliernistry and physics of the air, the soil, and manures, 

 and in the phenomena of vegetable growth ; while a scien- 

 tific study of the latter involves a consideration of the laws 

 of animal nutrition and growth, and of the ohamistry of 

 plants, so far as they are used as food. 



All forms of life with which we are acquainted, vegeta- 

 ble as well as animal, manifest themselves through the 

 breaking up of more complex into simpler compounds, 

 accompanied by a liberation of energy. 



The broad distinction between vegetable and animal life 

 is, that plants are able to appropriate the force which ex- 

 ists in the sun's rays and use it to build up these complex 

 compounds out of very simple, so-called inorganie mate- 

 rials, while animals lack this power^ and are obliged to 

 avail themselves of the compounds already formed by 

 plants. 



In the economy of nature, the office of the plant is to 

 store up energy from the sun's rays in certain complex 

 compounds, setting free oxygen in the process ; while the 



