2 ELEMENTARY TREATISE ON STOCK FEEDS AND FEEDING 



Action of the Plant on the Animal. The plant is the animals' 

 food. The plant builds them up, it keeps them warm and it 

 furnishes substances which are changed into energy and motive 

 power. No matter how cold it may be, we find that the plant 

 enables the animal to maintain a constant body temperature. 

 This temperature, in cold weather, is much warmer than the 

 surrounding air, and in hot weather, it is cooler than the out- 

 side air. Take any young animal and feed it plant substances, 

 such as grain and hay, and it continues to take on bone and 

 flesh until it becomes large and heavy. As the animal re- 

 quires for its existence, those substances which the plant stores 

 up, we may properly call plant substances animals' food or feed 

 stuffs. 



Chemical Elements Needed by Plants. All forms of matter 

 in this world are made up of chemical elements in various com- 

 binations. There are about 81 chemical elements known to us, 

 but. only 15 of these are required for plant life so far as we 

 know. In order to thoroughly understand this subject of feeds 

 and feeding let us become acquainted with these fifteen elements. 



The Fifteen Elements. Hydrogen, oxygen, nitrogen, carbon, 

 potassium, phosphorus, calcium, sulphur, silicon, iron, chlorine, 

 magnesium, sodium, 'fluorine, and manganese are the elements 

 used by plants. Some of these elements are used in much larger 

 amounts than others. Hydrogen, oxygen, nitrogen and chlorine, 

 in the pure state, generally occur as gases, while the other 

 elements are solids. 



Small amounts of oxygen are sometimes used by plants in the 

 elementary state. Certain plants also use nitrogen in the free 

 state. All the other elements, and generally oxygen and nitrogen, 

 must be combined with other of these elements to be favorable 

 for the support of plant life. 



Hydrogen. This element is generally found in combination 

 with other elements. In the free state it occurs only in small 1 

 quantities upon the earth. It is present in the gases of petroleum 

 wells, around volcanic eruptions, and it is evolved by the fer- 

 mentation and decomposition of some organic substances. It 

 is abundantly found in combination with other elements. Water, 



