CATTLE FEEDING. 



129 



The Plant. 



By a rapid siirvej' of the proximate composition of most of the 

 products of the vegetable kingdom, we can easil}' convince ourselves 

 of the great fitness of phmts as tlie food o& animals. 



Albuminoids. By expressing the juice from the potato, for 

 example, and heating it, we coagulate a sul)stance called vegetable 

 albumin, which has properties very closely resembling those of the 

 albumin of the egg. 



By taking the flour of some cereal, especially wheat, and knead- 

 ing the dough obtained from it under running water, we will obtain 

 after sometime, a yellowish, tough mass, called gluten or vegetable 

 fibrin, and which closely I'esembles, both in properties and composi- 

 tion, animal fibrin. The meal of leguminous plants, such as peas 

 and beans, when treated with cold water gives a solution which is 

 coagulated by the addition of an acid. This coagulum is called 

 vegetable casein or legumin, and compares closely with the casein of 

 milk. All these varieties of vegetable albuminoids bear a strong 

 resemblance to one another ; their chemical composition is nearly 

 the same as shown b}"^ the following table : 



Vegetable Albumin. Veg. Fibrin. Veg. Casein. Average. 



Carbon 53.7 per ct. 53.2 per ct. 53.5 per ct. 53.5 per ct. 



Hydrogen... 7.1 " 7.0 '' 7.1 " 7.1 " 



Oxygen 23.5* " 23.3 " 23.4 " 23.4 " 



Nitrogen 15.7 " 1G.5 " 16.0 " 16.0 " 



By comparing this table with that giving the composition of the 

 animal albuminoids, one is immediately struck by their great simi- 

 larity. From this it would seem probable that the vegetable 

 albuminoids need not be greatl}' changed by the animal organism in 

 order to be fit for its use. All these bodies are very important, as 

 the}' are necessary for nearly every animal production which is of 

 value, and it is onlj^ to be regretted that they generally exist in 

 such small quantities in plants ; as the vegetable kingdom is the great 

 source of albuminous food for most of our domestic animals. 



Carbohydrates. Substances containing carbon, hydrogen, and 

 oxj'gen, the two last in the same ratio as they exist in water, that is 

 twice as manj- hydrogen atoms as there are oxygen atoms. 



These ma}- be divided into two classes. The first containing 

 woody fibre or ligniu or cellulose, in a more or less incrusted condi- 

 9 



