FKKDTNd STOCK. 43 



world is composed of carbon. It appears to be very 

 plentiful, but of our atmosphere it composes only about 

 Ibur-ten-thonsandth.s, while oxygen, with which it unites 

 to form carbonic acid gas for vegetation to feed on, .com- 

 poses one-fifth and nitrogen four-fifths. Really, we have 

 link- trouble in securing carbonaceous foods. The only 

 difficulty is to get them in a digestible form. Only what 

 is soluble can be digested and assimilated by the animal 

 organism. Hence, great care must be taken to get food 

 in a proper condition for animal nutrition. 



WHAT IS NITROGEN? 



It is almost pure in the albumens, both vegetable and 

 animal. It is nearly pure in the white of egg. Hence, 

 nitrogenous foods are quite commonly called albumin- 

 oids. It exists abundantly in all the proteins as cheese 

 or caseine, fibrin or lean meat, albumen, etc. Nitrogen, 

 in its free state, appears to be an innocuous gas, diluting 

 the oxygen and preventing it from rapidly oxydizing or 

 burning up everything. As before said, it constitutes 

 four-fifths of our atmosphere, but does not appear to be 

 directly appropriated by either vegetables or nnimals. 

 As food for either, it must be in combination with other 

 elements especially carbon and yet it is very difficult 

 to make it unite with other elements, and hard to main- 

 tain the union when it is once formed. Its disposition is 

 to break these unions and seek an idle state of freedom. 

 Hence it is that, when held in durance, its constant ten- 

 dency to free itself makes it the motor force in all animal 

 organisms, and the terrible energy in all explosives. It 



