232 AGRICULTURAL CHEMISTRY 



plant bodies, but not found in any appreciable amount in 

 food plants. They are basic in character and unite with 

 acids to form salts, just as ammonia unites with acids 

 to form salts. Quinin, for example, in an alkaloid, and 

 with sulfuric acid yields quinin sulfate. Animal alka- 

 loids are sometimes called ptomaines and leucomaines. 

 The vegetable alkaloids are generally named from the 

 species of plant or source from which they are obtained , 

 as Peruvian bark alkaloids, lupine alkaloids, and opium 

 alkaloids. 



321. Plant Alkaloids. No alkaloids are found in 

 cereals or ordinary food plants, though at one time it 

 was supposed that oats contained such a stimulating 

 body to which the name avenin was given; later investi- 

 gations have shown that there is no avenin or alkaloidal 

 body in oats. The alkaloids chemically are closely 

 related to the amines, and are produced by the action of 

 amido compounds upon other bodies. They are also 

 produced by the action of fungus bodies, as eargotin, the 

 alkaloid from eargot or grain smut. While found most 

 abundantly in the leaves and seeds, they are found in all 

 parts of plants. Some are cultivated for these bodies 

 which possess medicinal properties. Many poisonous 

 weeds contain alkaloids as the water hemlock and 

 monk's hood. Large numbers of alkaloids are known, 

 and since they possess medicinal rather than food value, 

 they are of more importance to the medical and pharma- 

 ceutical than to the agricultural student. A few of the 

 more common alkaloids and their sources are : 



Piperine, from seeds of black pepper. 



