ALKALOIDS. 319 



Formation of amines and amides. Amines and amides may be 

 formed by the action of ammonia upon the chloride or iodide 

 of an alcohol or acid radical : 



C 2 H 5 .I + NH 3 = HI + NII 2 .C 2 H 5 . 



Ethyl iodide. Ammonia. Hydriodic Ethylamine. 



acid. 



C 2 H 3 O.C1 + 2NH 3 = NH 4 C1 + NH 2 .C 2 H 3 O. 



Acetyl Ammonia. Ammonium Acetamide. 



chloride. chloride. 



Amines may also be formed by the action of nascent hydrogen 

 upon the cyanides of the alcoholic radicals : 



CH 3 CN + 4H = NH 2 .C 2 H 5 . 



Methyl cyanide. Ethylamine. 



Aniline, Phenylamine, NH 2 .C 6 H 5 . Amines may in some cases 

 be formed by the action of nascent hydrogen upon nitro-com- 

 pounds ; the manufacture of aniline depends on this decom- 

 position : 



C 6 H 6 NO 2 + 6H = 2H 2 O + NH 2 .C 6 H 5 . 



Nitro-benzene. Hydrogen. Water. Phenylamine. 



Pure aniline is a colorless, neutral liquid, having a peculiar, 

 aromatic odor. Oxidizing agents, such as arsenious and arsenic 

 oxide, chromic oxide, chlorides, nitrates, etc., convert it into 

 blue, red, violet, green, or black derivatives; the substances 

 thus formed are the various aniline colors, which are now manu- 

 factured on a large scale. 



Occurrence of organic bases in nature. (Alkaloids.) The various 

 organic basic substances found in nature are either amines 

 (compounds containing carbon, hydrogen, and nitrogen only), 

 or amides (compounds containing, besides the three elements 

 named, also oxygen). But a small number of organic bases is 

 found in the animal system, urea being the most important one. 

 In plants organic bases are more frequently met with, and are 

 grouped together under the name of alkaloids, this term signify- 

 ing alkali-like in allusion to the alkaline or basic properties of 

 these substances. 



Alkaloids are found in the leaves, stems, roots, barks, and 

 .seeds of various plants ; it often happens that a certain alkaloid 



