NITROGENOUS COMPOUNDS 59 



pyridine), C 6 H 7 N, lutidine, CyHgN, collidine, C 8 H n N, etc., are 

 derived from pyridine by substitution of H by CH 3 , C 2 H 5 , etc. 

 The quinoline bases also form a homologous series of the 

 general formula, C M H 2 ,,_nN. The lowest member of the 

 series bears the same relation to naphthalene as pyridine 

 bears to benzene. 



H H H H 



/ C \ / C \ / C \ / C \ 



HC C CH HC C CH 



I ! I I'll 



HC C CH HC C CH 



\ c / \C/ \ C / \N/ 



H H H 



(Naphthalene.) (Quinoline.) 



The other members of the series are derived from quino- 

 line, C 9 H 7 N, by substituting CH 3 and other alcohol radicles 

 for H. Lepidine, C 10 H 9 N, and cryptidine, C 1:L H 1:L N, are the 

 next two. 



Conine, C 8 H 17 N, a well-known volatile alkaloid obtained 

 from hemlock seeds, and nicotine, CioH^N^ which occurs in 

 the leaves and seeds of the tobacco plant, are both extremely 

 poisonous. 



Ptomaines. The ptomaines or toxines are another group 

 of amino bodies closely allied to the last. They are produced 

 by the decomposition of animal tissues by various putrefactive 

 organisms. They have been called the alkaloids of decay. 

 Bodies of this kind are practically innumerable, but the 

 following may be regarded as typical. 



Ethylene diamine, C 2 H 4 <^-^ 2 , is extremely poisonous. 



CH 2 .CH 2 .NH 2 



Tetramethylene diamine (putrescine), | , and 



CH 2 .CH 2 .NH 2 



CH NH 



pentamethylene diamine (cadaverine), ' 



are said to be non-poisonous. Neurine (ethyl-trimethyl- 



//~'TT \ 



ammonium hydroxide), x TJ 3 >NOH, which has been 



^ti 



