Proceedings of the A. A. A. S. 515 



the French chemist, "Wurtz, produced the first chemical 

 derivatives of ammonia by substitution. The names of 

 " methylamine" and " ethylamine" then given by our own 

 Dr. Sterry Hunt, are the names that remain. A. W. Hof- 

 mann, who still directs the Berlin laboratory, when in 

 England in 1850, devised means of introducing groups of 

 one or two, or all three atoms of hydrogen, held by the one 

 atom of nitrogen in ammonia. This reaction of Hofmann 

 is of constant and still increasing usefulness, both in re- 

 search and manufacture. Simply as derivatives of ammonia, 

 however, the structure of vegetable alkaloids has not been 

 revealed. 



(2) Nitrogenous bases represented by aniline. These 

 artificial alkaloids, extensively produced as color-stuffs from 

 coal-tar materials, are of the so-called "aromatic" constitu- 

 tion, first brought to light by Kekule in 1865 The vege- 

 table alkaloids, when broken up, yield "aromatic" products, 

 but they have not been found actually to possess the 

 " aromatic structure" in any form of it known earlier 

 than 18^0. 



• (3) The pyridine type in the vegetable alkaloids. The 

 constitution of the pyridine and quinoline series was ascer- 

 tained by Koerner and by Baeyer in 1870. These bodies 

 can be obtained from bone-oil and from coal-tar. They are 

 of a remarkable ehemical structure. Like aniline, they 

 have the closed chain of six positions, but, unlike aniline, 

 they have one of these positions held by nitrogen. The in- 

 troduction of the atom of nitrogen into the closed ring so 

 affects the qualities of the molecule that stable addition 

 products are formed. About 1879 it began to appear that 

 the vegetable alkaloids in general are of the pyridine type, 

 of "aromatic" composition. 



In this type the structure of ammonia is not violated ; 

 and the theories of Liebeg, Wurtz and Hofmann, are not 

 superseded. Within the last three or four years, the veil 

 has been da-awn from the structure of the chief alkaloids of 

 plants. Even before that, the alkaloids of black pepper, 

 tobacco and hemlock, of very simple composition, were 

 studied with success. The alkaloids of the belladonna 



