168 VEGETABLE ALKALIES, &c. 



The effects of these substances are singularly varied ; 

 from the mildest form of the action of aloes, to the 

 most terrible poison, strychnia, we observe an endless 

 variety of different actions. 



With the exception of three, all these substances 

 produce diseased conditions in the healthy organism, 

 and are poisonous in certain doses. Most of them are, 

 chemically speaking, basic or alkaline. 



No remedy, devoid of nitrogen, possesses a poison- 

 ous action in a similar dose.* 



84. The medicinal or poisonous action of the nitro- 

 genized vegetable principles has a fixed relation to their 

 composition ; it cannot be supposed to be independent 

 of the nitrogen they contain, but is certainly not in di- 

 rect proportion to the quantity of nitrogen. 



Solanine (as), and picrotoxine (39), which contain 

 least nitrogen, are powerful poisons. Quinine (40) con- 

 tains more nitrogen than morphia (41). Caffeine (42), 

 and theobromine, the most highly nitrogenized of all 

 vegetable principles, are not poisonous. 



85. A nitrogenized body, which exerts, by means of 

 its elements, an influence on the formation or on the 

 quality of a secretion, must, in regard to its chemical 

 character, be capable of taking the same share as the 

 nitrogenized products of the animal body do in the for- 

 mation of the bile ; that is, it must play the same part 



* This consideration or comparative view has led lately to a more 

 accurate investigation of the composition of picrotoxine, the poison- 

 ous principle of cocculus indicus; and M. Francis has discovered the 

 existence of nitrogen in it, hitherto overlooked, and has also deter- 

 mined its amount. L. 



