400 LOBELIACEiE. 



trimmed. The cakes arrive wrapped in paper, sealed up and bearing 

 the label of some American druggist or herb-grower, 



•Lobelia has a herby smell and, after being chewed, a burning acrid 

 taste resembling that of tobacco. 



Chemical Composition — Lobelia has been examined by Procter, 

 Pereira (1842), Reinsch^ (1843), Bastick (1851), also by F. F. Mayer.^ 

 The first-named chemist^ traced the activity of the plant to an alkaloid 

 which he termed Lohelina, and his observations were confirmed by the 

 independent experiments of Bastick.^ Lewis (1878) obtained it by 

 mixing the drug with charcoal and exhausting the powder with water 

 containing a little acetic acid. The liquid is cautiously evaporated to 

 the consistency of an extract and triturated with magnesia, from the 

 excess of which the aqueous solution of lobeline is separated by filtra- 

 tion. It is agitated with amylic alcohol (or ether), which by spontane- 

 ous evaporation afibrds the alkaloid. The latter is again dissolved in 

 water and filtered through animal charcoal; from the dried powder 

 lobeline is to be removed by ether. 



Lobeline is an oily, yellowish fluid with a strong alkaline reaction, 

 especially when in solution. In the pure state it smells slightly of the 

 plant, but more strongly when mixed with ammonia. Its taste is 

 pungent and tobacco-like, and when taken in minute doses, it exercises 

 in a potent manner the poisonous action of the drug. Lobeline is to 

 some extent volatile, but its decomposition begins when it is heated to 

 100° C. either pure or in presence of dilute acids or caustic alkalis. 

 Lobeline dissolves in water, but more readily in alcohol or ether, the 

 latter of which is capable of removing it from its aqueous solution. It 

 neutralizes acids, forming with some of them crystallizable salts, soluble 

 in water or alcohol. 



The herb likewise contains traces of essential oil (the Lobelianin of 

 Pereira ?), resin and gum. The seeds afibrded Procter about 30 per 

 cent, of fixed oil, sp. gr. 0'940, which was found to dry very rapidly. The 

 Loheliin of Reinsch appears to be an indefinite compound. 



In 1871 Enders at our request performed some researches on Lobelia 

 in order to isolate the acrid substance to which the herb owes its taste. 

 He exhausted the drug with spirit of wine and distilled the liquid in 

 presence of charcoal, which then retained the acrid principle. The char- 

 coal was washed with water, and then treated with boiling alcohol. 

 This on evaporation yielded a green extract, which was further purified 

 by means of chloroform. Warty tufts were thus finally obtained, yet 

 always of a brownish colour. The tufts are readily soluble in ether and 

 chloroform, but only slightly in water ; they possess the acrid taste of 

 lobelia. This substance, which we may term Lobelacrin, is decomposed 

 if merely boiled with water ; by the influence of alkalis or acids it is 

 resolved into sugar and Lobelic Acid. The latter is soluble in ether, 

 water, and alcohol, and is non- volatile ; it yields a soluble salt with 

 baryum oxide, whereas its plumbic salt is insoluble in water. 



Lewis suggests that lobelacrin is nothing else than lobeliate of 

 lobeline, which he believes to exist ready formed in the plant. From a 



^American Jonrn. of Pharm. xxx%ni. ^ Am. Joum. of Pharm, iii. (1838) 98; 



(1866) 209; also Jahresberkht of Wiggers vii. (1841) 1 ; Pharm. Joum. x.(1851)456. 

 and Husemanu, 1866. 252. '^ Pharm. Joum. x. (1851) 270. 



