528  LEGUMINOS£. 
cuneate, compressed; cotyledons plain, extending thelarge 
diameter of the seed in transverse section. (Oliver.) 
Chemical composition.—According to the researches 
Lassaigne and Feneulle (1821), Bucheim and Lundermann (185 
and Kubly (1865), the active principle of senna leaves 
cathartin, a combination of cathartic acid with one or more 
earthy bases. Cathartic acid has been shown to be formed 0} 
carbon, hydrogen, oxygen, nitrogen and sulphar; it is quite 
soluble in alcohol, but the salts are insoluble, hence the cath 
treating Senna leaves with alcohol acidulated with weak 
sulphuric acid, afterwards with hot alcohol; the result of this. 
process was precipitated by hydrate of wey te In the precipita 
and in the filtered liquid cathartic acid is found, which i8 
dissolved and shaken with ether, and the acid is then combined og 
with baryta or lead. The liquid which contains the active 
principle is evaporated after being treated with sulphuretted 
hydrogen, and the resulting product dried over sulphuric acid. — 
A solution of this substance neutralised by carbonate of soda 
and administered to rabbits produced a violent diarrhoea, in 
large doses it is poisonous ; injected hypodermically or into the 
_ veins it produces no effect. (Archiv. der. Phar., Journ de Phar. é 
de Chim., 1886. 
The sugar of Senna leaves was isolated by Kubly i in 1865, 
and named Catharto-mannit. A, Seidel, 1885, has further exa- 
mined this substance, for which he proposes the name “‘ Sennit = 
‘The most satisfactory process for preparing this sugar was by 
‘concentrating in vacuo the aqueous infusion of the leaves» 
recipitating mucilage and salts from the syrupy 1 liquid by ty ; 
rolumes of — alcohol, filtering, distilling off the ¥ 
