29 POLYGALA SENEGA 



disagreeable, and rancid; and its taste at first sweetish, but 

 ultimately very acrid and sourish, and when chewed exciting cough 

 and salivation. The odour and taste reside entirely in the bark 

 or cortical portion, the meditullium being quite inert. 



Senega root owes its properties essentially to the presence of a 

 peculiar principle which has been termed senegin or polygalic acid, 

 which is said to be closely allied to saponin. Senega root also 

 contains a little volatile oil, resin, sugar, and other unimportant 

 constituents. Senegin is a white amorphous powder, insoluble in 

 cold water and ether, but soluble in alcohol and boiling water, 

 with which latter it forms a feebly acid frothy solution. Accord- 

 ing to Procter, the root yields about 5J per cent, of senegin, which 

 is present in the bark only. Senegin is a poisonous substance, 

 with a very acrid taste, and excites violent sneezing. Quevenne 

 regards it as a glucoside, as it is resolvable by the dilute mineral 

 acids and alkalies into a jelly-like substance called sapogenin, and 

 sugar, which remains in solution. 



Adulterations. Senega root does not appear to be intention- 

 ally adulterated, but from carelessness in collection some other 

 roots or rhizomes in small proportion may be frequently found 

 mixed with it. American Ginseng root, from Panax quinquefolium, 

 is that most commonly found, and is readily distinguished by its 

 greater size, more or less fusiform shape, and by the absence 

 of any projecting line. The roots of Gillenia trifoliata and other 

 species of Gillenia ; and the rhizome of Cypripedium pubescens 

 have also been noticed in parcels of senega root. They are 

 readily distinguished by the absence of any projecting line, and 

 by their different taste and odour. 



Medical Properties and Uses. Senega root was introduced into 

 practice as a remedy for the bite of the rattlesnake, but it is now 

 known to be useless in such a case, and also in the bites of other 

 venomous reptiles. Senega root appears to excite, more or less, 

 nearly all the secretions, acting as a sialagogue, diaphoretic, expec- 

 torant, diuretic, and emmenagogue, in moderate doses ; and as an 

 emetic and cathartic in large doses. It is, however, chiefly 

 employed as a stimulating expectorant. It has been much used, 



