POLYGALA SENEGA. 
63 
pencil-shaped appendage ; the eight filaments are united at the base 
into two portions, and attached to the corolla ; the anthers are tubu- 
lar, and open at their summit ; the germen is oblong, and supports a 
simple erect style, crowned with a cloven stigma ; the capsule is 
obcordate, or inversely heart-shaped, and contains two small oblongs 
blackish seeds. 
This species of Polygala was introduced to the attention of the 
medical profession, about ninety years ago, by Dr. John Tennant, 
whose intercourse with the American Indians, led him to discover 
that they possessed a specific against the poison of the rattle-snake, 
which, in consequence of a suitable reward, was revealed to him, and 
found to be the root of this plant. 
Sensible and Chemical Properties. Rattle-snake root 
has little or no odour; when chewed, its taste is somewhat bitter, 
warm and pungent, and excites a peculiar tingling sensation in the 
fauces, which lasts for some considerable time ; these qualities 
reside in the bark, the central woody part being almost inert : both 
water and alcohol extract its active principles, (which appear to re- 
side in a resinous substance), but the latter most completely. The 
watery infusion is pale yellow, with a weak smell, but a strong taste 
of the root; sulphate of iron produces no change in the infusion. 
The active matter taken up by alcohol is precipitated from the 
tincture by the addition of water ; the ethereal tincture, on evapora- 
tion, leaves a similar substance. A peculiar vegetable principle has 
been discovered by Gehleu, in the roots of Senega, to which he gave 
the name of Senegin : this is obtained by treating the alcoholic ex- 
tract by ether and water, the former abstracting a certain portion of 
resin, and the latter some mucilaginous and saccharine matter. M. 
Peschier has also analysed the roots of Senega, and from six ounces 
separated one hundred grains of a peculiar alkaline principle, which 
he has named Polygalina ; this is united to a new acid, which he has 
denominated Polygaline : this salt he supposes to contain the active 
principle of the roots.* 
Medical Properties and Uses. This is a stimulating su- 
dorific ; in small doses it is expectorant and diuretic ; in larger doses 
emetic and cathartic. Soon after the introduction of this medicine 
as a specific for the bite of the rattle snake, it excited the attention of 
physicians as a remedial agent in the cure of many disorders. Dr. 
* It is probable the Senegin of Gehlen is identical with the Polygaline of M. 
Peschier. — Ed. 
