16 MEDICINAL PLANTS 



Rhus Toxicodendron, Linn., (Poison Oak, Poison Ivy). The 

 radicans is a variety of this species ; its medical properties resemble 

 those of the mix vomica; acts upon the motor tract of the spinal cord ; 

 hence has been used in paralysis ; also in rheumatism and cutaneous 

 diseases, as an alterative. Dose of powder, gr. ss., gradually increas- 

 ed till some effect is produced. The active principle is so volatile that 

 it cannot be given in decoction or extract. The juice is yellowish and 

 milky ; becomes permanently black on exposure to air, and when ap- 

 plied to linen or cotten forms an indelible dye, not subject to fade, nor 

 eradicable by chemical agents. All vegetables which possess poison- 

 ous properties contain a similar principle of a peculiar character. All 

 the plants belonging to the above order have a resinous, gummy, or 

 milky caustic juice, though their fruit is often edible and pleasant. The 

 West India Mango belongs to it. 



XanthoxvlacejE, Juss. — (The Prickly Ash Tribe). 



Zanthoxylum* Americanum, Mill., (common Prickly Ash). This 

 well-known shrub possesses medicinal properties almost identical 

 with those of the mezereon and guaic, and might often be substituted 

 for them in the same complaints, with advantage. Stimulant, diapho- 

 retic, deobstruent ; used chiefly in chronic rheumatism and cutaneous 

 diseases. Dose of powder, gr. x. to 3 j. ; decoction, boil sj. of bark in 

 O.iij. water to one quart, and give from 3 iv. to § xij. in a day. Con- 

 tains a peculiar crystallizable principle, zanthoxylin, to which its vir- 

 tues are owing. Besides this, it contains fixed oil, resin, gum, and co- 

 loring matter. The whole plant is endowed with active properties, 

 though the bark only is officinal. This is acrid, pungent and aromatic. 



Ptelea"|" Trifoliata, Linn., (Swamp Dog-wood, Stinking Ash). 

 A strong infusion of the leaves and young shoots of this plant, are said 

 by Schoepf, to be anthelmintic ; the fruit is aromatic and bitter, and 

 forms a good substitute for hops. 



Hippocastinace^:, Be Cand. 



The Horse Chestnut Tribe furnishes us but one genus, the 

 jEscalus Hippocastinum, (Horse Chesnut), a native of Asia, but culti- 

 vated as a shade tree, both in this country and Europe. Fruit and 

 bark have been used in medicine. The former abounds in starch, but 

 has a rough, disagreeable, bitter taste ; of which it may be deprived 

 by maceration in an alkaline solution. The starch is readily separat- 

 ed, and equal at least to that obtained from the potato. The powder- 

 ed kernel of the fruit is a useful sternutory, in diseases of the head and 



* From the Greek, xanthos, yellow, and xylon, wood. 



+ The Greek name of the Elm, from ptao, to fly, in allusion to the winged seed 

 Tessels. 



