186 MEDICAL BOTANY. 



nix, with which it was at one time confounded ; this varnish is also procured 

 from the R. sinense, and R. succedaneum, both natives of China and Japan. 



Another group of the genus possesses wholly different properties, the species 

 comprising it being astringent and tonic, and wholly destitute of poisonous 

 qualities. Thus the R. coriaria and R. cotinus, have been used as substi- 

 tutes for Cinchona, and as astringents in bowel complaints, whilst their leaves, 

 especially those of the first, are largely employed in the tanning of Morocco 

 leather, as are also those of our native species, the R. copallinum, glabrum 

 and typhinum. 



The R. glabrum is recognised as officinal in the secondary list of the 

 United States Pharmacopoeia. It is a shrub from four to twelve feet in height, 

 with large pinnate leaves, and large, erect, terminal thyrses of greenish-red 

 flowers, succeeded by clusters of crimson berries, covered, when mature, with 

 an acid efflorescence. These berries have a sour, astringent taste, and are 

 often used for the purpose of making a kind of vinegar. They owe their 

 acidity to the presence of malic acid, and an infusion of them has been re- 

 commended as a cooling drink in febrile complaints, and a gargle in affections 

 of the throat ; but from the observations of Dr. Fahnestock, it appears that 

 the inner bark of the root is possessed of much higher powers; he states that 

 an infusion of it is almost a specific in the sore mouth resulting from mercu- 

 rial salivation. 



The R. copallinum was at one time supposed to afford one of the resins 

 known under the name of Copal, but this idea is erroneous as far as regards 

 the species as existing in the United States, for although it certainly exudes a 

 resinous juice, this is in very small quantity, nor does it harden like the true 

 copal ; in Mexico, where it is said to be procured, the case may be dif- 

 ferent, as it is well known that the same plant may furnish a large quantity of 

 resinous juice in one climate and be almost destitute of it in another; thus 

 the Liquidambar abounds in the balsam of that name in Louisiana, but is very 

 deficient in it in Maryland and Pennsylvania. 



The leaves and berries of these species are much used by the Indians to 

 mix with, and as a substitute for tobacco for smoking. 



The R.metopium, a West India species, furnishes a gum known as " Doc- 

 tor's gum," which, in large doses, is emeto-cathartic, and is said in smaller 

 ones, to be a useful remedy in disorders of the bowels and respiratory organs. 

 The mode in which it is given is to mix a spoonful of the fresh juice with two 

 ounces of boiling water ; the dose is a teaspoonful occasionally. {Jam. Phys. 

 Jour.) Descourtilz (Flor. Med. Antill. ii. 49) states that the bark is an ex- 

 cellent astringent. The R. coriaria is also a powerful astringent, and is used 

 in tanning leather ; its acid fruits are employed in Turkey to form vinegar. 

 The R. cotinus furnishes most of the Sumach of commerce, and its wood is 

 the basis of a bright-yellow dye. 



Pista cia. — Linn. 



Flowers dioecious, apetalous. Males, calyx 5-clcft ; stamens five ; anthers almost ses- 

 sile. Females, calyx 3-4-cleft ; styles three. Drupe 1-seeded. 



This genus contains about a dozen species, all of which are trees or shrubs, 

 affording a resinous juice, and having alternate, winged, or trifoliate leaves. 

 They are principally natives of countries bordering on the Mediterranean, 

 where some of them are cultivated for the sake of the nut, which is edible, 

 and affords a bland oil. 



1. P. lentiscus, Linn. — Leaves abruptly pinnate ; leaflets ovate lanceolate. Petiole 

 winged. Flowers racemose. Segments of the calyx ovate, shorter than the stamens. 



