VIRGINIA. SNAKE ROOT. 51 



of the infusion (3j to Oj boiling water) f3ij. Dose of the chcoction, 

 the same. The cold infusion is preferable, made with cold water, 

 acidulated with sulphuric acid, which more completely exhausts the 

 virtues of the bark, and gives a clear infusion. Dose of tincture, 

 f3j to f3iv. Biixam^s tincture (compound) contains also serpentaria 

 and other ingredients ; dose, the same. Dose of extract, 10 to 30 grs. 



Sulphate of Quiida. — Chemically a disulphate ; made by adding 

 dilute sulphuric acid to quinia, and crystallizing. Occurs in light, 

 feathery, white crystals, without odour ; taste bitter ; soluble in boil- 

 ing water and alcohol, and the dilute acids ; cold water freely dis- 

 solves it by the aid of sulphuric acid ; colour of the solution, opa- 

 lescent. 



Effects on System. — Generally similar to those of the bark, but 

 sometimes fails to cure intermittents, when the bark will succeed. 

 Dose, 10 to 14 grs., equivalent to 3j of good bark; ordinary dose, 

 one to three grains ; may be often given by enema ; also endermicaliy. 



Dose of the impure sulphate of quinia (made by evaporating the 

 mother waters), double that of the sulphate. Dose of sulphate of 

 cinchonia, the same as that of sulphate of quinia. 



The best substitutes for Peruvian bark are the salix, or willow,* 

 which contains a bitter principle, called salicin ; the barks of the 

 swietera febrifuga, the horsechestnut and the dogwood : the latter 

 contains a peculiar bitter principle, named cornine. 



^V^rLD Cherry Bark. — (Prunus Virginiana, U. S.) 



Bark of the P. Virginiana, an indigenous tree. The bark is taken 

 both from the stem and root ; comes in pieces several inches long, 

 slightly curved, usually deprived of the epidermis ; has a cinnamon 

 colour; taste, bitter and aromatic, with the flavour of the bitter 

 almond ; odour, similar ; active properties to water and alcohol ; in- 

 jured by heat. Active principles, hydrocyanic acid and a volatile 

 oil ; these do not pre-exist in the plant, but are the result of a re- 

 action between the amygdaline and emidsine with water. 



Effects. — A tonic to the digestive organs, and at the same time 

 sedative to the system. Useful in convalescence, attended with 

 irritability of the stomach ; also in the hectic of phthisis. 



Best given in cold effusion, made by macerating half an ounce in 

 a pint of cold water 24 hours ; dose, f 3ij three times a day. There 

 is also a syrup, which is an excellent preparation ; dose, f 3j. 



Virginia Snake Root. — (Serpentaria, U. S.) 



Root of the Aristolochia serpentaria, an indigenous herbaceous 

 plant, growing in rich woods. The root is perennial, consisting of 

 numerous long slender fibres, proceeding from a common caudex. 

 As found in the shops, it is in tufts of a brownish colour ; has a 

 strong camphorous odour, and a very bitter, acrid, camphorous taste. 



