516 VEGETABLE DHUGS 



Habitat. — Southern Europe and Asia; cultivated in 

 temperate climates. 



Description. — About 1 Mm. in diameter, almost globular, 

 with a circular hilum; testa blackish-brown or grayish- 

 brown, finely pitted, hard ; embryo oily, with a curved 

 radicle and two cotyledons, one folded over the other ; free 

 from starch ; inodorous when dry, but when triturated with 

 water, of a pungent, penetrating, irritating odor ; taste 

 pungent and acrid. 



Constituents. — 1, a glucoside, sinigrin (or potassium 

 myronate), and a ferment, myrosin. In the presence of water 

 the Jatter converts the former into the acrid, volatile, official 

 oil of mustard (allyl sulphocyanide, C3H5CNS), acid potas- 

 sium sulphate, and glucose ; 2, a fixed, bland oil, similar to 

 that in white mustard ; 3, gum. 



Dose. — Same as white mustard. 



Commercial form of mustard is a mixture of black and 

 white mustard, and constitutes Sinapis (B. P.) 



PEEPAEATION. 



Oleum Sinapis Volatile. Volatile Oil of Mustard. 



Synonym.— Olenm sinapis, B.P.; allyl sulphocyanide 

 (C3H5CNS), oleum sinapis sethereum.E.; essence de moutarde, 

 Fr.; setherisches senfol, G. 



Derivation. — A volatile oil obtained from black mfistard 

 by maceration with water and subsequent distillation. 



Properties. — A colorless or pale yellow, limpid and 



strongly refractive liquid, having a very pungent and acrid 



odor and taste; Freely soluble in alcohol, ether, or carbon 



disulphide, the solutions being neutral to litmus paper. 



Spec. gr. 1.018 to 1.029. 



Peepabation. — Linimentum Sinapis (B. P.); volatile oil of mus- 

 tard, camphoi- and castor oil. 



Action External. — Mustard quickly dilates the vessels 

 of the skin and causes hypersemia. If its application is 

 frequently repeated, there is so much vascular irritation that 

 transudation of serum occurs under the epidermis, and 

 blisters or bven pustules are formed. Mustard induces a 



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