SINAPIS NIGRA 



209 



yellow (white) or brownish-yellow (black) oil, of a bland taste. This oil is 

 a commercial oil and not infrequently used for the adulteration of other oils. 

 Rapeseed, or colza, oil is obtained from the seeds of different varieties of the 

 genus Brassica, rape (Brassica napus) in particular. In Europe the term 

 rapeseed oil is sometimes applied to the product of rape alone, colza being 

 restricted to the oil obtained from the ruta-baga, or Swedish turnip (B. 

 campestris), while "Rubsen" oil is furnished by the common turnip (B. rapa). 

 There is great confusion among authors in the use both of the common names 

 of the oils and the scientific names of the varieties of Brassica which produce 

 them. The seeds of rape contain from 33 to 43 per cent, of oil, which, when 

 crude, is a dark yellow-brown and used for lubricating. Refined and freed 

 from albumen and mucilage the oil becomes bright yellow. Rape oil is ex- 

 tensively used for lamps, lubricating machinery, and for adulterating both 

 almond and olive oils. 



FIG. 108. Sinapis nigra Branch. 



190. BURSA PASTO'RIS. SHEPHERD'S PURSE. The herb ofTCapsel'la bursa- 

 pastoris Moench, a small plant very common along ourjroadsides. Itjderives 

 its name from its inversely heart-shaped fruit in elongated racemes. The 

 small white flowers are in corymbose racemes. Nearly inodorous ;^taste acrid, 

 pungent, and bitter. Contains a little volatile oil of mustard. Anjactive 

 diuretic, also tonic and stimulant. Dose: 15 to 60 gr. (i to 4 Gm.). 



191. ARMORACIA. HORSERADISH. The root of Cochlea'ria armora'cia Linne"- 

 Indigenous to Europe, but cultivated in our gardens as a condiment. A 

 cylindrical root 300 mm. (12 in.) long, 12 to 25 mm. (% to I in.) thick; ex- 

 ternally pale yellowish-brown, warty; internally white; fracture short; odor 

 when crushed pungent ; taste sharp and acrid. Contains a volatile oil similar 

 to oil of mustard. Used only in fresh state as a stimulant to digestion, as a 

 diuretic, and externally as a rubefacient. Dose: I to 2 dr. (4 to 8 Gm.). 



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