58 POWDERED VEGETABLE DRUGS 



and mealy, it indicates that the oil was removed previous to powdering. 

 If the powder is deficient in weight as compared with bulk or volume, 

 it indicates that winnowings or a poor grade of drug were used. 



The color of the powder is, of course, uniform and harmonizes 

 more or less with the predominating color of the crude drug, but it 

 must be remembered that the color varies greatly. For instance, 

 exposure to light deadens the color quite rapidly, the tendency being 

 toward grayish shades and tints. Exposure to moisture and the 

 presence of vegetable parasites, produces shade effects. The fineness 

 of the powders, also, greatly modifies the color, increased fineness 

 producing tint effects. In some instances the quality of the color .is 

 even changed; for instance, powdered licorice of medium fineness is 

 yellow, while the licorice meal is much lighter, with a decided lemon 

 tint. Roasting produces dark to nearly black colorations. Powders 

 made from plant parts rich in oil and fat, as cloves, almonds, larkspur, 

 stavesacre, etc., darken rapidly, and become rancid, due to the de- 

 composition of the fats into fatty acids and glycerin. 



Powdered vegetable drugs may be grouped according to the 

 following colors: 



I. Very Light. Mostly seeds and roots. 



1. White, as starches and cereal flour. 



2. Very light, tinged with yellow, red or some dark sub- 



stance; as althaea, orris root, colocynth, etc. 

 II. Yellow. Mostly roots and rhizomes. A few flowers and barks. 



1. Pale yellow and straw yellow. 



2. Orange yellow and lemon. 



3. Brownish yellow and yellowish brown. 



III. Green. Mostly leaves and herbs. 



1. Grayish green. 



2. Brownish green. 



IV. Gray. Mostly roots. 



1. Ash gray. 



2. Brownish gray and dark gray. 

 V. Brown. Mostly barks. 



1. Reddish brown. 



2. Dark brown. 



VI. Very dark. A few barks, as juglans. Roasted drugs. 



1. Very dark, tinged with red or yellow. 



2. Black, as charcoal. 



Since the gross characters of powdered vegetable drugs are variable 

 and otherwise inconstant and unreliable, the pharmacist must look to 



