POWDERED DRUGS AND FOODS. 785 



222. LUPULINUM.— Reddish-brown (Fig. 298) ; large, 

 characteristic glandular hairs about 20 /* in diameter. In fresh 

 Lupulin there are more light yellow glandular hairs than in old; 

 In the latter there are browner or grayish-brown resinous masses 

 replacing the light yellow oil. The amount of Humulus frag- 

 ments should not be too large in Lupulin of good quality. 



223. OPIUM.— (See No. 197.) 



224. ROSA GALLICA. — Rose-colored ; epidermis with acute 

 papillae; pollen grains few, broadly spherical, 30 /* in diameter 



(P- 557)- 



225. ROSA CENTIFOLIA.— Pollen grains nearly smooth 

 and elliptical, from 15 to 30 /u, long; fragments of corolla pinkish 

 with chloral ; papillae of corolla somewhat rounded ; cells of 

 anther; long, i -celled, non-glandular hairs around ovary. A 

 hydro-alcoholic solution becomes yellowish-red with acids. 



226. ZEA. — Style with spiral and annular tracheae ; numerous 

 non-glandular hairs consisting of 2 parallel rows of cells, and 

 from 0.5 to I mm;~4oHg (p. 558). 



POWDERS OF A WHITISH APPEARANCE. 



This group includes all those powders which are light in color, 

 and comprises chiefly the commercial starches, cereals, gums and 

 some of the inorganic substances which are occasionally used as 

 adulterants. 



I. PLANT TISSUES OR CELL-CONTENTS RECOG- 

 NIZABLE. 



A. CONTAINING STARCH. 



a. ONLY UNALTERED STARCH GRAINS PRESENT. 



Grains characteristic for each; completely soluble in glycerin 

 on heating, and precipitated on the addition of alcohol, the pre- 

 cipitate being soluble in water. 



227. ARROWROOT STARCH.— There are a number of 

 commercial kinds of this starch, depending upon the countries in 

 which it is produced (p. 244). Bermuda arrowroot is in the form 

 of somewhat hard, irregular granules or masses, varying from 



50 



