POWDERED DRUGS AND FOODS. 



795 



Almond meal consists chiefly of the tissues of the embryo. 

 The so-called almond meal which is used as a cleansing agent 

 consists of ALMOND CAKE, a by-product in the manufacture of 

 almond oil, to which are added other substances to give it a pleas- 

 ant odor, as orris root (see No. 247). A spurious almond meal 

 consists of wheat middlings to which powdered soap and some 

 volatile oil or triple extract are added. 



sp " 



Fig. 320. Orris root; pr, parenchyma containing starch grains; 

 with characteristic cleft; pr*, parenchyma with narrow oblique pores; 

 trachese; K, prisms of calcium oxalate, — After Vogl. 



•q> 



a, starch grains 

 sp, fragments of 



II. ABSENCE OF PLANT TISSUES. 

 A. SOLUBLE IN WATER. 



254. ACACIA (WHITE). — Soluble in cold water forming 

 a sticky mass; few plant tissues present (p. 643). 



255. SACCHARUM. — Crystals in rhombic prisms which 

 are insoluble in fixed oils, chloroform or ether, but soluble in 

 water, alcohol or glycerin. 



B. INSOLUBLE IN WATER. 



a. SOLUBLE IN ALCOHOL. 



256. CAMPHORA. — Liquefies in mounts of glycerin and 

 chloral; glycerin mounts show irregular masses, nearly insoluble 

 in water but soluble in alcohol, and fixed and volatile oils. 



