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 al:mond 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. 



-fP 



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

 with characteristic cleft; pr', parenchyma with narrow obhque pores; sp, fragments of 

 tracheae; K, prisms of calcium oxalate. After Vogl. 



11. 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. 



