CRUDE DRUGS. 



609 



senna-chryosphanic acid (di-oxymethylanthraquinone). (See 

 Rhubarb.) Anthraglucosennin when acted upon by alkalies pro- 

 duces an amorphous black powder, sexxa-nigrix, which also 



Fig. 263. Cassia angustifolia (India senna): A, transverse section through the 

 middle vein showing upper epidernais (E), palisade cells (P), rosette aggregate of calcium 

 oxalate (Odl , monoclinic prisms of tfalcium oxalate (o) , tracheas (G) , sieve (Sg) , sclerenchyma 

 fibers (F). lower epidermis with rather thick-walled cells (E). B, transverse section through 

 portion of leaf between the veins showing the absence of monoclinic prisms of calciuni oxa- 

 late, the presence of palisade cells and stomata in both the lower and upper portion, and 

 a hair (H) on the lower surface. C, lower epidermis on surface view; D, upper epidermis 

 showing stomata and a single hair. E, diagram of section through the middle vein, the 

 letters corresponding to those in A. — After Meyer. 



yields on hydrolysis emodin and chrysophanic acid. Senna also 

 contains a yellowish, amorphous glucoside, glucosennin ; a red- 

 dish-brown, amorphous substance, senna-rhamnetin^ which dif- 



39 



