BELLADONNA 



587 



hydrate, is the crystal layer, in which the cells filled with microcrys- 

 tals are grayish-black and somewhat larger than the surrounding 

 cells; non-glandular hairs few, uniseriate, 2- to 5-celled; glandular 

 hairs few, of two kinds, stalks 1- to 3-celled, glandular heads 1- to 

 many-celled; tracheae with annular, spiral, scalariform or reticulate 

 thickenings and with bordered pores; starch grains and pollen grains 

 few; occasional fragments of the stems having slightly lignified bast 

 fibers. 



Constituents. Several alkaloids amounting to from 0.3 to 0.7 

 per cent, of which hyoscyamine (see Hyoscyamus) exists in largest 



WW^v&33i 



FIG. 248. Belladonna root: Transverse section of a parenchyma cell filled with 

 sphenoidal microcrystals of calcium oxalate, the surrounding cells, which 

 are shown in part, contain starch grains. 



proportion. The drug also contains hyoscine (scopolamine), atro- 

 pine, formed from hyoscyamine, and belladonnine, formed from 

 atropine; a fluorescent principle /3-methyl-sesculetin (atrosin or 

 chrysatropic acid), which resembles a similar principle found in 

 gelsemium; malic acid and calcium oxalate in the form of sphenoidal 

 microcrystals (Fig. 248). 



Atropine (Fig. 251) is a powerful mydriatic alkaloid which occurs 

 in colorless or white acicular crystals that are soluble in alcohol but 

 sparingly soluble in water. It is optically inactive and may be 

 sublimed without decomposition. The aqueous solutions are, how- 



