624 



SCIENTIFIC AND APPLIED PHARMACOGNOSY 



the preparation shall give a green color when dissolved in concen- 

 trated sulphuric acid, whereas commercial digitoxin gives a brown 

 color on solution. 



Digitalin (digitalinum verum) is a heart stimulant and yields on 

 hydrolysis digitalose and digitaligenin. It occurs in white, rather 

 characteristic granules which are sparingly soluble in water and more 



FIG. 276. Digitalis: a, surface view of upper epidermis, showing slightly undu- 

 late walls; b, lower epidermis, the cells having distinct undulate walls, 4 

 stomata also being shown; c, a uniseriate non-glandular hair; d, several 

 forms of glandular hairs; /, section of portion of xylem, showing tracheae 

 having simple pores (p), reticulate thickenings (r), annular markings (I) 

 and spiral thickening (e). 



or less soluble in alcohol, forming yellowish-colored solutions with 

 concentrated hydrochloric or sulphuric acids. If the latter acid 

 contains a trace of ferric sulphate solution a permanent bluish-red 

 color is produced. 



