6i6 BOTANY AND PHARMACOGNOSY. 



digitalis and a nauseous, acrid taste; a volatile principle, antir- 

 rhinic acid, somewhat resembling valerianic acid; digitalic acid, 

 separating in white needles ; two coloring principles, one red and 

 the other yellow, resembling chrysophan, a glucoside found in 

 rhubarb ; an oxydase ferment which occurs in the recently dried 

 leaves; and ash lo to i6 per cent, (see Fig. 335). 



DiGiTOXiN occurs in white, needle-shaped crystals which are 

 insoluble in water but more or less soluble in alcohol, of a bitter 

 taste and colored deep green with hydrochloric acid. Digitalin 

 (digitalinum verum) occurs in white, rather characteristic gran- 

 ules which are sparingly soluble in water and more or less soluble 

 in alcohol, forming yellowish-colored solutions with concentrated 

 hydrochloric or sulphuric acid. If the latter acid contains a trace 

 of ferric sulphate solution a permanent bluish-red color is pro- 

 duced. DiGiTONiN is a saponin-like crystalline substance which 

 is nearly insoluble in water, somewhat soluble in alcohol, and 

 remains colorless on treatment with hydrochloric acid, but a dilute 

 sulphuric acid solution becomes garnet-red in color on boiling 

 for some time. Digitalein occurs as a yellowish-white powder 

 and is supposed to be a mixture of digitoxin, digitalin and digi- 

 tonin. French digitalin consists chiefly of digitoxin, while in 

 German digitalin the principal substance is digitonin. The 

 latter is distinguished by being more soluble in both water and 

 alcohol. Digitin is a physiologically inactive substance. Nati- 

 velle's digitaline cristallisee consists chiefly of digitoxin. 



Allied Drugs. The seeds of Digitalis purpurea are about 

 I mm. or less in diameter, yellowish- or dark-brown, oblong or 

 spatulate in section, more or less plano-convex and somewhat 

 tuberculate. They contain apparently the same principles as the 

 leaves. The digitoxin is said to be different from that obtained 

 from the leaves and is known as a-digitoxin. It is claimed that 

 the leaves of the first year's non-flowering plant when properly 

 dried are equally as active as the official leaves. 



The leaves of Digitalis grandiflora growing abundantly in 

 Switzerland appear to be as efficient as those of Digitalis purpurea. 



Adulterants. The leaves of other cultivated varieties of 

 Digitalis have been substituted for those of D. purpurea, as those 

 of the Mammoth Foxglove (D. monstrosa), which is distin- 



