36 ON DIGITALIS, WITE SOME OBSERVATIONS ON THE URINE. 



Digitalic Acid. — White, crystallisable, and of an acid taste 

 and peculiar odour, becoming suffocating under heat, soluble in 

 water and alcohol, slightly in ether, decomposes in air, and 

 becomes brown with extreme facility : the decomposition being 

 favoured by light and alkalis. 



Antirrliinic Acid. — This is volatile and oily in appearance. 

 Besides these, there are Digitaloic Acid, Tannic Acid, Sugar, 

 Pectin, an albuminoid azotised matter, a crystallisable orange- 

 red colouring matter, chlorophyll, a volatile oil, and ligneous 

 fibre. 



The process they employed for the extraction of digitaline, 

 was to precipitate a watery infusion of digitalis by subacetate 

 of lead, to remove the excess of lead by a mixture of carbonate 

 and phosphate of soda, and the lime by oxalate of ammonia. 

 To the filtrate they added tannin, and the product of this was 

 mixed with litharge, dried, powdered, and treated by alcohol. 

 This was then evaporated, and the residue was treated with 

 concentrated ether, which dissolved the other principles and left 

 the digitaline. This process, as modified by 0. Henry, and 

 adopted in the British Pharmacopoeia, consists in treating the 

 syrupy alcoholic extract with acetic acid, decolorising by animal 

 charcoal, precipitating by tannin, decomposing by litliarge, and 

 thus freeing the digitaline which is decolorised by animal 

 charcoal and purified by ether. 



The composition of digitalis has been examined by many 

 other chemists, especially Radig, Morin, Buchner, Kossman, 

 and Walz. 



Walz* has obtained as volatile principles digitalosmin and 

 digitalissic acid (valeric acid), and as non-volatile principles 

 digitalin, digitasolin, digitalacrin, digitaloin, and digitaloic acid. 

 Digitalosmin is the odoriferous principle of digitalis, and is a 

 camphoroidal substance obtained as a fatty film by distilling 

 with water. When the crude digitaline, obtained after decom- 

 posing the tannin precipitate with litharge, is treated with ether 

 to purify it, an acrid matter is dissolved, to which Walz at first 

 gave the name of digitalacrin, thinking it a simple substance ; 

 but has since found that from it may be separated digitaline 



* Watt's Diet. Ckem., Art. "Digitalis." 



