* 



i 



FOLIA DIGITALIS. 471 



tincture thus obtained was then mixed with basic acetate of lead as 

 long as it pi'oduced a precipitate. The latter being separated, the 

 filtered liquid was concentrated and the deposit now formed, after 

 some days, removed from the aqueous liquid. It was then washed 

 with a dilute solution of carbonate of sodium, by which a yellow matter 

 {chrysophan?) was partly removed. The substance was then dried, and 

 yielded to chloroform a brownish mass, which after the chloroform had 

 been driven off, was purified by benzin. This liquid dissolved the 

 remainder of the yellow or orange matter, and a little fat, leaving crude 

 digitoxin, which is to be purified by recrystalHzation from warm 

 alcohol, 80 per cent., adding a little charcoal This purification still 

 yields yellowish crj^stals, which ought to be washed again with car- 

 bonate of sodium, ether or benzin, and then recrystallized from warm 

 absolute alcohol, containing a little chloroform. This process, however, 

 will only afford colourless crystals provided it be so performed as to 

 cause the separation of digitoxin on account of the cooling of the 

 solution, not by the evaporation of the solvent. If the Hquid is instead 

 allowed to evaporate it will soon assume a darker coloration. In 

 the way just pointed out, perfectly colourless scales or needle- 

 shaped crystals of pure digitoxin are at length formed, the yield 

 being not more considerable than about one part from 10,000 of dried 

 leaves. 



Digitoxin is insoluble in water, to which it does not even impart 

 its intensely bitter taste as displayed in the alcoholic solution. _It is 

 likewise insoluble in benzin or bisulphide of carbon, very sparingly 

 soluble in ether, more abundantly so in chloroform, the latter liquid 

 however acting but very slowly on digitoxin. Its best solvent is 

 alcohol, either cold or warm. The composition of digitoxin answers to 

 the formula, C'''H'''0'. 



Digitoxin warmed with concentrated hydrochloric acid assumes a 

 yellow or greenish hue, the same which is commonly attributed to 

 commercial " dijjitalin." Digitoxin is not a saccharogenous matter ; in 



Toxiresin, an uncrystallizaVle, yellowish substance, which may easily 

 be separated on account of its ready solubility in ether; it appears to 

 oe produced also if digitoxin is maintained for some time in the st^te 

 of fusion at about 240° C. Toxiresin proved to be a very powertui 



poison, acting energetically on the heart and muscles of frogs. Ihe 

 yery specific action of foxglove is dne—not exclusively— to digitoxin 

 It IS so highly poisonous that Schmiedeberg thinks it not at all tit loi 

 "medicinal use, which might rather bo confined to other constituents ot 

 foxglove, as, for instance, to those obtained from the seeds under the 

 names of digitalin and digitalein. The latter, however, are ot moic 



tlifficult extraction than digitoxin. , ^ „ . ;, - ^^^,^tal 



^. The preparation of digitoxin is similar to that of 3 ahvelles crystal- 

 I'zed "digitalin;" the former as well as paradigitogenm aie largely 

 tound in Xativelle's digitalin. * . ,. „ ,, . 



, The Dlgifalin of Katlvdle-T:he researches on ^'g^talis of this 

 J^emist. for which the Orfila prize of 6000 francs was a mauled in 

 ^^r>, have resulted in the extraction of a crystallized piepaiation 



' A derivative of .liyltoa:m as extracted by Schmiedeberg from the seeds of foxglove. 



