68 



cloudiness, throw down the lead in solution by sulphuric acid, 

 neutralise with ammonia, precipitate with tannic acid, mix the 

 washed deposit with hydrated lead oxyd, dry, exhaust with 

 alcohol, decolourise (if necessary) with animal charcoal, and 

 evaporate. — Yellowish, amorphous mass, very bitter, fuses at 137* 

 and is destroyed in higher temperatures, dissolves in 125 parts 

 cold and in 42 parts hot water, in 2^ parts cold and in 1| parts 

 hot alcohol, in 20,000 parts cold and in 10,000 parts hot ether, in 

 80 parts chloroform, breaks up when boiled with diluted acids, 

 into sugar and two other pi'oducts. 



[Dig'italill, crystallised =050 H40 O30. Alkaloid, discovered by 

 C. A. Nativelle in the herb of Digitalis purpurea, gathered in 

 spring. To pi'epare it, add to 100 parts of the coarsely pulverised 

 herb 25 parts acetate of lead and 100 parts water, and after 

 twelve hours exhaust with water in a displacement apparatus. 

 The residue is exhausted with 300 parts of proof spirit, and to the 

 liquid is added a solution of 4 parts phosj)hate of soda. 

 Remove the precipitate by filtering and drive off the spii'it by 

 distillation on a water-bath. By evaporating the residue on a 

 water-bath to about one-tenth, a pitch-like mass is obtained, 

 which is washed with water and left on blotting-pajier to diy at 

 the ail'. The two or three pai-ts of the pitch-like body, obtained in 

 this way, are dissolved in double their quantity of alcohol of 

 60°/q and allowed to stand until yellow radiated crystals have 

 formed, together with tliose of an inactive body. Separate the 

 crystals from the mother-ley and wash with alcohol of 35% 

 to remove the inactive ])rinciple. Dissolve the remaining crystals 

 in boiling alcohol of 80^/^, boil a few minutes with animal 

 charcoal, filter, evaporate half the alcohol and allow to crystallise, 

 Sejiarate the crystals from the mother-ley and dry over a water- 

 bath. Finely j^ulverise the crystals and shake strongly with 20 

 parts chloroform pure and especially free fi'om alcohol. After 

 twenty-four hours filter and distil to dryness. The remainmg 

 yellow Digitalin is dissolved in alcohol of 80°/^, boiled with a little 

 washed animal charcoal and crystallised. After rej^eatiug the 

 latter process several times, the Digitalin is obtained pure. — D. is 

 neutral, without odour, of an intense, lasting bittei'ness. It 

 dissolves in chloi'oform in every pro})örtion ; in twelve parts cold 

 and six parts boiling alcohol, not so well in absolute alcohol. Ether, 

 benzol and water dissolve only traces. Sulphuric acid dissolves 

 it with green colour which turns to a light-red through vapour 

 of bromine and becomes green again on addition of water. 

 Nitric acid dissolves it without coloui-ation, but soon changing to 

 yellow. Hydrochloric acid dissolves it with gi'een-yellow colour, 

 turning slowly to an emerald green. Heated above 100° it 

 becomes very elastic ; heated on platinum-foil it melts without 

 colouration to a transparent mass, evolves copious white vapours. 



