142 SOME POISONOUS PLANTS IN N.O. SOLANACE.E, V., 



alkaline with a very slight excess of ammonia, which separated 

 the alkaloids in a dense white precipitate. The alkaloids were 

 then removed in solution by agitating repeatedly with equal 

 volumes of chloroform. The chloroform was removed by dis- 

 tilling under diminished pressure, when there was left in the 

 flask a semi-solid mass, which, after standing some days, crys- 

 tallised in beautiful white radiating needles. 



The original plant-material was not treated in one large bulk, 

 but in a number of small portions as required. In one of these, 

 which yielded the maximum weight of alkaloids, the following 

 data were recorded : — 300 gms. of air-dried plant extracted for 

 24 days altogether. The aqueous extract was concentrated to 

 350 CCS., and precipitated with one litre of Wagner's decinormal 

 iodine solution. Ether removed from this acid solution about 

 2 gms. of impurities, and chloroform from the alkaline liquid 

 yielded 5 gms. of crude alkaloid. A portion of the latter in 

 solution was titrated with decinormal acid and iodeosin indicator, 

 and the result showed that 81 per cent, consisted of pure alkaloid. 

 The yield was, therefore, 1*42 per cent, of alkaloids in the dried 

 (at 100°C.) plant-leaves, or 0*28 per cent, in the fresh plant. 



The optical activity of a solution of this crude alkaloid in 50 

 per cent, alcohol was determined, [ajo — 18°. 



(A.) Sepai'ation of the Alkaloids: — The mixed alkaloids were 

 converted directly into aurichlorides, by the addition of gold 

 chloride to the solution of alkaloids in dilute hydrochloric acid. 

 The yellow precipitate was dissolved in sufficient warm water, 

 and set aside to slowly crystallise spontaneously. At regular 

 intervals, the crystals were removed by decanting the superfluid. 

 These crystals were washed and the melting-points determined, 

 then redissolved in dilute hydrochloric acid and again set aside 

 to crystallise. After a long and tedious process of fractional 

 crystallisation, the various fractions being placed together, or 

 separated, according to their melting-points, the latter were 

 observed to concentrate near certain definite temperatures. 

 These fractions were finally obtained with melting-points which 

 did not change after further recrystallisation. A summary is 



