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BRITISH PHARMACEUTICAL CONFERENCE. 
looked so little like an active principle, and was so perfectly devoid of taste or 
smell, that I at once jumped to the conclusion that it could not be the thing 
I wanted. I therefore passed it over, as did my forerunner, Mr. Rau, without 
administering one dose even, and prosecuted my research in the liquid, from 
which, in combination with lead, it had been precipitated. The results, how¬ 
ever, were purely negative. 
I then macerated 33 oz. of Alexandrian senna leaves (unpicked) with 5 pints 
of methylated spirit, and, at the end of ten days, pressed and filtered. The 
spirit, a little water being first added to the liquid, was evaporated, and the 
resinous oily substance removed carefully from the aqueous fluid it overlaid. 
It was apparently destitute of medicinal activity,—the bitterness of the tinc¬ 
ture being concentrated in the fluid. Diacetate of lead added to this pro¬ 
duced an orange precipitate of certain colouring matters, of no pharmaceutical 
importance. The filtrate, freed from lead, was still bitter, but became less so 
on evaporation. During the process a dark-coloured resin separated. From 
the strong solution a little rectified spirit precipitated sulphate of ammonia and 
other salts, and then, twice its volume of ether being added, a dark-coloured 
sweet extractive was thrown down. The filtrate after evaporation, etc., was a 
second time so treated, and a second crop of extractive obtained. 
The ether-spirituous solution shaken with water, yielded to it a bitter sub¬ 
stance of dark colour and not unpleasant flavour. In doses of 5 grains it had 
no effect whatever on the bowels. The extractive was also inoperative. The 
bitter was doubtless derived from the Cynanchum, of which it may be said to be 
the active principle. 
The marc from which the spirituous tincture had been pressed was now' ex¬ 
hausted with water, and, from the infusion, purified from the senna acids by 
acetate of lead, the glucoside acid was precipitated with diacetate of lead. This 
compound having been decomposed with sulphuretted hydrogen and ammonia 
added, the glucoside was precipitated in combination with ammonia by rectified 
spirit. It remained now as a last resource to try its medicinal effect; not with 
much hope of result, but still acknowledging the possibility of this tasteless and 
apparently inert substance being so modified in its course through the system 
(bearing in mind also that senna acts only indirectly on the bowels), as to en¬ 
able it to produce the cathartic effect I desired to experience. On taking a 
dose of 5 grains, I was pleased to find that some disturbing effect was produced. 
A repetition of the experiment enabled me to decide that the glucoside was the 
active principle of senna. Flattering myself that I had made a discovery of some¬ 
thing not hitherto announced, I proceeded to prepare the glucoside by preci¬ 
pitating it directly from a concentrated infusion of senna, in combination with 
the bases—lime, magnesia, and potash, with which it is naturally associated. I 
found that the first precipitate was much contaminated with the senna acids in 
combination with lime, and was of little virtue ; the second precipitate was 
more active, and of this 4 grs. acted fairly as a purge. 
Just at this time I became aware of the existence of the paper on senna by 
Dragendorf and Kubly. It was pointed out to me by our President, who kindly 
sent me a resume of the work, translated from the German ‘ Quarterly Journal 
of Practical Pharmacy.’ It was now evident that as to the facts I had labori¬ 
ously discovered, I had been forestalled by the German professors. I therefore 
abstained from a minute examination of the glucoside, and devoted myself to 
attempting its preparation by a cheap and easy method adapted to the pur¬ 
poses of pharmacy. I must confess that my results hitherto have not been 
sufficiently good to warrant my enlarging at present upon my numerous expe¬ 
riments in that direction. I will give shortly, in conclusion, Dragendorf’s re¬ 
sults, adding a few remarks of my own on the pharmaceutical preparations of 
senna. 
