486 Mr. Mann and Dr. Ince. [Feb. 14— Nov. 5, 



begun by one of them in 1897, and continued intermittently for some years ; 

 it was not till 1905, however, that a systematic examination of these plants 

 was commenced in the Government Laboratory. 



Isolation of the Alkaloid from the " York Road " Poison Plant, Gastrolobium 

 calycinum. Cygnme, C19H22N2O3. 



One pound of the powdered plant was extracted with 76-per-cent. alcohol, 

 rendered slightly acid with acetic acid. The bright green percolate was 

 evaporated at 50° O, and the residue treated with 1-per-cent. sulphuric acid, 

 filtered and the filtrate cleared with lead acetate, the excess of lead being 

 removed by means of sulphuretted hydrogen. The cleared solution was 

 neutralised and precipitated with tannic acid, the precipitate was collected 

 and mixed with freshly prepared lead hydrate. This mixture was then care- 

 fully dried below 50° C. and extracted with hot 70-per-cent. alcohol. The 

 alcoholic solution was evaporated and made acid with hydrochloric acid. 

 From the solution a crop of colourless crystals separated. These were 

 purified by re crystallisation. On injection into a guinea-pig, however, they 

 exhibited no toxic action. 



In the next experiment 10 lb. of the powdered plant were extracted with 

 alcohol and treated as before, but with this difference, that in none of the 

 operations was the temperature allowed to rise above 30° C. 



The result was an indefinite crystalline mixture that under the micro- 

 scope consisted of needle-shaped and cubical crystals. These were separated 

 by careful solution in alcohol and evaporation in vacuo. (The cubical crystals 

 are only slightly soluble in alcohol.) By this means a hydrochloride that 

 crystallised in fine acicular crystals was obtained. That it possessed toxic 

 properties was proved by the fact that one-tenth of a grain killed a guinea- 

 pig in seven minutes. The cubical crystals, mentioned above, were often met 

 with in later investigations ; they are colourless, very soluble in water, but 

 only slightly so in alcohol. They contain no nitrogen or chlorine and possess 

 faintly acid properties. The mean of two analyses gave : — C = 68'7 and 

 H = 8-1. Calculated for Ci 2 Hi 6 3 , C = 69'2, H = 7*7. It seems probable 

 that this substance is a decomposition product of the alkaloid, for whenever, 

 during the extraction of the plant, a high temperature (100° C.) had been 

 used for evaporation, the cubical crystals either preponderated or were the 

 only crystalline substance obtained. Moreover, on warming the acicular 

 crystals with water, for the purpose of recry stall isation, the result was 

 always the same, an increasing crop of the cubical crystals and a non- 

 crystallisable brown substance. 



The acicular crystals were the hydrochloride of a nitrogenous substance, 



