BY JAMES M. PETRIE. 1 47 



baryta, evaporated, and heated to constant weight. The barium 

 salt was then decomposed by sulphuric acid. 



0-7065gm. Ba salt gave 0-645 gm. BaSO^ =53-73% Ba; barium 

 acetate requires 53-73% Ba. 



The acid is, therefore, acetic acid alone. A part of the dis- 

 tillate was titi'ated with xt alkali, and from this, the amount 

 of acetic acid in the whole distillate was found. 



Total acetic acid 1-7 gms. = 0-01% of the bark. 



= 2-27% of the volatile oil. 



This acid is doubtless formed during the steam-distillation, by 

 the partial hydrolysis of acetic esters existing in the original oil. 



C. The Rksins. 



After the steam-distillation, the residue in the retort was 

 removed while hot, and consisted of aqueous solution and a thick 

 oily semi-solid mass. The latter, containing the resins and fixed 

 oils, was washed repeatedly with hot acidulated water, and in 

 this way the greater part of the alkaloid present was obtained in 

 solution. The solid residue was dissolved in alcohol, and poured 

 into a large volume of water. The sediment which settled was 

 separated and dried. 



Its weight was 350 gms., or 1-9% of the bark. 



D. The Alkaloid. 



The aqueous solution containing the washings from the resins 

 was concentrated to about 9 litres. This solution was treated 

 with lead acetate, and then basic acetate, the precipitates being 

 removed and washed. The filtrate, free from lead and hydrogen 

 sulphide, was now concentrated to 4 litres, and the alkaloid 

 separated by ammonium hydroxide. The voluminous alkaloidal 

 precipitate being filtered off, the solution still contained alkaloid ^ 

 which was then recovered by shaking with chloroform, and 

 uniting it to the main precipitate. 



Purification. —The crude alkaloid was now dissolved in dilute 

 sulphuric acid, and precipitated with mercuric potassium iodide. 

 From this, after careful washing, the alkaloid was recovered ; it 

 was then precipitated three successive times with ammonia, and 



