a newly-discovered Salt of Quinine. 163 



Ammonia rapidly decomposes them ; this power is greatly in- 

 creased by heat. A colourless solution results, and an opake 

 Naples-yellow precipitate remains, which is fusible at the boiling 

 temperature of the ammoniacal liquid. A deep brownish-yellow 

 resinous mass results ; this is a compound of iodine and the 

 alkaloid. 



Liquor potassa? has the same action on these crystals ; but the 

 resulting resin is deeper in colour, being now a chocolate-brown. 



The alkaline solutions in both instances contain sulphuric and 

 hydriodic acids. 



Analysis. — About ten grains of the mixed di sulphates of qui- 

 nine and cinchonine were dissolved in half an ounce of pyrolig- 

 neous or acetic acid ; into the hot solution was dropped a spi- 

 rituous solution of iodine (without iodide of potassium) ; as the 

 mixture cooled, these little gems gradually formed ; they were 

 carefully separated on a filter, and again dissolved in acetic acid 

 by the aid of heat ; a few drops of the tincture of iodine, as be- 

 fore, added, and on cooling they were again deposited ; a second 

 recrystallization removed all traces of impurity ; they were col- 

 lected on a filter and dried. 



(A.) About three grains of these purified acetic crystals were 

 redissolved in acetic acid, and whilst the solution was hot, acetate 

 of baryta was added ; a white precipitate was immediately pro- 

 duced ; this was insoluble in concentrated nitric acid, and proved 

 to be sulphate of baryta. [The acetic acid used in this experi- 

 ment gave no trace of sulphuric acid when tested in the same 

 way.] 



(B.) Into the filtered portion from A (the excess of baryta 

 having been removed by a solution of sulphate of ammonia and 

 again filtered) were dropped nitric acid and then granules of 

 starch ; an abundant indication of the presence of iodine was 

 instantly made evident. 



(C.) Into the fluid filtered from B was dropped solution of 

 ammonia; a flocculent, white, gelatinous precipitate was pro- 

 duced j this separated and fell to the bottom after some delay. 

 Upon agitating the mixture with sulphuric aether, the precipitate 

 was dissolved, and separated by decanting the sethereal solution 

 from the watery fluid j upon slowly evaporating the sether by 

 exposure to the air, a gummy resinous mass remained, nearly 

 destitute of colour and crystalline appearance; it was probably 

 quinine, as it did not crystallize. 



Other experiments were instituted to decide the question 

 whether the alkaloid was quinine or ciiiehoniiic. 



1st. By taking Advantage of the different solubility of the two 

 diaalpbatet, tin ) were separated, and at length rendered perfectly 

 pure. 



M2 



