498 [March 19, 



possible of the quinidine-salt had been separated by concentration, 

 was treated by sulphuretted hydrogen to separate the antimony, and 

 was tested for potassa and for tartaric acid, both of which it was 

 found to contain. 



The reaction may therefore be represented by the following 

 equation : 



2 SbO, 



O bl H J C8 H 4 13 +|}c 8 H 4 12 



In order to confirm this view of the composition of the salt, some 

 acid tartrate of quinidine was prepared by taking a solution of tartaric 

 acid, dividing it equally into two portions, neutralizing the one with 

 quinidine, and then adding the other. This solution was then 

 boiled for some hours with excess of freshly-precipitated oxide of 

 antimony, filtered, and allowed to cool, when the same beautiful salt 

 made its appearance, identical in all its properties with the compound 

 formed by boiling tartar-emetic with quinidine. 



It will be obvious from these results that tartar-emetic, when 

 boiled with quinidine, undergoes a somewhat singular and unexpected 

 decomposition, neutral tartrate of potassa and the double tartrate of 

 quinidine and antimony being formed, while one-half of the antimony 

 of the original salt is precipitated as oxide. From this and the sub- 

 sequently to be described double tartrates, the tersulphide of anti- 

 mony which is precipitated has a light yellow or pale orange colour, 

 and, after being long washed with boiling water, still contains some 

 of the base, probably in the state of a salt. This portion of the 

 alkaloid may, however, be abstracted from the tersulphide of anti- 

 mony by digesting it with hot alcohol. 



In order to confirm the fact that the compound contained quini- 

 dine and not ^n altered base, as it may be observed from the analyses 

 given above that the carbon in the double tartrates is somewhat too 

 high, the antimony was removed from a portion of the salt by means 

 of sulphuretted hydrogen, the base precipitated by ammonia, well 

 washed with water, and crystallized out of spirit ; it was then obtained 

 with the^usual crystalline form assumed by quinidine, viz. 4 -sided 

 prisms, and gave the characteristic reaction with chlorine-water and 

 ammonia. A platinum-salt also was prepared in the usual way, 



