124 M. A. Strecker on the Constitution of Quinine. 



silver a crystalline precipitate which dissolves in boiling water. 

 When this solution is allowed to cool, it forms a pasty mass, 

 which in course of time becomes converted into colourless cry- 

 stals. These crystals are a compound of quinine and nitrate of 

 silver ; they are soluble only in 300 parts of cold water. Ana- 

 lysis leads to the formula C^ H*^ N^ O^ . AgO . NO^ 



As regards the equivalent of quinine, some chemists represent 

 it by the formula C^H^^NO^ whilst others think it is rather 

 Q40 JJ24 jyf 2 Q4 Accordiug to the first formula, neutral sulphate 

 of quinine is C^OH^^NO^ HO . SO^; and the other sulphate, 

 ^40 H24 N2 04 HO . S03, must be a basic sulphate. According 

 to the second formula, it is the latter salt that is neutral, and 

 the sulphate C^o H^^ NO^ 110 . SO^ is an acid salt which ought 

 to be represented by the formula C^^ H^^ N« 0^ 2H0 . 2S9^ 



There are other chemists, again, who represent the equivalent 

 of quinine by C^ H^^ NO^, but regard the molecule of this alka- 

 loid as composed of two equivalents, or as C"^ H^'* N^ O'*. 



From the facts hitherto known, there appeared to be no very 

 conclusive reasons for adopting one of these formula3 in prefer- 

 ence to the other, but I think that the following results will 

 enable us to settle the equivalent and molecule of quinine. 



A mixture of iodide of scthyle and quinine dissolved in ajther 

 and left for a few hours, furnishes crystals which increase in 

 quantity with time. These crystals dissolve with facility in 

 boiling water, and separate again on cooling, in the form of long 

 acicular crystals arranged round a common centre. They are 

 colourless, silky, and of a bitter taste ; they lose no water at 

 212° F., and fuse at a higher temperature without decomposi- 

 tion. The analysis of these ciystals showed a composition ex- 

 pressed by the formula C^ H^^ N^ 0^ I, or in 100 parts,— 



Found. Calculated. 



Carbon . . 55*0 54*8 55-0 



Hydrogen . 62 6*2 6-0 



Iodine . . 26-4 26-5 



The formation of this compound, which I name iodide of 

 aethylo-quinine, is explained by the following equation : — 



C40 H24 N2 04 -f C4 H5 1 = C44 H^ N2 04 1. 



An analogous compound is obtained with iodide of methyle, 

 which I call iodide of methylo-quinine ; its composition is ex- 

 pressed by the formula C^^ H^^ N* 0^ I ; its analysis gave — 



Found. Calculated. 



Carbon . . . 542 541 



Hydrogen . . 5*9 5-8 



Iodine . . . 269 27*2 



