Dr. Herapatli on the Cinchona Alkaloids. 61 



The residue contains the following : — 



I. II. III. IV. V. 



822 100-000 100-000 



which, with 2 atoms water, constitute the optical salt dried over 

 sulphuric acid at 62° Fahr., thus : — 



1 atom dry residue 822 



2 atoms water 18 



840" 

 and these results may be expressed by the following formula : — 

 C'- ff^N-OJj 2SO='HO + 5HO = 840, 



which appears to be the constitution of the optical salt dried at 

 62° Fahr. over sulphuric acid. 



From this it appears that the optical salt of quinine differs in 

 chemical atomic numbers merely in the possession of 1 atom less 

 iodine, the cinchonidine salt having 3, the quinine salt 2 atoms iodine ; 

 but in each case 2 atoms of sulphuric acid, and 5 water, with an 

 organic base of C^' H^* N" 0' common to both. How this is derived 

 from C" H=' N- O' in the one case, or C" H"^ N- O" in the other, it 

 is difficult to point out in the present state of the question. 



Were these \'iews correct, it might naturally be imagined that the 

 two salts may be mutually convertible. The author has undertaken 

 numerous experiments with this object in view ; and whilst he has 

 j)roved that it is possible (by boiling the quinine salt in spirit sur- 

 charged with iodine) to communicate th'e golden tint of the reflected 

 ray and tlie blue tint of the body-colour to the crystals on their 

 re-formation, yet this modified salt retains the crystallographic forms 

 of the true quinine salt ; whilst, by treating the cinchonidine salt by 

 spirit and aqueous sulphurous acid, that salt is modified also, 

 becomes fibrous in character, and assumes the red body-colour of 

 quinine salt, yet is at once to be distinguished from the true quinine 



