Dr. Herapath on the Cincliona Alkaluids. 65 



derived from a rhombic prism. The reflected tints are brownish- 

 olive, not unHke dead leaves, or brown beech -leaves. These crystals 

 are more doubly absorbent than either the quinidine or cinchouine 

 salt, but less powerfully optical as tourmalines than the quinine or 

 cinchonidine compounds. When polarized, they transmit a sienna- 

 brown body-colour if moderately thick, and thicker plates are bistre- 

 brown, but when sufficiently thick, they are wholly impervious to 

 plane-polarized light. The substance was not in sufficient quantity 

 to admit of any analysis. 



It is well known that quinine and quinidine, under the continued 

 effect of heat and dilute sulphuric acid, undergo a molecular change 

 into quiniciue, which M. Pasteur has asserted to be isomeric with 

 the original alkaloids, but hitherto no complete analysis has been 

 made of the metamorphosed alkaloids. 



The author has produced an iodo-sulphate of quiniciue, but it is 

 no longer a crystalline compound ; it presents itself as a deep blood- 

 coloured resin, very soluble in spirit and readily precipitated by water 

 from its spirituous solution. This substance has not yet been sub- 

 mitted to analysis. During the production of the iodo-sulphate of 

 quinidine a certain portion of the alkaloid becomes converted into 

 quiniciue, as may be demonstrated by the production of this resin- 

 ous compound from the mother-liquid on the addition of further 

 proportions of iodine. 



Cinchonine and cinchonidine become converted into cinchonicine 

 by similar treatment, and this amorphous alkaloid also forms a 

 resinous iodo-sulphate ; its colour is deep purple-black, and it 

 deposits itself on spontaneous evaporation of the spirit, or on the 

 cooling of a highly concentrated spirituous solution, in small drops, 

 highly tenacious at 100° Fahr., but becoming solid at 60° Fahr. 

 This compound has, in a fine state of division, a beautiful purplish- 

 blue colour, and such a film generally forms around the edge of the 

 vessel in which it is produced. 



Cinchonicine appears to be one of the products during the 

 manufacture of the iodo-sulphate of cinchonidine, but there is a 

 much larger production of it during the formation of the cinchonine 

 salt. 



From the foregoing reactions, the author appears to be justified 

 in asserting that eventually it will be found, when we know more 

 of the rational grouping of the constituent atoms of the vegeto- 

 alkaloids, that the construction of the formula for the cinchonidine 

 of Pasteur will have a much greater similarity to the arrangement 

 of the molecular groups of quinine than of cinchonine. And there 

 is also great probability that the grou[)ing of the atoms of cinchonine 

 and the quinidine of Pasteur will be found to present more points of 

 similarity ; but in each case he sees no reason to doubt the existence 

 of more oxygen in the cases of both quinine and quinidine than there 

 is in cinchonine and cinchonidine. lie also ventures to sns]iect that 

 cinclionicine and (punicine will eventually be found to contain more 

 carbon than the original alkaloid, the elements of water ])robably being 

 separated by the sulphuric acid during the process of formation. 



Phil. Mag. S. 4. Vol. IG. No. 10 i. July 18:»8. V 



