Q2 Royal Society : — 



salt even by the naked eye alone ; and on redissolving these in 

 spirit, the hhic body-coloured salt again recrystallizes with its ordi- 

 nary <'oldcn reflected tint. The effect of diluted sulphuric acid in 

 converting the cinchonidine salt into the golden silky fibrous variety, 

 is a striking distinguishing characteristic between the two alkaloids. 



These facts lead to the conclusion, that the grouping of the con- 

 stituent molecules in the two salts differs materially ; that closely as 

 the quinine and cinchonidine salts agree amongst themselves, they 

 differ widely from the quinidine and cinchonine compounds. * 



The quinidine salt, after recrystalhzation, presents itself as long 

 quadrilateral acicular prisms, having a deep ruby or garnet-red 

 colour, with a bluish- violet or light purplish reflexion-tint ; it is 

 sometimes deposited in thin flat plates, or long, flat, acicular prisms ; 

 these, when thin, transmit a pure yellow colour, but in thicker 

 plates it becomes reddish, with a tinge of brown. 



There is scarcely any appearance of double absorption in this 

 salt ; the thicker crystals alone exhibit it, when their usual tint be- 

 comes darkened on analysis with a Nicol. 



This salt requires 31 parts of boiling spirit, and 121 parts at 62° 

 to dissolve 1 ; water precipitates it as a cinnamon-brown powder. 



Its deep marone-coloured large aciculae had a specific gravity of 

 1-7647 at 62°. 



These large crystals, exposed whole to a temperature of 212°, de- 

 crepitate afterwards on exposure to the air, but dried at 212°, they do 

 not appear to lose further water after prolonged exposure to the 

 drying bath. 



The author having supplied Dr. Sheridan Muspratt with a 

 quantity of this salt, has been most obligingly furnished with the 

 results of his examination ; from which it will be seen that those 

 pre\iously obtained by the author have been confirmed. 



Herapath. Muspratt. 



637 100-000 100-000 



