On the Preparation of Quina and Cinchonia. 171 



clei at B and C in fig. 1, with those of the lymph and chyle 

 globules, which I have depicted in Gerber's Anatomy. 



Structure of Fibrine. 



In the section on this subject in the last Number of the Phi- 

 losophical Magazine, p. 109-111, it should have been stated 

 that in many fibrinous exudations or false membranes, result- 

 ing from inflammation, the structure is the same as that of 

 fibrine, coagulated either after removal from the body or 

 within the circulating channels simply from death. In false 

 membranes the fibrils are often very distinct : they form a de- 

 licate net-work, which incloses exudation corpuscles, much 

 resembling the organic germs before described in pale clots of 

 fibrine formed without inflammatory action. As these fibrils 

 in both instances appear to be formed in the act of coagula- 

 tion, it would require some modification of or departure from 

 the theory of M. Schwann to explain their origin. 



Tubercle. 

 It has long been a question whether tubercular matter in 

 the lungs be situated in the cellular (filamentous) tissue out- 

 side the air-cells, or at the surface of the mucous membrane 

 within these cells. It may be merely mentioned that I have 

 clearly detected tubercular deposit in the latter situation ; and 

 that Dr. Willis, in his forthcoming English version of Prof. 

 Wagner's Physiology, will give an engraving of tubercular 

 matter within the air-cells. This of course will not decide 

 what is always the case in tubercular consumption ; but it seems 

 to be a fact of interest in regard to the precise seat of tubercle 

 of the lungs. 



XXVIII. On the Preparation of Quina and Cinchonia. 



By M. F. C. Calvert, Preparateur du Cours de Chimie 



appliquee au Jardin des Plantes a Paris. 



To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen, 

 \ LLOW me, through the medium of your widely-circulated 

 ■**• Journal, to make public a new chemical fact discovered 

 by me relating to the extraction of quina and cinchonia from 

 cinchona bark, by the knowledge of which, I believe, the pro- 

 cess usually followed by the manufacturers of these alkaloids 

 may be considerably improved. 



In order to obviate some of the difficulties which have hi- 

 therto been experienced in extracting the alkaline bases of 

 cinchonia, it appeared to me desirable to discover a process 

 by which, from a certain quantity of cinchona bark, all the 

 quina and cinchonia contained in it might be extracted. In 



