Prof. Chapman on the Classification of Minerals, 17 o 



nine) cannot produce them, therefore we perceive that quinine 

 passes out of the system without experiencing any elementary 

 change. 



One subject is worthy of remark: the patient was taking 

 40 grains of the disulphate of quinine (and quinidine) ; there 

 were found 1*4 grain of mixed alkaloids, which would be equiva- 

 lent to 1*884 grain of the disulphate of commerce ; and if the 

 patient voided 3 pints of urine in twenty-four hours, we should 

 only account for 11*304 grains of the remedy used, leaving a 

 deficiency of 30 grains ; three-fourths of the substance being yet 

 unaccounted for, which has either been assimilated in the body, 

 or has been destroyed in its transit through the vascular system. 

 It would be interesting to undertake a series of quantitative 

 analyses in the healthy subject to determine these points : — 



1st. Whether the whole of the quinine ingested disappears by 

 the kidnies. 



2ndly. If not, whether it passes out by other excretory organs, 

 and which. 



3rdly. To discover at what period after ingestion all evidence 

 of its elimination from the kidnies ceases. 



These questions having been answered, in health, they must 

 be repeated when quinine has been used remedially, and by so 

 doing we shall perhaps be in a position to say what the medical 

 equivalent of quinine may be in a given disease. 



32 Old Market Street, Bristol, 

 July 10, 1853. 



XXIV. On the Classification of Minerals. By E. J. Chapman, 

 Professor of Mineralogy and Geology in University College, 

 Toronto, Canada West ; late Professor of Mineralogy in Uni- 

 versity College, London*. 



A CLASSIFICATION of natural objects should evidently 

 fulfil the two following conditions : it should enable us to 

 make out readily the name of any one of the included bodies, 

 and to group these in accordance with their natural attributes 

 and affinities. It should be thus, at the same time, a classifica- 

 tion for the discrimination, one from another, of the objects in 

 question, and a classification for the study of their analogies. 

 So far as regards Mineralogy — speaking always as to the present 

 state of our knowledge — these two conditions do not seem to be 

 attainable in a single classification. In Zoology and Botany, the 

 great leading divisions of Cuvier, on the one hand, and those of 

 De Jussieu and DeCandolle on the other, bearing, as they do, 

 the undeniable impress of truthful interpretation, are universally 

 adopted ; although, from time to time, a few subordinate modi- 

 * Communicated by the Author. 



