232 Scientific Intelligence. 



tion by logarithms and arcs of circles. The sections on logarithms 

 are very valuable, and will follow well after the perusal of the in- 

 troduction to the subject by Biot which we have given at the com- 

 mencement of the present number. We confidently recommend this 

 admirable treatise to the attention of mathematical teachers, who 

 cannot fail to obtain from it, assistance of the most valuable descrip- 

 tion, in smoothing the way for the reception of the calculus by young 

 minds. 



Article IX. 



SCIENTIFIC INTELLIGENCE. 



I. — On the Arrangement of Mineral Collections. 



The notice, in your Number for January, of a new system of 

 Mineralogy, &c. by Professor Thomson, will excite the attention of 

 your readers : and I wish to profit by the occasion, to examine the 

 relative advantages of the chemical and natural arrangement of 

 mineral collections. My own experience, such as it is, has led to the 

 preference of the latter mode ; and the object of this paper will be, 

 to give, in very general terms, the reasons for that preference : 

 reserving details for a more advanced stage of the discussion, into 

 which I wish to draw either Professor Thomson, or one of his 

 qualified pupils who may have more time to spare. 



In the case of private collections, there may be different motives 

 for preferring the one or the other ; or, what is rather more common, 

 something between the two. The miner would prefer the analytical 

 order ; the lapidary the natural ; the virtuoso would spare himself 

 the labour of a strict arrangement, by adopting the intermediate or 

 compound; and the naturalist, perhaps, a divided system; arranging 

 chemically those species which depend, for their scientific or practical 

 interest, on their elementary ingredients ; and according to their phy- 

 sical properties, those which owe their interest chiefly or altogether 

 to those properties. For mineralogy, though so intimately connected 

 with chemistry, is certainly a main branch of natural history. 



But, whatever may be the inducement to the particular mode of 

 arrangement of a private collection, of public ones it may be assumed, 

 that their chief purpose is to facilitate the knowledge of mineralogy ; 

 and on this ground it is that the chemical system seems to me 

 objectionable. 



I. From the inaptitude of its grouping to produce impressions of 

 general similitude aud distinction ; descending through divisions and 

 subdivisions, and thus facilitating the discrimination of individual 

 species. 



II. From the uncertainty of analysis, in the present state of science, 

 as a distinction between mineral species. 



III. From its fixing our attention upon analytical distinctions, 

 and thus diverting it from those upon which we must depend, for 

 distinguishing one mineral from another. 



It may be proper to exemplify the application of these objections. 



