CLASSIFICATION OF MINERALS. 



When the first difficulties of the science have been overcome, and the 

 student has acquired a sufficient knowledge of minerals to be able to recog- 

 nise them by their characters and properties — the next step is that of 

 classification — or their arrangement into classes, families, and species. 



To accomplish this in a satisfactory manner is* a task of considerable diffi- 

 culty. Each author, in consequence, seems to consider himself at liberty to 

 recommend a system of his own — the result of which is that numerous modes 

 have been proposed by different writers, of various degree of merit ; some 

 natural, others artificial, and some, again, partaking of a sort of compromise 

 between these two extremes. 



This has led to much confusion, and a highly unsatisfactory state of 

 things. It is partly in consequence of the want of agreement between the 

 various authors who have treated on this branch of the subject, and the 

 practical inconvenience of a purely chemical arrangement (combined with 

 some other motives relating more especially to facility of reference), that 

 the author has been led to the adoption of an alphabetical form for the 

 present work. 



But although it has now become a recognised principle, that chemical 

 composition must constitute the basis of any really perfect system of classifi- 

 cation, an arrangement founded solely on chemistry is practically attended 

 with much inconvenience. In some instances, the adoption of an artificial 

 system, or some modification of one, may be found useful. For example, in 

 a collection of minerals intended to illustrate some special purpose, as the 

 application and use of minerals in the arts and in jewelry, what are com- 

 monly known by the name oi' gems and precious stones might with propriety 

 be allowed to occupy a prominent position, and be formed into a group by 

 themselves, as was proposed by Allan. On a similar principle, collectio'ns 

 illustrative of the mineral resources of our own and Foreign Countries (such 

 as those which will form a part of the proposed International Exhibition of 

 1862) will convey more information to the mind, and be of much more use 

 as objects of comparison, if each metal be made to form a separate group; 

 the ores of iron, of copper, and of lead, for instance, being all placed by 

 themselves. 



On the same principle, other modifications of previous systems may be 

 devised to suit particular cases, or as necessity may require. 



The system of classification proposed originally by Berzelius, and adopted 

 at the British Museum, is founded upon the Electro-Chemical theory. This, 

 in many cases, leads to a great amount of inconvenience in practice. The 

 minerals of the various metals, for instance, are by this means, dispersed and 

 widely separated from each other — occasioning much confusion to the stu- 



