M I N 



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M I N 



similarly blended, in every part, as to 

 exhibit a uniformity of appearance. 



Compound minerals more or less evi- 

 dently discover to the eye, that they are 

 composed of two or more simple mine- 

 rals, which either merely adhere to each 

 other, or, as is sometimes the case, appear 

 imbedded one in the other. Compound mi- 

 nerals are frequently aggregates or rocks. 



The description of minerals, and their 

 arrangement in systematic order, must 

 result from an investigation of their pro- 

 perties. These properties consist in cer- 

 tain relations which minerals bear to our 

 senses, or to other objects. Some of 

 them are discoverable by mere inspection, 

 or, at most, require some simple experi- 

 ment to be made upon the mineral to as- 

 certain its hardness, structure, gravity, 

 &c. while others cannot be observed 

 without a decomposition of the mineral. 

 All these properties are usually called 

 characters. We hence have a twofold 

 division of the properties or characters of 

 minerals into chemical and physical. 

 Cleaveland. 



MI'NERALOGY. That science, says Cleave- 

 land, which has for its object a knowledge 

 of the properties and relations of mine- 

 rals, and enables us to distinguish, ar- 

 range, and describe them. 



Jameson defines mineralogy to be that 

 part of natural history which makes us ac- 

 quainted with all the properties and rela- 

 tions of minerals. It is divided, accord- 

 ing to that professor, into two grand 

 branches, namely, mineralogy properly so 

 called, and geology. Mineralogy treats 

 of the properties and relations of simple 

 minerals / while geology considers the 

 various properties and relations of the 

 atmosphere, the waters of the globe, the 

 mountain rocks, or those mineral masses 

 of which the earth is principally com- 

 posed, and the form, density, heat, elec- 

 tricity, and magnetism of the earth. 



The history of the materials of the 

 crust of the globe, their properties as 

 objects of philosophical enquiry, and their 

 application to the useful arts and the 

 embellishments of life, with the charac- 

 ters by which they can be certainly dis- 

 tinguished one from another, form the 

 object of mineralogy, taken in its most 

 extended sense. 



There is no branch of science which 

 presents so many points of contact with 

 other departments of physical research, 

 and serves as a connecting link between 

 so many distant points of philosophical 

 speculation as this. Nor, with the ex- 

 ception of chemistry, is there any which 

 has undergone more revolutions, or been 

 exhibited in a greater variety of forms. 

 To the ancients it could scarcely be said 



to be known at all, and up to a com- 

 paratively recent period, nothing could 

 be more imperfect than its descriptions, 

 or more inartificial or unnatural than its 

 classification. It was only, however, 

 whSn chemical analysis had acquired a 

 certain degree of precision and universal 

 applicability, that the importance of mi- 

 neralogy as a science began to be recog- 

 nized, and the connection between a 

 stone and its ingredient constituents 

 brought into distinct notice. The ar- 

 rangement of simple minerals has always 

 been a subject of controversy with miner- 

 alogists ; and the discussions to which 

 it has given rise have materially contri.- 

 buted to the advancement of our know- 

 ledge of the natural and chemical history 

 of minerals. Berzelius contends for the 

 chemical arrangement, according to which 

 the species are grouped in conformity 

 with their chemical composition and 

 characters. Werner rejects the pure che- 

 mical, and adopts the mixed method, in 

 which the species are arranged and de- 

 termined according to the conjoined ex- 

 ternal and chemical characters. The 

 writers of the W T ernerian school usually 

 divide mineralogy into the five following 

 branches ; namely, oryctognosy, chemi- 

 cal mineralogy, geognosy, geographical 

 mineralogy, and economical mineralogy. 

 Of late years, the arrangement according 

 to external characters alone (named the 

 natural history system) has been advo- 

 cated by Mohs. Among the external 

 characters of a stone, none were, how- 

 ever, found to possess that eminent dis- 

 tinctness which the crystalline form 

 offers ; a character in the highest degree 

 geometrical, and affording the strongest 

 evidence of its necessary connection with 

 the intimate constitution of the sub- 

 stance. The full importance of this cha- 

 racter was, however, not felt until its 

 connection with the texture or cleavage 

 of a mineral was pointed out, and even 

 then it required numerous and striking 

 instances of the critical discernment of 

 Haiiy, and other eminent mineralogists 

 in predicting from the measurements of 

 the angles of crystals which had been 

 confounded together, that differences 

 would be found to exist in their chemical 

 composition, all which proved fully jus- 

 tified in their result before the essential 

 value of this character was acknowledged. 

 A simple and elegant invention of Dr. 

 Wollaston, the reflecting goniometer, gave 

 a fresh impulse to that view of miner- 

 alogy which makes the crystalline form 

 the essential or leading character, by 

 putting it in the power of every one, by 

 the examination of even the smallest 

 portion of a broken crystal, to ascertain 



