1813.] upon Werner's Mlnp'alogical Method, 247 



crystallized specimen ; 1 mean chromate of iron and ceriie. 

 Nay, in his last publication, he allows that the knowledge of 

 the integrant molecule is not necessary to enable us to form and 

 describe species, and has thus brought back his own definitionj 

 so highly prized by Chenevix, to a state of identity with that of 

 Werner, which Chenevix has so unmercifully belaboured, as 

 utterly destitute of all pretensions to science or common sense. 



Thus with respect to the abstract definition of mineral species, 

 the superiority is unquestionably due to Werner. Many mineral 

 species have been established in exact conformity with this defi- 

 nition. Cinnabar, pyrites, tungslate of lime, sulphate of stron- 

 tian, may be mentioned as well-known examples. But I must 

 acknowledge that a rigid application of the definition of mineral 

 species is impossible; otherwise the number of species w^ould 

 become almost infinite, and a system of mineralogy of no use 

 whatever. The whole globe of the earth is composed of mine- 

 rals ; and the constituents of these minerals, as far as they have 

 been exami.isj^ consist of no less than 50 distinct substances 

 combined in^a great variety of ways. Minerals were early 

 divided into four classes, which possess characters sufficiently 

 distinct from each other; namely, stones, salts, comhustiljles, and 

 ores. In the salts, and a good many of the ores, the composition 

 is perfectly fixed, and the minerals belonging to them may be 

 arranged in strict conformity with the Wernerian definition. 

 The combustible minerals are few, and easily arranged ; though 

 the science of chemistry is not yet far enough advanced to allow 

 us to determine with precision respecting their composition. The 

 stones are composed of the nine earths, water, the fixed alkalies, 

 and about seven metals in the state of oxides; and these bodies 

 are found united ii\ an almost infinite number of proportions. 

 Were the definition to be strictly adhered to, almost every speci- 

 men of stone would constitute a distinct species; and there 

 would be as many species as mineral masses. Some means must 

 be devised to prevent this enormous multiplicity, otherwise 

 mineralogy would be of no service to mankind. The method 

 followed by the older mineralogists was to pitch upon some one 

 quality, which they considered as of primary importance : all 

 minerals agreeing in this quality they referred to the same 

 species; all disagreeing, to a different species. Haiiy has fol- 

 lowed the plan of the older mineralogists in this respect. He 

 has pitched upon the form of the integrant molecule, and has 

 laid it down as a rule that all minerals having the same integrant 

 molecule (provided the chemiqal composition agrees) belong to 

 the same species. 



The rule laid down by Werner is very different. He conceived 

 it necessary to include in his system all the minerals in nature, 

 though he believed at the same time that a great many of them 



