112 THE CANADIAN NATURALIST. [Dec. 



but little reference either to physical or chemical characters, and 

 in the present state of our knowledge is valueless, except as an 

 effort in the right direction, and an attempt to give to mineralogy 

 a natural system. With similar views as to the scope of the 

 science, and with far higher and juster conceptions of its method, 

 Stallo, in his Philosophy of Nature, has touched the questions 

 before us, and has attempted to show the significance of the 

 relations of the metals to cohesion, gravity, light, and electricity, 

 but has gone no farther. 



In approaching this great problem of classification, we have 

 to examine — first, the physical condition and relations of each 

 species, considered with relation to gravity, cohesion, light, elec- 

 tricity, and magnetism ; secondly, the chemical history of the 

 species ; in which are to be considered its nature, as elemental or 

 compound, its chemical relations to other species, and these 

 relations as modified by physical conditions and forces. The 

 quantitative relation of one mineral (chemical) species to another, 

 is its equivalent weight, and the chemical species, until it attains 

 to individuality in the crystal, is essentially quantitative. 



It is from all the above data, which would include the whole 

 physical and chemical history of inorganic bodies, that a natural 

 system of mineralogical classification is to be built up. Their 

 application may be illustrated by a few points drawn from the 

 history of certain natural families. 



The variable relations to space of the empirical equivalents of 

 non-gaseous species, or, in other words, the varying equivalent 

 volume (obtained by dividing their empirical equivalent weights 

 by the specific gravity), shows that there exist, in different species, 

 very unlike degrees of condensation. At the same time, we are 

 led to the conclusion that the molecular constitution of gems, spars 

 and ores, is such that those bodies must be represented by 

 formulas not less complex, and with equivalent weights far more 

 elevated than those usually assigned to the polycyanids, the 

 alkaloids, and the proximate principles of plants. To similar 

 conclusions, conduce also the researches on the specific heat of 

 compounds. 



There probably exists between the true equivalent weights of 

 non-gaseous species and their densities, a relation as simple as 

 that between the equivalent weights of gaseous species and their 

 specific gravities. The gas, or vapor of a volatile body, consti- 

 tutes a species distinct from the same body in its liquid or solid 



