Section III, 1888. [ 61 ] Tbans. Roy. Soc. Canada. 



ABSTRACTS, 1S88. 



1. — Tlic Glassificdiloii and Nomenclufnre nf Mttallhie Minernh} 



By T. Stekry Hunt, LL.D., F.R.S. 



(Presented May 30, 1888.) 



The author recalls his essay ou " A Natural System iu Miueralogy," presented in 1885, 

 aud ]iublished iu Volume III of the Transactions of the Royal Society of Canada, whereiu 

 he discussed the grounds and priiuùples of a true natural system of classification, and 

 exemplified them by au extended study of the order of Silicates. It was then proposed to 

 divide the mineral kingdom, for natural-historical purposes, into four classes, including 

 respectively the Metalline, the Oxydized, the Haloid and the Pyricaustate or combust il)l(' 

 species. Of these the first, third and fourth classes iuclude only one order each ; the 

 second embracing seventeen orders. Adopting a Latin terminology, the first class becomes 

 the Metallace^, including the order of the Metallata, which is divided into two 

 sul)orders, the MelaUometaUinea and the SpalometaUinea ; based on the fundamental difter- 

 euce recognized by all naturalists between the group of the Glances and that of the 

 Blendes. The author then proceeds to show the reason for including iu the same order 

 with these the group of the Pyrites, and that of the native Metals, aud arranges all these 

 in nine tribes, based alike on chemical aud ou physical grounds.^ 



Preparatory to this, however, the relations between hardness aud specific gravity on 

 the one hand, aud chemical equivah'ut on the other, are next discussed ; it beiug main- 

 tained that these physical characters vary with the condensation of the species, or, in other 

 words, are functions of the integral or so-called molecular weight ; which is at the same 

 time the density of the species, that of hydrogen beiug unity. The weight of a given 

 volume of this being known, that of the same volume of any other species, whether 

 gaseous, liquid or solid, is truly its equivalent weight. It is then shown that hydrogen 

 gas at standard temperatirre aud ijressure being H., = 2, water vapor, H._,0, = IV'96 ; and 

 liquid water 1192 ( HoO ) = 21408, or in round numbers 21400, which being that of a 

 body whose specific gravity is assumed as unity, — we are able to calculate the integral or 

 equivalent weight of all species compared with it. It follows that the integral weights 

 of solid aud liquid species are very elevated, and that these are highly condeused or 

 polymeric bodies, whose coefficient of condensation is determiued by comparing their 



' A more extended analysis of this paper appears under the same title in the Proceedings of the American 

 Pliilosophical Society for 1888, and is reprinted in the Chemical News for August 10 and 17, «idle an unrevised 

 rejîrint of the present abstract will be found in an earlier number of the latter publication. 



-See also Supplement to a Natural System of Mineralogy, presented in 1886, and published in these Trans- 

 actions, vol. iv. 



