SECTION III, 1886. i 63] Trans. Roy. Soc. CANADA. 
VI.—Supplement to “A Natural System in Mineralogy, etc” 
By T. Sterry Hunt, M.A., LL.D. 
(Presented May 27, 1886.) 
§ 1. In the Transactions of this Society for 1885 appears a paper by the present writer 
entitled “A Natural System in Mineralogy, with a Classification of Native Silicates.” 
(Vol. III. Sec. iii. pp. 25-98.) In printing that paper, a considerable number of errors 
crept into the tables of the various tribes of silicates in the values of P and V, and some- 
times of D also, together with other errors in the formulas themselves. These tables, 
having been revised with care, are here reproduced, with the use of initial letters for the 
crystalline systems, and other changes, which permit them to be printed in a more compact 
form. In thus reprinting them, with the entire paper and some additions, in the author’s 
“ Mineral Physiology and Physiography ” (a volume now in the press), certain comments 
which originally appeared in the right-hand columns of these tables have been incorporated 
with the text. 
§ 2. In further extension of the principles of classification which we have adopted 
for the silicates, it should be said that bismuthic oxyd is to be reckoned with aluminic, 
chromic, ferric, manganic and zirconic oxyds; so that the bismuthic silicates, eulytite, 
agricolite and bismutoferrite belong to the sub-order of the Persilicates, and moreover, 
by their chemical characters, and their volumes, represent in that sub-order the spathoid 
type, of which no examples were known to the writer at the time of preparing the previous 
paper. They thus find a place in the tribe of the Perspathoids, as shown below in the 
revised synoptical table of the sub-order. Therein also the stannic silicate described by 
Breithaupt, in 1847, by the name of stannite may, perhaps, find a place among Perada- 
mantoids. Its specific gravity of 3.55, much below that of a corresponding mixture of 
cassiterite and quartz, leads to the conclusion that it is really a chemical compound. The 
name of stannite was subsequently, in 1868, applied by Dana to tin pyrites, the stannine 
of Beudant, but as its application by Breithaupt has priority, the sulphuretted tin pyrites 
may be called stannipyrite. 
Zirconic silicates are represented in the third sub-order of silicates by the adaman- 
toid species, zircon, lyncurite, auerbachite, and malacone, and in the second sub-order by 
catapleiite among zeolitoids, and by eudialyte, wohlerite and astrophyllite among spathoids 
and phylloids. It is, moreover, a question whether oérstedite may not be a zirconic 
adamantoid of this sub-order. 
§ 3. To recall the atomic notation here used to represent the quantivalent ratios in 
silicates, we subjoin the tabular view giving the symbols employed and their numerical 
values, hydrogen being unity (h = 1.00) :— 
