GEOLOGY AND MINERALOGY. 303 
ponding eavelope shall be opened, and the name of the author communicated to 
the Institute. The other envelopes shall be destroyed without being opened. 
5. Should the Judges think proper, they may requre the experiments described 
in any of the memoirs to be repeated in their presence. 
6. The memoir which may obtain the Premium, shall become the property of 
the Franklin Institute and shall be published as it may direct. Any unsuccessful 
memoir will be returned to the author at his request. 
GEOLOGY AND MINERALOGY. 
ANALYSIS OF CANADIAN WOLFRAM.—BY 1. STERRY HUNT, F.B.S. 
In volume 1, page 308, (New Series), of the Canadian Journal, will be found 
a erystallographie and mineralogical description, by Professor Chapman, of a 
specimen of Wolfram, discovered in a boulder of gneiss on the shore of “ Chief’s 
Island,” Lake Couchiching, Canada West. A chemical examination of a portion 
of this specimen has yielded the following results :— 
The specific gravity of the mineral was found to be 6°938. Two grammes of it 
were finely levigated, and decomposed by prolonged digestion with agua regia ; 
after which, the solution was evaporated to dryness, and the residue being heated 
with water and hydrochloric acid, the insoluble yellow portion was separated, 
washed with spirit of wine, and finally digested with ammonia. The ammoniacal 
solution left by evaporation and ignition, 1-469 grm. of tungstic acid. The 
residue, insoluble in ammonia, weighed 048 grm. It was*heated in a platinum 
erucible with fluorid of potassium, and an excess of sulphuric acid to drive off any 
silica which might be present, and then fused with the resulting bisulphate of 
potash. The fused mass was transparent, but on adding water white flakes sepa- 
rated, ="039 grm., and the solution contained :005 of oxide of iron and manganese. 
The loss, equal to -004 grm., was supposed to be silica, and the white matter, 
which was grey after ignition, and insoluble in a solution of potash, was regarded 
as niobic acid. 
The iron was separated as peroxyd from the hydrochloric solution by carbonate 
of baryta, and equalled 181 of protoxyd. The manganese, being lost by an 
accident, was calculated from the difference. We have thus, for 100 parts of this 
specimen of Wolfram, the following composition :— 
Prstietraeider site, ARs | Sieve WET ie. Mar 73°45 
INTODICHELED (pret wie Peete, SCCM I NPE 1:95 
Brovoxydron meron crt vee tere ie tele Lt Reta 9°05 
Protoxyd (ol maneancse sas ee eee e eeteiee 15°35 
ATC LT ree oe eee oat eee Sa PE 20 
100-00 
[These results lead to the general formula 2 (Fe0,W0°) + 3 (Mn0, W0?); the 
specimen belonging to the mangano-wolframit of Breithaupt, as stated in the 
mineralogical description referred to above.] 
