SCIENTIFIC SUMMAKT. 
217 
pervading reducing agency^ doubtless that of carbon of dead organisms — 
'whicb had lived probably to some extent even in the concentrated brines of 
the ocean^ but chiefly in cooler and more dilute waters along and near its 
coasts, formed by the influx of continual torrents proceeding from a constant, 
universal, and enormous condensation upon the mountain heights and 
slopes — the metallic sulphates become sulphides, and were as such deposited 
in admixtiu’e with the sediments and precipitates (whether mechanical or 
crystalline, or both) of the oceanic waters. Fifth. The carbon doing this 
work passed back in the act into the atmosphere as carbonic acid, to be 
again taken up by vegetable organisms ; — or, by condensing as aqueous so- 
lution on the mountain slopes, to be converted into calcic bicarbonate by 
contact with calciferous silicates, and flow back in this form to the ocean, to 
be there itself converted sooner or later into sediments, by both chemical 
and 'vital influences ; thus the carbon performing alternately its several 
allotted functions, till finally locked up in the forms of calcite, dolomite, 
chalybite, graphites, coal, petroleum, asphalts, and other resinoid substances. 
Reeve's Patent Gun-Felt. — This compound, which has been patented by Mr. 
F. W. Iteeves, is intended to be used as a substitute for gunpowder, for mili- 
tary, sporting, and mining purposes. Its physical and mechanical properties 
are intermediate between those of gunpowder and gun-cotton. This substance 
is derived from cotton rags which, after being torn to fibres, are rendered 
somewhat explosive after the manner of gun-cotton, are subsequently made 
more explosive by the addition of other ingredients, and thus a uniformity is 
obtained which, according to the inventor, cannot be relied on with pm’e 
explosive fibre such as gun-cotton. It is used in a pure state, and by bulk 
is as explosive as gunpowder, and a charge generates a greater volume of 
gas a charge of gun-felt weighing I dram being fired in a shot-gun with 
No. 6 shot, will at a range of 40 yards penetrate 28 sheets of brown paper, 
to cause this effect it requires at least 3 drams of the best gunpowder, and as 
at the moment of ignition the reaction is not so sudden as with gunpowder, 
most of its explosive force being applied when the projectile has overcome 
the greater part of its inertia, the recoil of the gun is not so great, being 
about 50 lbs. with gun-felt to 67 lbs. with gunpowder. This material is 
said to be used in rifles with good effect, and to be cheaper, cleaner, and 
safer in use, and, finally, is productive of little recoil or smoke. 
Two New Minerals. — Herr Hagemann has discovered two minerals ac- 
companying cryolite, and has termed them dimetric imclinolite and Arksutite. 
The first resembles the pachnolite described by M. Emossj it occurs in 
prisms or in quadrangular pyramids, cleaveable in the direction of the base, 
of a pinkish white colour and very brilliant. Its density is from 2-74 to 
2'76, and its hardness the same as cryolite. Sulphuric acid easily attacks it. 
The specimen analysed contained 2 per cent, of silica, which M. Hagemann 
considers foreign to the composition of the mineral, to which he assigns the 
formula, Al2Fl3-b2(fCa-l-|-Na)Fl-f-2HO. Arksutite is granular, white, and 
crystalline, and, like the other mineral, very brilliant. Its density is from 
3-03 to 3*17 ; its hardness is equal to cryolite. At a dull red heat it fuses, 
without loss of water. Analysis gave numbers corresponding to the formula 
2 (Ca,Na)-|-Fl-j-Al 2 Fl 3 . These two minerals occur at Ai’ksut-Fiord, in 
