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to occupy nearly one-half of its area. Bymeans of a wooden beater the alhes are ram-med down very clofe, efpecially between thebars of the frame, as it lies on a flat floor, morealhes are then added and beaten carefully in tillthe frame is quite full. A cavity is then formedin the teft by a fharp fpade, for the purpofe ofcontaining the melted metal, and at one end ofthe frame a femi-elliptical hole is cut quitethrough the alhes to form a paflage for thelitharge, in forming which, care mull be takento leave a brealt of fufficient folidity and thick-nefs between this hole and the cavity; two{hallow channels are then made acrofs the breaftthrough which the litharge may flow downthe hole, and fo efcape out of the furnace.The tut being thus prepared is placed in thefurnace, fo as to occupy and cover the largeoval hole in its bottom, and is fixed firmlyin its place with tempered clay. A gentle fireis now to be lighted and gradually increafedtill the tell is red hot and ceafes to emit fleamfrom its under fide : an aperture in the furnacecalled the feeding hole, is then opened, and thetell is charged with melted lead, the fire israifed, the blaft from a pair of double bellowsis let on, and the cupellatlon commences. Oneof the channels through the breaft of the cupelis deepened from time to time, to allow a freepaflage for the litharge; and frelh charges ofmelted lead are poured into the cupel, till thegutter is fo worn as not to allow the cupel tocontain more than an inch in depth of metal.The blaft is then taken off, the old gutter com-pleatly filled up with moiltened alhes, and thebafon of the cupel replenilLed with meltedlead: the blaft being again turned on, the li-tharge is directed into the channel at the otherend of the breaft, and the operation goes on asat firft, till this gutter is likewife worn down,and the teft contains no more than about 60 lbs.of metal which is let out into an iron pot, andthus this firft part of the procefs is compleated.The fecond cupellation is fimilar to the former,and not materially different from the French mode except that when the filver is compleatlyrefined, it is allowed to cool gradually, infteadof having water poured upon it, and the confe-quence is, that while congealing, a portion offilver fpirts out, and is probably loft.

2. As an example of the method of treatingthe proper ores of filver, we {hall give an ab-ftradft of the proceffes employed at Aliemont inFrance , under the diredlion of M Schreiber. 0The ores where rough are chiefly native filver,and the fulphuret of filver, mixed with a little

arfenical cobalt, with pyrites, with iron ochre,with clay, calcareous fpar, and other earthyminerals. Much of the filver is in extremelyminute grains difperfed through the gangue foas to render it impolfible to feparate the llonyparts by walhing. The ore therefore after be-ing picked by hand is pounded dry in a {tamp-ing mill and is thus reduced to the confidenceof a coarfe fand; in this date it is aflayed, andcontains on an average about TTTf of its weightof filver. As it holds no fuperfluous quantityof fulphur there is no neceffity for roafting itprevious to fufion. On account of the refrac-torinefs of the ore, it is expedient to make ufeof quicklime, fcoriae from a preceding fufion,and flag from the iron forges by way of flux ;and in order to furnifh the proper quantity oflead of which the ore is naturally'entirely def-titute, it is mingled with pulverized galena,with the litharge and fcorite furnifhed by therefinery, and with old cupels ground to pow-der, in fuch proportions that, the lead obtainedby the fufion {hall contain 2 per cent, of filver,allowing at lead 20 per cent, of the lead to beloft by evaporation or combining with the fco-rise. The above materials being properly mixedtogether are put into a powerful blaft furnace,with alternate charges of charcoal, and the pro-duces of the fufion are lead holding filver, ablack compact fulphureous femi-metallic fub-ftance called Matt, and fcorise. The fcoriaeundergo no further treatment, except that acertain portion is referved as a flux for the nextparcel of ore; the matt being tolerably rich infilver is remelted with litharge, and the leadobtained carries with it nearly the whole of thefilver, fo that it is not worth while to fufeagain this fecond matt, although it dill containsa portion of precious metal. The lead pro-cured by thefe operations when refined yieldsabout 2 per cent, of filver; the cupellation isperformed at a higher heat than ulual, whichperhaps is rendered neceffary by the prefenceof a little iron, the confequence of which is,that the lofs of metal by evaporation, inftead ofbeing about 7 or 8 per cent, amounts at leadto 20 per cent, and as every pound avoirdupoisof the lead thus volatilized contains from 6 to10 grs. of filver, the lofs in this procefs isprodigious, and might in all probability begreatly diminilhed by the mixture of a muchlarger proportion of lead with the filver ore.

3. Other filver ores befides this metal afford ,both lead and copper; and as the treatment inthis cafe is the mod complicated, we ft12.ll givea (hort {ketch of it. The procefs begins by

• Journ. des Mines, No.59,4>. I.