MET 



61 



MET 



Mot.. 



Mrullur 

 (7- 



Iroo. 



a force oa the eppoaite aide of the Strait*. The inha- 

 bitants, nevertheless, are accused of having engaged 

 with the other iaUnden, to betray 



laraay, 



*4 many of the 

 of a military r nmmiminii. composed partly of British, 

 and partly of Sicilian officers. Beat Long. 15" iff. 

 North Lat. 38 \tf, 



ftlESTA. See SPAIN. 



ME in iumoat iilamlail signification, 



awaaa* the working of metal* in every lifcant way. It 

 therefore include* ending, parting, anieiting, aaeaying, 

 Ac. in it* nor* limited sense however, it ia used lo 

 the proceaa of (melting, or the separation of 



r of these, with the view of 

 value. Ia this laet sesue it is 

 A Immt all the ore* employed ii 



letter, from which they must be 

 they are subjected to 

 The method* fctloved hi the 

 mth." 



Theaaaayof 



with the 

 all thedi 



either of 



two caflerent ways, 

 ig the quaotitiea of 



the -re 



only the proowtsoa of the aaotal (or which k ia wMwkw*. 

 The letter of theaa ia Mad in the art., and ia more 



the 





Wlen 



Bielal m the different piece*. 

 th* ore mutt o r*dne*d to o 



In 



mutt o r*dne*d to powder, or to anall 

 iti* waiaHMd.aodor.aaMt betake* that 



it << throw, out of thaTMel during the operation, and 

 bould not be removed from the crucible 



till it ia 



If the 



be well performed. 

 have a cwmem eur. 

 the acoria will be 



cold. 



the metallic button 

 bee. end will b. of uniform 



cea* several limes, and, a* in general, there will Lea 

 alight Jiffusaa ia the reaeka, we must take the mean 

 of the whose, ea the Quantity of metal ia the ore. 



In the faUowiaf*>4DVrw.waach metal, will be in. 

 ciwded the diflerrnt methods practia*d hi 1^* meatinar 

 lamwJmVmal*.* 

 with the view of ..rntsmin, the qaaatity of mtaJ in 



ace IKOK. 



differ* a little, accord- 



which they are 

 ai the art* are 



/roe. 



For the reduction of iron 



Attay. The aaaay of iron 

 ingto the ore employed. 



The common magnetic iron-stone i* aaaayed by mix- 

 mg k, when reduced to powder, with about twice its 

 weight efa flax, mapoeedof 1 of charcoal, 6 of chalk, 

 and! of bottlegjaa*. The mixture muat be exposed to a 

 very strong heat in a blaat furnace, for about an hour, 

 after which the iron will be found at the bottom of the 

 crucible. If the ore contain sulphur, it must be roast- 

 ed previous to Ha mixture with the flux. 



The other ore* of iron are assayed nearly in the same 

 way. V> hen very liuJe earthy matter i* present, they 

 may be reduced by using charcoal without the flux ; and 



if the ore contain much calcareous matter, the quantity M* 

 of clialk in the dux may be diminished. * 



Id. ^ 



Gold i always found in iu native state, generally al- Gold. 

 loyed with ailver and copper, and occasionally with tel- 

 lurium. Some of the iron pyrites, and galena also, con. 

 tain a sufficient quantity of this metal, to make them va- 

 luable as on* of gold. 



When gold ia found alloyed with silver mixed only 

 with stoney matter, the method of extracting the metal 

 ia very simple. In working a mine containing gold 

 in thia tatr, the whole of the matter procured from the 

 vein, U collected and broken into pieces, about the aise 

 of a nut, which are arranged into heaps, according 

 to their ricbneaa. The email fragment*, and the re- 

 fute of the different processes, are also collected and 

 arranged according to their value. The quantities thus 

 procured/ are afterward* broken into smaller piece*, 

 and freed as much as possible from impurities. They 

 are then reduced to powder, and made into a thick 

 paste with salt and water. Mercury ia now squeexed 

 through a leather bag on the mixture, and as the metal 

 flows in, in very minute globule*, it ia intimately blend- 

 ed with it by mean* of wooden apatulea. \\hrn the 

 requisite Quantity of mercury ia added, the whole ia 

 beat together, and kept at about the temperature of 

 boiling water, for two or three days, by which the 

 union of the gold and mercury ia promoted. The 

 earthy matter ia then carried off by levigation, and the 

 aapailauais mercury moored, by squeezing the aroal- 

 fam through a leather bag. What remains is subjected 

 to diauUattoo. by which the mercury i* driven off, and 

 the gold i* obtained, perhaps containing a little silver. 



The method of separating theae will be explained when 



trt-i'.i.K' . : ......r. 



When the other ore* containing gold are found in 

 the same mine, they are carefully separated from the 

 former, and are collected into heaps, arranged at . 

 ing to their richnea* and hardneas. The proceaa for ex- 

 trading the gold from these, i* much more complicat- 

 ed than that just described. 



In extracting gold from these ores, the first part of 

 the proceaa, consist* in separating the metallic from the 

 earthy substance*. For thia purpose the ore U reduced 

 to powder, in a tlamfiu^-mtU. The stamping-mill con- 

 aista of a large cittern, in which the ore is placed, and 

 through wtuch a stream of water passes, and of the 

 stampers, which are heavy beams of wood, terminated 

 below, by iron, and which are moved upwards and 

 downward* by a water-wheel. 



Great attention ia 



, in thia part of the pro- 

 ccea, that the whole of the foreign matter which can 

 be removed by the hand, be atparated before the ore i* 

 pot into the cutern, and that the proper force be ap- 

 plied, according to the hardness of the ore. 1 Jus is 

 easily regulated, by increaaing or dirr.inuhing the dej-.th 

 of the layer of ore hi the cittern ; hence the quantity 

 of ore nut in, is always inversely ai its hardness ; ac- 

 cordingly when the layer of ore ia thin, the stamper* 

 have a greater fall, and the ore ia thus sul>jecu<l to 

 greater force. It i* necessary also, that the ore be 

 placed in a particular way. The layer i* so formed, 

 that below the two outer stampers it i* thickest, and 

 gradually diminishes towards the centre. When the 

 ore i* reduced to powder, and sufficiently fine to float 

 in the water, it ii carried off, by the stream of this fluid 

 into vessel*, in which it is deposited ; the heaviest be- 

 ing deposited nearest the cistern. Particular care is 



