young’s TRAVELS IN FRANCE.
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The procefs purfued in this manufactory would be tedious to ninety-nine hundredthsof my readers, I {hall therefore only give a few heads from the memoranda I made afterhaving viewed it attentively : the reputation of the Due de la Rochefoucauld, as an ablechymift, united with his rank, induced the director of the fabric to explain the matterfully ; 1 attended him in viewing the work: they firfl pound the ore into powder, whichis placed in a fort of fpoon in a furnace to roaft, for the purpofe of expelling the arfenicby fublimation ; it is received in a canal or chimney, which winds horizontally ; by anopening in the wall a man enters for gathering this arfenic ; this is an operation verydangerous to the health, yet for 4 f to 3 liv. a day they get men to execute it, who fora preventative of the ill effiedts fwallow fome milk, and keep cloths to their mouths andnofes dipped in milk, and kept conftantly wetted. r l he cobalt remains after this roaftingin a greyifh black calx ; bifinuth is found mixed with it, which is found at the bottomof the fpoon. They have another way all'o, which is that of fufing the cobalt, thus purg-ed of its arfenic, in order to get the regulus ; I faw fome large pieces of regulus withbifmuth adhering, which were in all probability procured in this method; hitherto theyhave not applied the bifmuth to ufe, nor tried whether it would anfwer to fend it tothofe places where it is worked.
Having thus obtained the calx of the cobalt, they mix it with pot-afh and roafied flintsas a flux, in large crucibles, which are placed fix together, in a large long furnace, theupper part of which is arched to an angle, a current of air pafling ; the furnace is heatedwith drybeechwood billets. Some chymiftsalfert,that there fhould be of flintsthree to oneof the cobalt, but they ufe fixteen to one, which they fay is the Saxon method, and thefeflints contain fome fmall portion of cobalt; it requires a fierce fire of twelve hours toreduce the calx of cobalt to a glafs ; when this is nearly jn a white fufion (as they termit) they take it out w'ith iron ladles, and throw it into a veffel conflantly fupplied withfrelh water for cooling, from which it is taken to a pounding mill and beat to powder,in which operation they almoft always find fome drops of regulus, which are taken out ;when pounded it is carried to a kind of table three flories high, ftreams of water areturned on to it, while two men at each table Air it ; this is for freeing the cobalt fromimpurities ; it pafles with the water into a large tub pierced at different heights, that thewater may flow away and leave the cobalt at the bottom ; but as this water is in fomemeafure tinctured with this precious material, it is not fuffered to run to u'afle ; a largecifiern is under the whole room into which it is received, and whence it is drawn off fromtime to time; the cobalt thus gained is of the worft quality.
The wafhed cobalt is carried to a mill, which grinds it under a flone, the powder isreceived in a large vefiel of water, which is made by trituration to imbibe the tin&ure ,and is hence drawn off four times into as many veffels, that the water may depofit thema erial. The powder thus gained is carried to the drying room, where it is dried inlong fhallow trays, and then reduced to a finer powder by fifting ; in which ftate it is fofine that they water it with a gardener’s rofe to prevent its being blown au'ay, in whichftate it is in order to pack into calks for fale.
The motion to the whole machinery is given by two underfhot water wheels.
Vicinity to the Spanifh mine, and cheapnefs of wood were the inducements to eftabllflithis fabric here; they now make pot-afh, v/hich was formerly imported from the Baltic,and coft 40 liv. the quintal, but they can make it here for 12 liv.
Narbonne.—A manufadure royale of filk fluffs, the mafler of which is a bankrupt.This is the fecond of thefe privileged eftablifhments which 1 have found in the fame fitu-ation j Chateauroux the former. It fhould feem that government never interferes byprivileges but to do mifehief.
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