6th, The cake, or combined regulus of gold and silver, obtained from the purification furnace, is separated into thin pieces in this manner : It is melted, and, in a state of fusion, cast into cold water. By this means it is obtained with a very extended superficies, and easily divided into a number of thin scales. These are put into immense glass retorts, of a spherical form, nearly filled with nitric acid. Here the silver dissolves, a gentle heat being communi cated to the retorts, to accelerate the solution. It has been usual to exclude foreigners from the great laboratory, where this takes place ; but as we had witnessed every operation, we were also permitted to view the interior of this chamber. The sight was beautiful. It was a spacious and lofty hall, filled with enormous globes of glass ranged in even rows, whence the nitrous gas was escaping in red fumes to the roof; the solution of silver being visible in all of them by the effervescence it caused ; the gold falling at the same time, in the form of a black powder, to the bottom of every retort. After the solution of the silver is completely effected, the acid containing the silver, by aug menting the heat, is made to pass into another retort, and the gold is left behind in the former vessel. Afterwards in creasing the heat to a great degree on the side of the sil ver, the whole of the acid is driven off, and the silver re mains beautifully crystallized within the retort. All the glass globes containing the crystallized silver are then cast into a common furnace, where the glass, by its levity, re maining on the surface of tho metal, is removed in the form of scorn. This is the last operation. The gold is smelted into ingots of 12,000 florins each." " In the essaying laboratory, instead of the long process we have described for extracting the precious metals from their ores, two simple and easy experiments are sufficient. The first is a trial of the pulverized ore by cupellation. About a tea-spoonful of the pulverized ore, first weighed, is put into a small cupel made of calcined bones : this be ing exposed to the heat of a powerful furnace, the lead, semimetals, &c. are either absorbed by the cupel, or they are sublimed. Nothing remains afterwards in the cupel but a small bead of combined gold and silver ; and by the proportion of its weight to the original weight of the ore, the value of the latter is determined. The gold is then separated front the silver by the solution or the latter in ni tric acid ; and the difference of the weight of the gold from the whole weight of the two metals, combined, determines the quantity of silver dissolved by the acid." " A hundred pounds weight of their richest ores contained from fonr to five marks of silver, and each mark of the silver about 15 deniers of gold." The mines are wrought pat tly at the expcnce of the crown, and partly at the cxpence of individuals, who pay a duty called urbur, and are besides obliged to deliver the metal at a fixed price to the royal treasury.
The number of miners employed by the crown at these mines amounts to 9,500, of whom 8000 are at Schemnitz ; and the expence to government of working is estimated at 50,000 florins a month, and the clear profits during the same period 12,000 florins, about 1333l, calculating- the pound sterling equal to nine florins. The workmen are paid, when the ore is rich, according to the quantity and quality of the ore raised, but when it is poor. they receive wages. The Schemnitz ores, in the space of thirty.three
years, (from 1740 to 1773) produced seventy millions of florins in gold and silver ; and those of Cremnitz thirty millions during the same period. The greatest produce, however, was derived from them in 1780, when they yield ed 2,429 marks of gold, and 92,267 marks of silver, mak ing 3,043,000 florins. In common years, according to the calculations of Born and Ferber, these mines, including the copper mine of Neusohl, where one quintal of copper produces twelve ounces of silver, yield from 58,000 to 59,000 marks of silver, and from 1,200 to 1,300 marks of gold.
The silver mines in Upper Hungary at Nagy-Banya, Felsoc•Banya, and Lapos-Banya, in the county of Szatl. mar ; at Metzenself, in the county of Bihar, with the cop per mines of Retz-Banya and Schmoelnitz, according to Mr Ferber, give an annual produce of from 12,000 to 15,000 marks of silver, and from 300 to 400 marks of gold. The copper and lead mines in the Bannat at Oravitza, Saszka, Dognaszka, and Moldava, yield annually about 111,04 marks of silver, and 203 marks of gold.
The copper mines of Hungary produce annually from 30,000 to 40,000 quintals. The richest are situated at Schnwelnitz in the county of Zips, and in the Bannat.
The lead mines in 1786 were wrought to the extent of from 14,000 to 15,000 quintals, but this produce is now con siderably diminished.
The iron mines in this country arc almost inexhaustible. The best is drawn from a mountian called Hradek, near Esetnek ; but as this metal is not subject to any duty or tithe, the annual produce of these mines have not been as certained. In the county of Goemor, including the dis trict of Kleinhont, there are eight great furnaces, a floating furnace, eighty-seven small ones, and forty-nine forges, which furnish annually 94,200 quintals of iron, worth 1,304,240 florins. But, notwithstanding the,great quantity of iron which this country produces and exports, they are, obliged to be indebted to Austria for most of their tools and vessels made of this metal.
Manganese is found near Felsoe-Banya, and in some of the iron mines ; titanium, in the county of Goemor near Roeze ; and tellurium, which was discovered by Dr Kie taibel in a mineral of Deutsch-Pilsen in the county of HoM. Mauy valuable and beautiful minerals are found in the Hun garian mines. Among them may be mentioned, amethysts invested by efflorescent manganese-spar, in a minute crys tallization upon the surface of the amethystine crystals; rich sulphurets of silver, called by the Germans iVeisgul den Erz, or white money ore," which is so malleable. that medals have been struck from the unwrought ore ; sulphurets of silver, both massive and crystallized ; red an timonial, or ruby silver crystallized : dodecahedral and pri mary crystallizations of ; phosphates and carbonates of lend crystallized ; red sulphurets of arsenic crystallized; diaphanous crystals of the sulphuret of zinc, and of the sul phate of barytes; pearl-spar in spheroidal tubercles, upon silver ore ; native gold crystallized, &c.
Of the precious stones of Hungary, the vallies of Ko nigsberg afford emeralds and rubies, and its mountain con tains topazes, hyacinths, and chrysalites ; granites are very common, and rock crystals of various forms ; small crys tals, remarkable for their brilliancy, are found in the county of Marmarosch, and receive the name of Hungarian dia monds. There are also amethysts of various colours, opals, jaspers, and agates.