The

rarely, and doubtless accidentally." proportions of lead present in 100 parts of each of the varieties examined were respectively as follows: in No. 1, 1.46; 2, 0.292; 3, 0.079; 4, 0.000; 5, 0.494; 6, 0.106; 7, 1.297; 8, 1.192; 9, 0.823; 10, 1.661; 11, 1.516. The New Jersey zinc was found to contain a sensible quantity of tin, copper amounting to 0.1298 per cent., iron 0.2088 per cent., and an unusually large amount of arsenic. Traces of this were also detected in the white oxide prepared from the ores of the New Jersey mines, and in the red oxide ore itself; but the same ore afforded no clue as to the source whence the copper was derived, a metal of which not the slightest traces were discoverable in the other zincs. None of the samples contained sufficient arsenic to admit of its proportion being determined, and some were entirely free from it, as some of the Belgian and Pennsylvania spelter, but traces of it were met with in other samples from the same regions, indicating that the occasional use of inferior ores, such as blende, intermixed with the carbonates and silicates, might introduce this substance, or possibly it might come over only in the first part of the distillation, and the zinc collected in the latter part might be quite free from it. The Silesian zinc contained minute quantities of sulphur and arsenic; and the English zinc more arsenic than any other, except perhaps the New Jersey. The purest of all the samples was that from Bethlehem, Pennsylvania, some of it yielding no impurity, except a trace of cadmium. The source of a trace of arsenic in another sample is supposed to be in the use of the crust of oxide of zinc from the operations connected with the manufacture of white oxide of zinc, no particular care being taken in that process to reject inferior ores, and this crust being taken to the other works where the metal is prepared and mixed with the selected ores employed for this use, it has thus introduced the arsenic. As the authors of the paper remark, there seems to be no reason why zinc of uniform purity should not be obtained from the excellent ores of the Saucon valley mines.

is indicated in the finely divided black substance which remains floating or sinking in the liquid, when the metal is dissolved in dilute acids. The impurities have been stated by different chemists to consist of a great variety of substances, such as lead, cadmium, arsenic, tin, iron, manganese, carbon, etc. They injuriously affect the quality of the metal for many of its uses; and the presence of one of them, arsenic, is fatal to the highly important use of zinc by chemists, as a reagent in the detection of arsenic in other substances. Arsenic in the form of a sulphuret often accompanies the native sulphurets of zinc, and its oxide, being volatile, is readily carried over with the zinc fumes in the metallurgic treatment of blende, and may thus be introduced into the spelter. It is evidently, therefore, a matter of consequence to know the qualities of the different zincs of commerce, and the exact nature of the impurities they contain. Very thorough investigations. having these objects in view have recently been made in Cambridge, Massachusetts, by Messrs. Charles W. Eliot and Frank H. Storer of Boston, and the results of these, with a full description of their methods of examination, were communicated, May 29, 1860, to the American Academy of Arts and Sciences, and published in the eighth volume of the new series of their Memoirs. Eleven varieties of zinc from different parts of Europe, and made from the ores of New Jersey, and of the Saucon valley, Pennsylvania, were experimented upon, of all of which large samples were at hand. These varieties were the following: 1, Silesian zinc; 2, Vieille Montagne zinc; 3, New Jersey zinc; 4, Pennsylvanian zinc, Bethlehem, Pennsylvania; 5, Vicille Montagne zinc, employed at the United States mint, Philadelphia; 6, zinc of MM. Rousseau, Frères, Paris, labelled and sold as zinc pur; 7, sheet zinc obtained in Berlin, Prussia; 8, zinc made near Wrexham, North Wales; 9, zinc from the Mines Royal, Neath, South Wales; 10, zinc from the works of Dillwyn & Co., Swansea, South Wales; 11, zinc from the works of Messrs. Vivian, Swansea. All of these, except the Pennsylvania zinc, furnished an insoluble residue, which was found to consist chiefly of metallic lead, and this proved to be the principal impurity of all the samples examined; "the carbon, tin, A large portion of the zinc of commerce copper, iron, arsenic, and other impurities is furnished by the works of the Vieille found in the metal by previous observers, Montagne Company, established near the occur either in very minute quantities, or frontier of Belgium and Prussia, chiefly in

EUROPEAN MANUFACTURE.

seven large smelting establishments belonging to the Vieille Montagne Zinc Mining Company, on the borders of Belgium and Prussia, comprising 230 furnaces. The an

ter, of which 23,000 tons are converted into sheet zinc, and about 7000 tons are rolled at mills not the property of the company. They also manufacture oxide of zinc in three establishments devoted to this operation, to the amount of about 6000 tons annually. The company also purchases spelter very largely.

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the province of Liege of the former country. A large number of mines are worked in this region, the most important of which is that of the Vieille Montagne or Altenberg, situated in the village of Moresnet, betweennual product of these is 29,000 tons of spelAix-la-Chapelle and the town of Liege. It is said that the great body of carbonate of zinc found here was worked as long ago as the year 1435, and that for four centuries it was not known that the ore was of metallic character, but it was used as a peculiar earth adapted for converting copper into brass. The ore lies in a basin-like depression in strata of magnesian limestone, and is much mixed with beds of clay intercalated among its layers. The ore is chiefly carbonate mixed with the silicate and oxide of zinc. Some of it is red, from the oxide of iron intermixed, and this produces only about 33 per cent. of metal. The purer white ore yields about 46 per cent., and is moreover much preferred on account of its working better in the retorts. The furnaces employed in the distillation of these ores are constructed upon a very large scale, and on a different plan from those in use in Great Britain. The general character of the operations, however, is the same. The ores are first calcined, losing about one fifth of their weight. They are then ground in mills, and charges are made up of 1100 lbs. of the powdered ore mixed with 550 lbs. of fine coal. The mixture being well moistened with water, is introduced into cylindrical retorts, which are three feet 8 inches long and 6 inches diameter inside, set inclining outward, to the number of 42 in a single furnace, and 4 such furnaces are constructed in one stack. The open end of each retort connects, by means of an iron adapter 16 inches long, with a wrought-iron cone, the little end of which, projecting out from the furnace, is only an inch in diameter. After the charges have been sufficiently heated, the sublimed zinc condenses in the neck of the retort and in the adapter and cone. The last two are then removed, and the zinc and oxide are collected from them, and the liquid metal in the neck of the retorts is drawn out and caught in a large ladle, from which it is poured into moulds. The zinc thus obtained is remelted before it is rolled. Two charges are run through in twenty-four hours, each furnace producing from 2200 lbs. of ore about 620 lbs. of metal, which is about 30 per cent. From a late report of these operations it appears that there are

The metallurgy of zinc has, within a few years past, become an important branch of industry in Upper Silesia on the borders of Poland, and not far from Cracow. In 1857 there were no less than 47 zinc works in this part of Prussia, one of which, named Lydogniahütte, at Königshütte, belonged to the government, and the remainder were owned by private companies and individuals. In that year their total production was 31,480 tons of spelter, valued at about 17,660,000 francs. Many of the establishments belong to the Silesian Company, which also owns several coal mines near their works, and a number of zinc mines. The government works are supplied with ores from their own mines, and also from all the others, being entitled to one twentieth of their product. From a description of the operations published in the sixteenth volume of the Annales ds Mines, fifth series, 1859, it appears that the processes are the same which had been employed for full twenty years previously, and each establishment presents little else than a repetition of the works of the others. The furnace in use is a double stack, furnished along each side with horizontal ovens, into each of which three muffles or retorts are introduced. These are constructed of refractory fire clays, and are charged, like the retorts of gas furnaces, by conveying the material upon a long charger or spoon into the interior. Their dimensions are about 4 feet long, 22 inches high, and 84 inches wide, and the weight of the charge introduced is only about 55 pounds. The ovens on each side of the stacks contain as many as 20 and sometimes 30 retorts. The same stack contains besides, 1st, an oven in which the ores belonging to it are roasted for expelling the water and a portion of the carbonic acid they contain (a process in which they lose about

their weight); 2d, an oven for baking the retorts, each establishment making its own; and 3d, a furnace for remelting and purifying

the zinc obtained from the retorts. Several stacks are arranged in a large building with close walls and open along the top of the roof to allow the smoke to escape. On one side, connected with it, are the workshops in which the muffles are made and various other operations are carried on.

mixed with oxide of zinc from previous operations, with the dross from the crucible employed in remelting, with the incrustations from the muffles and their connections outside the furnaces, and in fine with cinders that have fallen through the grates, these last making about the bulk of the charge. The principal zinc mines are in the vicin- The workmen having discharged a muffle of ity of Beuthen, and are found in the magne- the liquid zinc and oxide remaining from the sian limestones of the new red sandstone previous operation by drawing them forward, formation. They are connected with the so that they fall upon an iron shelf placed zinc works, which are principally near Kö- | below to catch them, and having repaired nigshütte, by branch railroads connecting any cracks and holes in the muffle, they inwith the principal line of road between troduce the new charge in small portions at a Tarnowitz and Kattowitz. The ores are time, and immediately adjust the outer conchiefly carbonates, always mixed with much nection, which is also of earthenware bent oxide of iron, which is sometimes present to down at a right angle, and close up the the extent of 20 per cent., and with them is openings in front. The zinc soon begins to also associated more or less silicate of zinc, distil over, and drops down upon the iron blende, galena, and cadmium. Their per- shelf, forming pieces of all shapes; and it is centage of zinc is very variable, rarely reach- more or less mixed with oxide colored yel ing 35, and probably averaging 21 or 22 per low by the oxide of cadmium. When recent. Much that is worked does not exceed melted and run into moulds, the spelter is 12 per cent. They lie in irregular deposits, stated to have about the following composiand it is found that their yield of zinc has tion: zinc, 97.50, cadmium, 1.00, lead, 0.20, been gradually falling off, so that it is now arsenic, 0.84, sulphur, 0.05, together with only about two fifths of what it was formerly. traces of tin, iron, and carbon; but the charThis low yield involves a large consumption acter and proportion of the impurities are of fuel, which is 20 tons for one of zinc ob- probably very variable. The expenses of tained; and if this deterioration continues, the manufacture at the royal works amountthe mines must some time hence be aban-ed for the year 1856 to 48.60 francs the doned. The coal employed in working the metrical quintal (220.47 lbs.), and in 1858 ores is of poor quality, burning without to 54.84 francs; consisting in the latter flame; but it leaves no cinder, and is pro-year of the following items: ore, 26.84; cured from mines very near the works, and fuel, 14.30; labor, 7.00; materials employat the extraordinary low price of 6 to 7 francs the 1000 kilogrammes (about one ton). The retorts are charged every 24 hours with roasted ore reduced to the size of nuts, and

ed, 3.70; general expenses, 3.00. The operations of the Silesian Company at their several works for the first half of the year 1858 are thus presented :

roof constructed during the last twenty-five years. In laying the sheets great care is taken that the metal has sufficient room to expand and contract by change of temperature; and especially that it is fastened with zinc nails, and is allowed to come nowhere in contact with iron-even with nail heads. The purer the metal the longer it lasts.

The estimate of 67,000 tons as the total annual production of zinc is probably too small for Europe alone. Taking the product above given of the works of the Vieille Montagne Company, viz., 29,000 tons, and that of the Silesian furnaces, 31,480 tons, there remain only 6,520 tons to be divided among the other zinc-producing countries. These are Poland, on the borders of Silesia, the Besides the uses named for this metal, it annual production of which is usually given is employed for coating sheet iron, making as 4000 tons; England, which has rapidly what is called galvanized iron; for pipes for advanced from 1000 tons of spelter per an- conveying liquids; for baths, water-tanks, num to 6900 tons in 1858; Austria, which milk-pans and pails, plates for engraving; produces 1500 tons; Sweden, 40 tons; and the for galvanic batteries; for nails, spikes, and Hartz 10 tons. Zinc, it is believed, is also wire; for signs; music printing; and for the manufactured to some extent in Spain. The cornices of buildings. It has also been cast European production would, therefore, seem into statues, in imitation of bronze. The to exceed 73,000 tons, and for the total Vieille Montagne Company sent to the Great production of the world, that of the United Exhibition in London a statue of Queen VicStates and of China should be added. Of toria, which with its pedestal of zinc was the extent of the manufacture of the latter twenty-one feet high. By a process somecountry we know nothing. The United what like lithography, called Zincography, States produces of oxide of zinc and spelter drawings, old engravings, and autograph letover 7.000 tons, and imports 12,000, annually. ters are transferred to it, and after treatment The value of the ores at different costs of with acids, printed from a raised surface. A the metal is given in the following_recently modification of this process called Photozincprepared table from one of the Europeanography, accomplishes the difficult task of houses:

printing from a photograph. Zinc is also an important reagent in chemical operations, and is employed with sulphuric acid to decompose water for obtaining hydrogen gas.

ZINC PAINT.

White oxide of zinc was first récommended as a substitute for white lead by the celebrated Guyton de Morveau about the close of the last century, during his investigations on the subject of lead poisoning; and to him it was suggested by CourThe high tois, a manufacturer at Dijon. price of zinc at that time, and ignorance respecting the proper manner of using the oxide of zinc, prevented its introduction. It was many years after this that methods of producing it as cheaply as white lead were devised by M. Leclaire, a house-painter of Paris; and he also first prepared to use with it a series of yellow and green unchangeable colors, to replace those before in use having noxious bases of lead, copper, or arsenic and also a drying oil, prepared by boiling linseed oil with about five per cent. of oxide of manganese. His process, which is still the one in general use in Europe, is based on the treatment of the metal instead of the ore, as practised in this country, and scarcely any white oxide of zinc is there made by

;

strated in Europe, and the practicability of producing it economically from the red oxide was shown, a company was organized in New York under the name of the New Jersey Zinc Company, for the purpose of carrying on this manufacture upon a large scale. This association was incorporated by the Legislature of New Jersey, February 15, 1849, and the report of their operations, made December 31, 1853, by their president, C. E. Detmold, Esq., showed a production, for 1852, of 2,425,506 lbs. of oxide; and for 1853, of 4,043,415 lbs.; and the total production for 10 years, ending with 1860, has amounted to above 19,500 tons. Their works were established at Newark, N. J., to which place the ores are brought by the Morris' and Essex canal; and the anthracite consumed in the manufacture is also delivered by water transportation. The company has forty furnaces, that may be kept in constant operation. The character of the process is like that which will be given below, as conducted by the Passaic Mining and Manufacturing Company.

any other method. The furnaces employed are similar to those for producing the metal, or like those of the gas works. When the retorts set in these furnaces have become very hot, they are charged with the ingots of zinc. The metal soon melts, and its vapor passes off through the outlets of the retorts, where it meets a current of air, and both together are drawn on through the condensing apparatus either by the draught of a chimney, or by an exhausting fan at the further extremity of the apparatus. The metallic vapors become oxidized by mixing with the air, and are converted into a light, flaky, white powder, which is the oxide of zinc. The arrangements for condensing and collecting this are similar in principle to those employed for the same purposes in the American process. By making use of the metal in retorts, instead of subliming it from ores contaminated with their own impurities, and mixed with the coal required for conducting the process, a much purer oxide of zinc is obtained; and by selecting the purest sorts of spelter, the beautiful article, called by the French blanc de neige, The success of the enterprise of the New or "snow-white," is produced, which is Jersey Zinc Company, and the discovery in employed by painters in the place of the 1853 of the great beds of silicate and car"silver-white." With the use of other zinc, bonate of zinc in the Saucon valley, Pennthe product is fit to be substituted for the sylvania, led to the organization in that year best white lead. But if the metal has been of the l'ennsylvania and Lehigh Zinc Commade from ores containing cadmium or iron, pany, and the crection of furnaces for makor if old zinc has been introduced to which ing the oxide at Bethlehem, on the Lehigh any solder adheres, according to the French river. The operations were conducted by chemists oxides of other metals are pro- Samuel Wetherill, Esq., by a patented procduced, and are taken up in small quantities ess of his own invention, and at a contract with the zinc vapors, imparting to the oxide price of $50 per ton; the ore being deliva slightly yellow or greenish tint, which ifered by the company at the works for $1.50 not very decided may however disappear when the paint is mixed; but the experience of American manufacturers does not accord with this explanation.

per ton. About four tons were consumed to the ton of oxide. The company mined up to January, 1860, about 60,000 tons of ore, and at that time were manufacturing about 320,000 lbs. of oxide of zinc per month.

The manufacture of white oxide of zinc direct from the ore is a purely American A third company was established in 1855, process, established by the experiments of called the Passaic Mining and Manufactur Mr. Richard Jones of Philadelphia in the ing Company, and their works, constructed year 1850. The great bodies of the rich at Communipaw, on the Morris canal ncar ores of northern New Jersey had at various Jersey City, went into operation in June of times, for the past two centuries, attracted that year. They obtained their ores both the attention of many persons interested in from the mines of red oxide in Sussex metallurgical operations; and of late years county, and from the Saucon valley mines in numerous attempts had been made to devise Pennsylvania. They employed 24 furnaces, some method of converting them to useful built in 3 stacks, of 8 each, in which they purposes. Zinc, however, was a metal not were arranged like ovens, half of them openmuch in demand, and nothing was known ing on one side and half on the opposite of the useful qualities of the white oxide. side. Each one was about 6 feet in depth When the value of this had been demon- (from front to back), 4 feet in width, and