182 



METALS. 



teristio to bi taken into account, he thinks, is 

 the degree of oxidation of the ore from which 

 the various kinds of iron have been extracted. 

 Malleable iron he supposes to be formed of 

 mixtures of the two kinds of iron which pass 

 into the state of ferricum. Steel he regards as 

 a reunion of the two conditions of iron, the 

 metal being the more perfeot, the nearer the 

 two irons unite in the proportions in which 

 they exist in the mineral state. 



Strengthening of Iron. An English manufac- 

 turer, Mr. E, H. Newby, adds to pig or cast 

 iron an alloy and a flux, to increase its strength 

 and render it less liable to corrosion. The alloy 

 is composed of the following ingredients : 25 Ibs. 

 of zinc, 2 Ibs. of tin, 5 ibs. of copper, and of 

 a Ib. of aluminium, to each 1,000 Ibs. of white 

 iron. The flux for this alloy consists of 2 Ibs. 

 of borax and 1 Ib. of permanganate of potash. 

 These substances are fused together in a closely- 

 covered crucible, and then melted cast-iron is 

 poured in until four or five times the weight of 

 the charge in the crucible has been added, and 

 the whole is then poured into the melted iron 

 to be treated. The iron has been previously 

 drawn off' into a ladle in which have been placed, 

 as a flux, 5 Ibs. of carbonate of baryta and 5 

 Ibs. of cryolite or fluorspar, to every 1,000 Ibs. 

 This flux tends to remove sulphur and silicon. 

 The ladle is then covered with a hood of sheet 

 iron, from which a pipe or flue leads off any 

 zinc fumes that might be generated. There 

 also passes through the hood an earthenware 

 pipe, the lower end of which dips just below 

 the surface of the melted iron. Through this 

 tube the alloy as poured into the molten metal ; 

 and when any boiling or action which results 

 has subsided, the iron is cast into pigs, and 

 these are remelted for use in a cupola foundry. 

 If the iron to be treated is gray, the alloy should 

 by preference be composed of from 30 to 60 

 Ibs. of zinc, 5 Ibs. of tin, 3 Ibs. of copper, and } Ib. 

 of aluminium. Mr. Newby has also made im- 

 provements in the manufacture of wrought iron, 

 consisting of the addition to the iron while it 

 is in the puddling furnace of a mixture of black 

 oxide of manganese (10 Ibs.), oxide of zino (30 

 Ibs.), chloride of tin (5 Ibs.), carbonate of baryta 

 (10 Ibs.), fluor-spar (5 Ibs.), iron filings (5 Ibs.), 

 and gas tar, or asphaltum (10 Ibs.). He claims 

 that the wrought iron thus produced is very 

 strong and pliable, and not liable to acid corro- 

 sion. 



Iron Foil. Hallam & Co., of the Upper 

 Forest tin works, near Swansea, have produced 

 sheets of iron foil weighing only -ffo of a grain 

 per square inch. It would take two hundred 

 of such sheets laid one on top of the other to 

 make up the thickness of an ordinary sheet of 

 note paper. Lloyds, Fosters & Co., had pre- 

 viously made iron foil which weighed only two 

 grains per square inch, and Mr. Parry had ex- 

 hibited specimens weighing only one grain and 

 a half to the same surface. (Mech. Mag.) 



The Preservation of Copper and Iron in Fresh 

 and Sea Water. M. Becquerel's process for 



effecting this object, by availing himself of 

 electro-motive forces, has been introduced with 

 success into the French navy. The process is 

 briefly this, for metals in sea-water: strips or 

 sheets of copper are protected by small bands 

 of zinc fastened to their extremities ; and those 

 of iron by similar small bands of zinc. The 

 action of the sea-water upon the metals is to 

 induce an electric state in the copper and the 

 iron, and to keep them bright over nearly all 

 of their surfaces. In the case of the copper, 

 the entire surface remains bright, except the 

 part near the zinc, which part becomes coated 

 with earthy and metallic deposits when the water 

 is not pure. The problem, therefore, is to 

 arm the metals to be preserved with a metallic 

 protector having an electro-motive force equal 

 to the point where the deposits begin to be 

 inappreciable. A very small quantity of zinc 

 suffices to protect the iron of an iron-clad. In 

 the French navy, these protectors have been 

 arranged so that they can be cleaned and re- 

 newed, when required, without difficulty. In 

 fresh water, the effects present remarkable 

 differences. In the case of a strip of platinum 

 and one of cast-iron, protected by a small strip 

 of zinc, M. Becquerel found that the electro- 

 motive force of the zinc was diminished in 

 the first case by more than one-half, and in the 

 last case by more than a quarter. The differ- 

 ence of the effects is undoubtedly explained by 

 the difference of the conductibility of the two 

 liquids, by means of the different chemical ac- 

 tion which each exerts on the zinc. It has been 

 suggested that cast iron projectiles might be 

 preserved, almost indefinitely, from oxidation 

 by piling them, with occasional strips of zinc, 

 in fosses kept full of water to a constant level. 

 A pile of 9,387 balls of five inches in diameter 

 would require for their preservation bands of 

 zinc, or an appropriate alloy, having a total 

 surface of two square yards. (Mech. Mag., 

 Oct. 12, 1866.) 



/Separating Cobalt from Nickel. M. Terreil 

 has communicated to the French Academy his 

 method of separating cobalt from nickel. To 

 a solution of the two metals he adds ammonia 

 until the oxides are re-dissolved. He then 

 heats the liquor, and to the hot solution adds a 

 solution of permanganate of potash, until the 

 mixture remains violet from an excess of per- 

 manganate. He then boils it for a few minutes, 

 and re-dissolves the oxide of manganese with a 

 slight excess of hydrochloric acid. The liquor 

 is kept hot for some time, and then set aside 

 for twenty-four hours. At the end of that 

 period the cobalt is deposited in the form of a 

 crystalline powder of a beautiful reddish-violet 

 color. This precipitate is roseocobaltic hydro- 

 chlorate, 100 parts of which correspond to 

 22.761 of metallic cobalt, or 28.929 of the 

 protoxide. For very accurate determinations, 

 a known weight of the compound may be re- 

 duced by dry hydrogen and the pure metal 

 weighed. 



The same chemist separates nickel and man- 



