METALS. 



473 



impinge on a paper moistened with acetate of lead. 

 The evolution of sulphuretted hydrogen, after a very 

 little experience, moreover, is just as easily detected 

 by the smell. Experiments were also made with the 

 oxalate of iron, by redissolving it in hydrochloric acid 

 and reprecipitating with ammonia, or by dissolving 

 the oxide obtained, by heating the oxalate of iron in 

 hydrochloric acid, and reprecipitating again by ox- 

 alate of ammonium. In all these cases the reduced 

 iron contained sulphur. The second series of exper- 

 iments were made with the iron obtained from the 

 crystalline oxide of iron. It is well known that, when 

 protosulphate of iron is fused with chloride of sodi- 

 um, a crystalline oxide is obtained. For our experi- 

 ments it was of course necessary to perform this opera- 

 tion in a platinum crucible, but it was found that the 

 iron thus obtained contained a small quantity of pla- 

 tinum. We therefore employed, instead of chloride 

 of sodium, the sulphate or sodium, and obtained an 

 oxide which, after haying been thoroughly washed 

 and reduced, gave an iron containing sulphur. Ex- 



w^v. owning "by ammonia, washing the oxide, and 

 reducing it. The iron thus prepared contained sul- 

 phur. The next experiments were made by dissolv- 

 ing the crystalline oxide in hydrochloric acid, digest- 

 ing with chloride of barium for several days, decanting 

 and filtering through papier (previously digested with 

 dilute nitric acid) ; precipitating by ammonia (dis- 

 tilled from ammonia to which chloride of barium had 

 been added), washing, and reducing the oxide. The 

 iron thus prepared still contained sulphur. The 

 third series of experiments were made with sublimed 

 proto- or sesqui-chloride of iron, by dissolving it in 

 water, precipitating with pure ammonia, washing, and 

 reducing in^ hydrogen. All the specimens thus pre- 

 pared contained sulphur. The sublimed chloride was 

 obtained sometimes from the red oxide, prepared by 

 heating the oxalate of iron obtained as above de- 

 scribed, or from the crystalline oxide by dissolving it 

 in hydrochloric acid, digesting with chloride of bari- 

 um, evaporating to dryness, and subliming either in 

 platinum vessels or in porcelain tubes, or in clay re- 

 torts, either alone or in a current of chlorine or of 

 hydrochloric acid. In the fourth series of experi- 

 ments, the metal produced by either of the above 

 methods was submitted in the platinum tube, while 

 red hot, alternately to the influence of hydrogen 

 and oxygen or hydrogen and steam, or of vapors of 

 nitric acid and hydrogen, or of ammonia vapors, oxy- 

 gen, and hydrogen. In all the cases the operation 

 was repeated several times, and ? although sulphuret- 

 ted hydrogen was given oft during these operations, 

 yet the iron always contained sulphur. Further ex- 

 periments were made by dissolving the purest iron 

 in dilute acetic acid, and evaporating to dryness, and 

 heating. The metal obtained still contained sulphur. 

 Also the iron obtained from ferrocyanide of potas- 

 sium was found to contain sulphur. In fact, we have 

 never made or found a specimen of 'iron which did 

 not contain sulphur. Even electrotype iron, said to 

 be prepared from chloride of iron, evolved, by dis- 

 solving in dilute hydrochloric acid, a very appreci- 

 able quantity of. sulphuretted hydrogen. 



The authors have made upward of seventy 

 experiments, and, although they have not yet 

 been able to devise a method for preparing 

 iron free from sulphur, they do not despair of 

 accomplishing that result. 



Decarbonizing Cast Iron. Mr. Eichardspn, 

 of Glasgow, has patented a process for burning 

 out the carbon from crude iron, which may be 

 described as follows : When the ore is reduced 

 in the blast-furnace, it is run off into a proper 

 vessel; a blast of air, at a pressure of four 

 pounds on the square inch or upward, is intro- 



duced into the melted mass, through a hollow 

 rabble or stirring-rod. The effect is, that the 

 impurities are rapidly driven off, and the metal 

 pbtained^is specially adapted to produce cast- 

 ings of high quality. It may be run into moulds 

 immediately after purification, or may be 

 cooled and afterward melted for casting, and 

 for this purpose it may be used alone, or with 

 a portion of pig-iron, or spiegel-eisen, or with 

 any other compound of carbon and iron, which 

 may be mixed with it in the molten or solid 

 state, according to the temperature of the 

 liquid metal in the receptacle. Crude steel 

 may also be produced by the same process ; 

 and, to get a finer steel after the metal has been 

 purified in the manner described, it may be 

 run off into a chamber of a puddling-furnace, 

 where unmelted spiegel-eisen OF other com- 

 pound of carbon and iron is added to recarbon- 

 ize the metal, and so convert it into steel, which 

 may be run off into ingot-moulds. To insure 

 a thorough mixture of the carbonized com- 

 pound with the purified melted metal, the 

 charge is stirred up in the puddling-chamber 

 with an ordinary rabble, and, if desired, pow- 

 dered manganese or other oxidizing compound 

 may be added through a tubular rabble previous 

 to the addition of the carbonized compound of 

 iron. Steam may be used as the oxidizing 

 agent. 



Alloy of Tungsten and Iron. A correspond- 

 ent of the London Chemical News gives an 

 account of the composition of some masses of 

 pig-iron, which, having been thrown into a 

 furnace in Dublin, could not be brought to a 

 sufficiently liquid state for casting. Fragments 

 of the iron were analyzed, to ascertain the 

 cause of the difficulty, and the result of the in- 

 vestigation is thus reported: The pieces had 

 a metallic lustre, or color, similar to gray iron, 

 were brittle, very hard, and possessed in sev- 

 eral parts a vesicular structure. Their specific 

 gravity was as high as 10.125 ; they were at- 

 tracted by the magnet, but in a considerably 

 less degree than pig-iron. In muriatic acid 

 they were partially dissolved, with evolution 

 ofhydrogen. The solution, however, was in- 

 complete, and there remained undissolved more 

 than half the weight of the metal subjected 

 to the action of the acid. A second portion 

 of this metallic material from the foundery was 

 acted upon by aqua regia, when a yellow in- 

 soluble substance made its appearance, which 

 was found to be tungstic acid, as it exhibited 

 the following properties: It was insoluble in 

 water or acids, and after ignition acquired a 

 straw-yellow color ; but, when placed upon a 

 filter and washed with water, it became white 

 and then gradually passed through the filter. 

 In water of ammonia it readily dissolved, and 

 the solution, when placed in contact with zinc 

 and supersaturated by muriatic acid, gave a 

 white gelatinous precipitate, which rapidly ac- 

 quired a blue color. A drop of the ammoni- 

 acal solution dried on a platinum wire, and, 

 fused in the reducing flame of a blowpipe with 



