METALS. 



ganose from a solution of those metals l>y 

 :i with ammonia, and 



,'>-niuui^a[iato of potash, or 



. i!>-, aii-l boiling tho mix- 



Tho manganese IB now precipitated, and 



In .-.iliitioii, from which it 



;>ar.ited as sulphide or oxide. 



; intse. Prof. Henry How, in 



raouotioDJ of tho Nova Scotia Institute 



>os a now ore of man- 



is sent from Parrsborough, and 



another locality to the east of Halifax, 

 found in lumps, mixed with stones. 



. Mark, earthy substance, in tho form of 



\ J lumps and grains. The sample exam- 

 ined contained a good deal of water, and when 

 dried, 5G per cent, of binoxide of manganese, 

 with traces of cobalt, which are usually found 

 in this species. Neither of these would be 

 valuable as ores of manganese, but would prob- 

 ably bo valuable as paints. Manganese is often 

 mixed with bog iron ore, and then fornis de- 

 posits of a- brown or chocolate color, called 

 ochres, or mineral paints. In the Bridgewater 

 paints of this character, Prof. How found 11 

 per cent, and in the Chester paints about 20 

 per cent., of binoxido of manganese. 

 Alloys of Manganese. The German chem- 

 /.irer has prepared alloys of manganese 

 with iron and copper, which prove to have 

 valuable properties, and are susceptible of many 

 useful applications. For alloys of iron and 

 manganese he mixes pulverized oxide of man- 

 ganese, charcoal dust (corresponding in quantity 

 to the oxygen of the oxide) and cast-iron filings 

 or turnings. The mixture is put into a graphite 

 crucible, covered with a coating of charcoal 

 dust and sea salt, and exposed for a few hours 

 to a white heat. After cooling, a metallic 

 homogeneous mass is found at the bottom of 

 the crucible. The most important of the alloys 

 aro those containing two equivalents of manga- 

 nese to one of iron, and four equivalents of 

 manganese to one of iron corresponding to 

 t '.;.:] per cent, and 79.7 per cent, of manganese. 

 Both are harder than tempered steel, and ca- 

 pable of receiving a high polish ; melt at a red 

 heat, and are easily poured ; do not oxidize in 

 water, and only superficially in air, and are of 

 a shade between steel and silver. Alloys of 

 copper and manganese are obtained in the same 

 manner, resembling bronze, but much harder 

 nnd more durable. Alloys with tin resemble 

 silver, are very fusible, durable, and easy to 

 work. The iron and manganese alloy furnishes 

 a convenient means of adding a given amount 

 i if tho latter metal to iron or steel; by the ad- 

 dition of from 1.10 to 5 per cent, very satisfac- 

 tory results art obtained. 



h's'luction of Chromium and Manganese. 

 M. Eoussin states that he has observed that 

 a sodium amalgam, shaken up with an acidu- 

 lous solution of a salt of chromium or man- 

 ganese, changes to an amalgam of those metals, 

 and that when this amalgam is distilled in a 

 current of hydrogen, after having first been 



carefully washed in acidulated water, the pare 

 metal is left in the form of a pulverulent 

 sponge. Tho amalgam of manganese is opalet- 

 and crystalline; that of chromium more 

 iluid, and less variable at ordinary temperatures. 

 When tho chromium amalgam is heated in a 

 small porcelain capsule in the air, the mercury, 

 as it flies off in vapor, carries with it particles 

 of chromium, which take fire, producing a sin- 

 gular scintillation, best observed in a darkened 

 room. Finally, the chromium remaining in the 

 capsule suddenly becomes incandescent, and 

 burns to oxide. 



The Estimation of Silver Oxide as Metallic 

 Silver. A new mode of performing this opera- 

 tion is reported by Sir Alexander Classen to the 

 Journ. far Prakt. Cliemie., vol. iv., p. 217. 

 Ho evaporates a solution of nitrate of silver 

 with sulphuric acid until all the nitric acid is 

 driven off. The sulphate of silver is then dis- 

 solved in hot water, and a stick of cadmium 

 placed in tho solution. The cadmium reduces 

 the silver oxide, and the metallic silver collects 

 in a mass, which can be washed with hot water 

 by decantation without loss. The acid liquor 

 should then be heated until no combustion of 

 hydrogen takes place. In the clear liquid 

 which remains no trace of the silver can now 

 bo recognized. Cadmium being but slightly 

 soluble in dilute acids, the same piece of metal 

 will servo for several operations without even 

 losing the metallic lustre of its surface. Freshly 

 precipitated chloride of silver may be reduced 

 in the same way. 



Improved Process for separating Lead from 

 Silver. In a factory at Holtrappel an improve- 

 ment has been introduced in the separation of 

 silver and lead as follows : the melted lead is 

 poured into a crystallizing pan, and its surface 

 covered with small fragments of coke, upon 

 which a thin stream of water is permitted to 

 run. The mass is slowly agitated with a cir- 

 cular motion, which ensures the equal moisten- 

 ing and cooling of tho whole surface. In about 

 an hour the lead loses its fluidity, and forms a 

 solid crust, which envelops the small pieces of 

 coke. The stream is now turned off, the agita- 

 tion stopped, and the unsolidified lead, rich in 

 silver, is run off at tho bottom. Before com- 

 plete solidification takes places, strong iron 

 hooks are inserted in the mass, and it is lifted 

 by a crane from the pan, which is then ready 

 for a second operation. 



Action of Acids upon Metals and their Al- 

 loys. At the Juno meeting of the London 

 Chemical Society a paper was read detailing 

 the investigations made by Dr. F. Grace Calvert 

 and Mr. Johnson on this subject. Pure zinc 

 washed with alcohol and dried, was scarcely 

 acted upon by SO,, HO, in the cold, while a 

 similar piece, exposed to the air for a week, and 

 slightly oxidized, dissolved to the extent of 

 three grammes in the same acid in two hours. 

 Monohydrated sulphuric acid dissolved alloys 

 of copper and zino uniformly, when the brass 

 was composed of those metals in the proportion 



