CHEMICAL SCIENCE. 



229 



The quantitative anatysis of the alloys gave the following per-centage 

 results : 



These results show that bronzes of the most different colors possess nearly 

 the same composition. The action of acid shows likewise that their color is 

 owing to different degrees of oxidation. It appears therefore probable, that 

 in the preparation of bronze powder, a certain alloy is used for all, and that 

 the colors are produced by heating to different temperatures. This Hr. 

 Konig found to be the case. In his experiments with the above-named 

 powders, No. 1, when heated, presented successively all the prismatic colors, 

 and acquired a fine dark violet. Most of the other bronzes presented the 

 same character, and when the heat was maintained, lastly became black, 

 from complete oxidation. 



Hr. Ko'nig is of opinion that the fat in these bronze powders originates 

 from the use of fat in their preparation, for the purpose of insuring uniform 

 temperatures. Tallow or fat oils would not ansAver for this purpose, since 

 they would, in course of time, cause an oxidation of the copper. Wax, and 

 especially paraffine, appear better adapted for this purpose. He states that 

 0.5 per cent, of either substance, mixed with the bronze powder in a shallow 

 pan, is sufficient. 



The mechanical subdivision of the alloy is affected by rolling and ham- 

 mering, as in the preparation of goldleaf, and then grinding the leaves of 

 metal, with water, between stones. 



Hr. Konig has endeavored to prepare these bronzes in the wet way, by 

 reducing the metal; but has not succeeded in obtaining any satisfactory 

 results. The only substance of this kind which he was able to prepare in 

 the wet way, is that called " iron black," which is used for coating gypsum 

 figures, in order to give an appearance similar to gray cast-iron. This consists 

 of very finely divided antimony precipitated from solution by means of zinc. 



ON TWO NEW METALS IN SWEDISH MAGNETIC IRON ORE. 



Professor Ullgren, in a recent communication to Liebig's Annalen, states 

 that he believes he has detected in a magnetic iron ore from near Asker- 

 sund, Sweden, two metals one of an electro-negative, and the other of an 

 electro-positive nature both possessing properties which justify the assump- 

 tion that they have not hitherto been known. The ore in question, when 

 added to good ores in smelting, is said to cause a high degree of deterioration 

 in the iron obtained. 



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