CHEMICAL SCIENCE. 177 



of the hydrate, is of a very deep red color. Its density is 5.576 ; it is 

 soluble only in sulphuric acid, after long digestion and _ subsequent 

 dilution with much water. The solutions of the hydrated oxide in nitric 

 and sulphuric acids are colorless ; that in hot chlorohydric acid, yellow, 

 which color, however, vanishes on cooling. Potash, soda and ammo- 

 nia, give, with solutions of the oxide, white precipitates, which are 

 insoluble in an excess of the precipitant. 



PLATINOID METALS. 



PLATINUM is associated with several other metals in the platinum 

 sand which is found in some gold districts. They have not been found 

 as a distinct deposit in California ; but have been observed in the 

 United States Mint, in the operations of assaying and parting. These 

 associated inetals are palladium, rhodium, iridium, and osmium ; to 

 which we must add the lately discovered metal, ruthenium. They 

 have a sufficient resemblance to be classed together, and are obtained 

 by a similar hydrometallurgic treatment. The grains of iridosmin, 

 found mixed with gold, have been qualitatively examined, and found to 

 contain the new metal, ruthenium, as was observed by Claus in rela- 

 tion to the iridosmin from other localities. Palladium has beoa observed, 

 and, at times, in sufficient quantity to render the gold brittle. The 

 quantities of platinoid metals found in the California gold are small ; 

 about one and a half pound of iridosmin having been obtained from 

 about 25 tons of gold, -nnnnnr ; but the greater part has, of course, 

 passed into the coin, the coarser grains only being left. /. C. Booth, 

 U. S. Mint. 



EFFECT OF ZINC UPON IKON. 



A LETTER from Mr. James Xasmyth to the London Mining Journal, 

 communicates the results of some experiments recently made for the 

 Admiralty, with a view of determining whether old iron, that had 

 been galvanized, or coated with zinc, was rendered unfit for being 

 worked up again. The result of these experiments seems to prove 

 that the iron is improved, instead of being deteriorated, by the zinc 

 combined with it. The following is Mr. Nasmyth's report of the 

 experiments : A piece of galvanized iron wire rope was welded up into 

 a bar, and put to the most severe test. In the first place it was found 

 that, although the iron wire was quite covered with metallic zinc, 

 which although partially driven off in the process of welding, yet, so 

 far from the presence of the metal, or its oxide, presenting any imped- 

 iment to the welding of the iron, (as in the case of lead,) the iron Avire 

 welded with remarkable ease ; and the result was, a bar of remarkably 

 tough, silvery-grained iron, which stood punching, splitting, twisting 

 and bending, in such a manner as to show that the iron was not only 



fj * \r 



excellent, but, to all appearance, actually improved in quality in a very 

 important degree. Encouraged by such a result, a still further and 

 even more severe trial was made, namely, by welding up a pile of 

 clippings of galvanized iron plates, or sheet-iron covered with zinc, as 



