12 



NA TURE 



[November 4. 1897 



Besides* the normal type of binary alloys, in which 

 ■eutectics are observable, there is a second type consisting 

 of alloys of metals which form isomorphous mixtures with 

 €ach other. These alloys, whatever may be their com- 

 position, consist of only one species of crystals, which fill 

 the whole space, the composition and the properties of 

 the alloys usually varying in a continuous manner in each 

 crystal. The number of metals capable of forming 



Fig. 3. — Alloy of tin, 75 per cent. ; antimony, 25 per cent. 



isomorphous mixtures with each other is small, the 

 bismuth-antimony alloys being the only ones out of 

 fourteen series investigated by M. Charpy in which this 

 property was found to exist, but, on the other hand, there 

 are many cases of definite compounds of two metals 

 isomorphous with one of them. Thus, for example, 

 microscopic study has enabled M. Charpy to detect a 

 compound of tin and antimony containing about 50 per 



Fig. 4. — Pure gold. X 1000 diameters. 



cent, of tin and isomorphous with antimony, although the 

 freezing-point curve, worked out by Roland-Gosselin, 

 and consisting of three branches having their concavities 

 upwards, and meeting in two angular points or maxima, 

 gives no direct indication of the relation between these 

 metals. 



In Fig. 2, in which the alloy containing 10 percent, of 



NO. 1462, VOL. 57] 



antimony is shown, the cubical crystals appear to consist 

 of the 50 per cent, alloy set in a eutectic magma. Fig. 3 

 shows the alloy with 25 per cent, of antimony. As the 

 proportion of antmiony in the whole mass approaches 50 

 per cent., these crystals invade the whole field, and 

 numerous minute cracks appear, on the edges of which 

 is seen a secondary crystallisation without the inter- 

 position of an intermediate substance. This structure is 

 characteristic of a pure or homogeneous substance, as in 

 the beautiful micro-sections of pure gold prepared by 

 Osmond and Roberts-.A.usten,^ one of which is repro- 

 duced in Fig. 4. When the proportion of antimony is 

 increased above 50 per cent, a eutectic magma shows no 

 signs of reappearing. Similarly in the tin-antimony 

 series, there is evidence of a compound containing 20 

 per cent, of antimony and isomorphous with silver, and 

 in the silver-tin series a compound containing 30 per 

 cent, of tin also appears to be isomorphous with silver. 

 An investigation of the triple alloys of these metals would 

 be interesting, as probably affording fresh examples of 

 isomorphous series. T. K. R. 



NOTES. 



The Municipal Council of Paris has made a grant of three 

 ihou.sand francs to the fund for the erection of a statue of 

 Lavoisier in Paris. 



M. MouREAU has found in the records obtained at the Parc- 

 St.-Maur Magnetic Observatory, a distinct disturbance evidently 

 produced by the Indian earthquake of June 12. The exact 

 time of the magnetic perturbation registered on that day is 

 11.37 a.m. 



At a recent meeting of the Durham and Northumberland 

 Archaeological Society it was unanimously resolved to obtain a 

 portrait of the president, the Rev. W. Greenwell, F. R.S., 

 Canon of Durham, to be placed in the Cathedral Library, 

 Durham. A strong committee has been formed to further this 

 object, and more than one hundred guineas have already been 

 paid or promised. Further subscriptions are invited, and will 

 be received by Mr. C. Rowlandson, at Messrs. Hodgkin's Bank, 

 Durham, or by Mr. J. G. Gradon, Lynton House, Durham. 



Sir Rutherford Aixock, formerly president of the Royal 

 Geographical Society, died on Tuesday, at the age of eighty- 

 eight. The death is also announced of Prof. C. E. Colby, 

 professor of organic chemistry in Columbia University. 



Dr. G. H. Otto Volger, who died at Sulzbach, in the 

 Taunus, on October 18, aged seventy-five, was at one time a 

 notable figure in scientific and political circles in Frankfurt. 

 A many-sided man, he contributed during his life a number of 

 miscellaneous papers to various natural history and philosophical 

 societies. He made several original contributions to geology, 

 and wrote on the origin of springs, and on meteorological and 

 mineralogical topics. During the time of his greatest activity, 

 while resident in Frankfurt, he founded a society for the cultiva- 

 tion of sciences and arts called the " Freies deutsches Hochstift." 

 Nearly forty years ago, when the old residence in the Hirsch- 

 graben, where Goethe was born, came into the market, he 

 bought it. For a time he lived in it, with the direct object of 

 gradually restoring it, room by room, to the state in which it 

 existed (as described partly in Dichtung und Wahrheit, and 

 partly in Wilhelm Meis/er) during the boyhood of the poet. 

 This done, he made over the Goethe-house to the Hochstift, 

 of which he was then, and for twenty-two years, the president. 



1 Osmond and Robert.s-Austen, "On the Structure of Metals, its Origin 

 and Changes," Phil. Tram., vol. clxxxvii. (1896), A., pp. 417-432. 



