September 24, 1914] 



NATURE 



109 



in which there is recrystallisation in the solid 

 state. 



Following the brilliant theory of Osmond, the alloys 

 of iron and of nickel in the case of meteorites ought 

 to follow an analogous diagram. 



Not long since this theory was entirelj- confirmed 

 by the beautiful experiments of Benedicks. We see 

 that in the two cases, in that of meteorites as well as 

 in that of terrestrial iron, the appearance of these 

 Widmanstatten figures is connected with two funda- 

 mental facts — the character of the primary octahedral 

 crystallisation, and the separation of the solid solution 

 into different phases during recrystallisation. 



This structure, therefore, is not in the least con- 

 fined to iron and its alloys ; it might be equally well 

 encountered in each alloy or each metal which crystal- 

 lises in the regular system, and in which, after solidi- 

 fication, the crystallised solid solution throws out 

 secondary deposits, that is to say, is subject to re- 

 crystallisation. In a pure metal there would be an 

 allotropic change in the solid state, as, for example, 

 the iron shown in Fig. 4 — in an alloy, the separation 

 of a new phase ; and as diagrams of this kind are well 

 known, it ought not to be at all difficult to find 

 examples of the Widmanstatten structure in alloys 

 other than iron. 



To this class of alloys belong, for example, the 

 different alloys of copper, particularly the brasses and 

 bronzes. Gulliver, in his interesting volume on 

 metallic alloys,^ gives numerous examples of this, 

 mentioning the separation of SnCuj in the alloys of 

 copper and tin, of SbCu^ in those of copper and anti- 

 mony, of the constituent beta in brasses with about 

 35 per cent, of zinc (see Gulliver, Fig. 200), or of delta 

 in the alloys with 70 to 75 per cent, of zinc (see 

 Gulliver, Figs. 205 and 206). The author is able to 

 reproduce here a photograph (Fig. 5) of a brass 

 containing 55- 1 per cent, of copper (cooled in sand and 

 annealed), which was kindly sent to him by M. L. 

 Guillet. This photograph has great interest, as it 

 shows the action of reheating on the Widmanstatten 

 structure. 



Fig. 6 serves as another example of this structure, 

 for which the author is indebted to. M. Chouriguine ; it 

 represents an alloy of platinum-aluminium. M. 

 Chouriguine,' in studying these alloys, found a trans- 

 formation in the solid state, and this transformation 

 manifested itself in a very marked Widmanstatten 

 structure. 



It is perhaps useful to remark that the first condi- 

 tion, that is to say, the primary octahedral crystallisa- 

 tion, is not difficult to find, for the majority of metals 

 and alloys crystallise either in the regular or in the 

 hexagonal system. In the last case the character of 

 the Widmanstatten figures may differ in detail whilst 

 preserving the same general aspect, as can be seen 

 from Fig. 7,'' representing a sample of zinc after 

 melting and slow cooling. 



These few examples, though taken somewhat hap- 

 hazard, serve nevertheless as illustrations of the great 

 extent to which the W'idmanstatten structure exists in 

 different alloys and metals. In the alloys of iron the 

 Widmanstatten structure has an important industrial 

 interest, as it gives rise to very poor mechanical pro- 

 perties in the case of cast steels and in overheated 

 steels. 



The chief object of this brief communication is to 

 direct the attention of metallurgists and engineers to 

 the study of alloys, other than iron, from the point 

 of view of the production and the removal of the 

 Widmanstatten structure. 



8 " Metallic Alloys,' G. H.Gulliver. 



9 " Sur les alliages du plaline avec raluminium," by M. Chouriguine. 

 Revue de Metallurgie, 1912, p. 8735. 



1" 1 his photograph was taken by M. Timoth^ieff. 



UNIVERSITY AND EDUCATIONAL 



INTELLIGENCE. 



Belf.ast. — Prof. R. H. Yapp has been appointed 

 professor of botany in the Queen's University, Mr. 

 C. W. Valentine professor of education, and Sir Hiram 

 Shaw Wilkinson pro-Chancellor of the University. 



Glasgow. — Dr. W. J. Dilling, of .Aberdeen, has 

 been appointed to the new "Robert Pollok" lecture- 

 ship, tor research in materia medica and pharma- 

 cology, at the University of Glasgow. 



The University Court has given leave of absence to 

 Mr. A. Stevens, assistant in the department of geo- 

 graphy, in order that he may accompany Sir Ernest 

 Shackleton's Antarctic Expedition as geologist. The 

 Court has also placed at his disposal a petrological 

 microscopic equipment for the purposes of the expedi- 

 tion. 



Temporar}- arrangement have been made for carry- 

 ing on the work of a considerable number of the lec- 

 turers, assistants, and examiners, who, in consequence 

 of the war, are absent on duty or detained abroad. 



Dr. D. a. Campbell, of Halifax, has, says Science. 

 promised 12,000/. to endow a chair of anatomy at 

 Dalhousie University, Halifax, in memory of his son, 

 the late Dr. George Campbell. 



The council of the Senate of the University of Cam- 

 bridge has offered to professors, teachers, and students 

 of the University of Louvain such facilities in the way 

 of access to libraries, laboratories, and lectures, to- 

 gether with the use of lecture-rooms, as may secure 

 the continuity of the work of that University during 

 the present crisis. Hospitality in the way of living 

 accommodation and so forth will probably be offered 

 by the individual colleges and by private residents. 

 The professors of the University of Oxford have 

 offered a home for the winter to the young children 

 of the professors of the University of Louvain ; and 

 the academic staff of University College (University 

 of London) offers hospitality to about seventy mem- 

 bers of French and Belgian universities, whether pro- 

 fessors, teachers, or students, men or women, who 

 may find it necessary to take refuge in this country. 



A WELL illustrated prospectus for the present session 

 of the Municipal Technical Institute, Belfast, has been 

 issued. The chief object of the institute is to provide 

 instruction in the principles of the arts and sciences 

 which bear upon the trades and industries of Belfast, 

 and to show bv experiment how these principles may 

 be applied to their advancement. The evening classes 

 are designed for persons engaged during the day in 

 handicrafts or business who desire to supplement and 

 develop the knowledge and experience they have gained 

 in the workshop and warehouse. It is satisfactor>- to 

 notice that the prospectus insists that the successful 

 prosecution of special studies is in proportion to the 

 student's knowledge at the beginning of such work 

 of the elements of mathematics and drawing. The 

 day technical course provides instruction in the science 

 and technology- of mechanical and electrial engmeer- 

 ing, the textile industries, and pure and applied chem- 

 istrv ; and it gives a sound training to youths who 

 aim' at filling responsible positions in these departments 

 of activitv. We notice that the Queen's University of 

 Belfast and the Belfast Corporation have entered into 

 an agreement wherebv the institute is recognised as 

 a college in which students of the University may 

 studv to qualifv for a degree or diploma in science 

 of the Univers'itv. It is impossible in view of the 

 completeness and multiplicity of the arrangements 

 which have been made to meet the needs of every 

 class of student, to mention them all, but attention 



NO. 2343, VOL. 94] 



