428 



NA TURE 



[March 3, 1898 



THE STRUCTURE OF CRYSTALS} 



TT is impossible here to do more than call attention to these 

 ■^ two memoirs ; the subject with which they deal is too 

 intricate to be intelligible without the aid of diagrams. 



The author of the first appears to hold quite peculiar views on 

 the nature of valency and chemical combination Each atom is 

 surrounded by a "sphere of action," and this represents the 

 volume of the element ; whereas the volume of a compound 

 molecule is less than the sum of the volumes of its components, 

 for their spheres of action are supposed to interpenetrate to a 

 certain extent when combination takes place. Their partial 

 interpenetration gives rise to a complex surface of action for the 

 molecule, which may be of a polar character, and approximates 

 in form to a sphere when the molecule consists of a large number 

 of atoms. Crystallisation is due to the attractive juxtaposition 

 of such polar molecules. For the author's general views the 

 reader is referred to his previous work, " Die Kraft und Materie 

 in Raume." 



The present memoir is an elaborate study of the development 

 of a number of complex forms by the superposition of spheres 

 layer by layer on one or other of a few simple " embryos "; for 

 example, on a tetrahedron composed of four equal spheres in 

 contact. The whole process is illustrated by twenty six excellent 

 plates, which appear to be photographs of skilfully constructed 

 stacks of balls. On all matters the author expresses himself 

 with remarkable confidence, and claims to have solved the 

 problem of crystallisation. 



We doubt, however, whether all the types of crystalline 

 symmetry are covered by the author's hypotheses, and some 

 of his groups appear to be incompatible with what is known of 

 crystals. 



Mr. Barlow's first communication on the subject of crystalline 

 structure was made to this journal (vol. xxix. p. i86) in 1883, 

 and was also illustrated by the regular grouping of spheres of 

 different sorts. That paper was characterised as "an interesting 

 and ingenious memoir " by the late Prof. Sohncke, who ex- 

 pressed the hope that his own criticisms (p. 383) would induce 

 the author " to establish his theory in a more solid and more 

 general way." Since that date Mr. Barlow has published 

 several investigations on the subject, and the present memoir, 

 which appears in the scientific Procee/iings of the Royal Dublin 

 Society, is an extended study of the close-packing of spheres of 

 different sizes. In the arrangement and re-arrangement of such 

 stacks he ingeniously traces a number of interesting analogies 

 which lead him far beyond the features of mere crystalline 

 growth and structure into chemical combination and decom- 

 position, solution, diffusion, and the phenomena classed under 

 stereo-chemistry. 



Mr. Barlow himself regards the close packing of spheres as 

 representing the position of equilibrium of mutually repellent 

 particles, and this he believes to be the key to all the problems 

 considered ; but the reader must be referred to the original 

 memoir for the details. 



The study of crystalline structure as represented by the close 

 packing of spheres or other figures is now being prosecuted by 

 several investigators in very different ways, and with very 

 different interpretations. The geometry of the subject is, of 

 course, independent of all the speculations which gather round 

 it, and deserves the very serious attention of chemists and 

 physicists. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



Cambridge. — Mr. Oldham, the University Lecturer in 

 Geography, announces a public lecture on the North-west 

 Frontier of India. Sir George Robertson, K.C.S.I., of Chitral 

 fame, will take the chair. 



The late Mr. Frank Chance has bequeathed 400 volumes to 

 the University Library. 



The Museums Syndicate report that owing to the increase 

 of the number of buildings under their charge, and the greater 

 requirements for research and other students, the sum placed 

 at their disposal for the annual maintenance of the scientific 

 departments must be augmented by 300/. 



1 " Das Problem der Krystallisation." By A. Turner. Pp. 98 ; 26 

 plates. (Leipzig : 1897.) 



"A Mechanical Cause of Homogeneity of Structure and Symmetry 

 geometrically investigated ; with special application to Crystals and to 

 Chemical Combination." By W. Barlow. Pp. 164. (Dublin : 1897.) 



A proposal is made by the Local Lectures Syndicate for the 

 granting of a diploma in Arts to University Extension students 

 who have passed through a prescribed course of study and 

 examinations. 



Dr. Gottlieb, assistant professor of pharmacology in the 

 University of Heidelberg, has been provisionally appointed suc- 

 cessor to the late Prof. Dr. W. von Schroeder. 



Mr. A. E. Briscoe has been appointed Principal of the new 

 technical institute in course of erection at Stratford. Mr. Briscoe 

 is at present head of the Physics and Electrical Department of 

 the Battersea Polytechnic. 



Referring to the London University Commission Bill, 1898, 

 which was introduced into the House of Lords by the Lord 

 President of the Council on February 21, and read a first time, 

 the British Medical Journal points out that it differs from the 

 Bill of 1897 in the omission of the names of the Commissioners. 

 From the schedule appended to the Bill it appears that the con- 

 stitution of the Senate is modified by giving to the Council of the 

 City and Guilds of London Institute one member, and by re- 

 ducing the number of Crown nominees from five to four. The 

 number of members of the Senate is thus retained at the same 

 figure, fifty-five, or with the Chancellor, fifty six. In the para- 

 graph dealing with Faculties, the sub-section recognising 

 examiners appointed by the University as members of the 

 Faculties has been omitted. The instructions to the Com- 

 missioners as to examinations are practically the same, and the 

 Senate will be required to hold separate examinations for internal 

 and external students unless it otherwise determine, " either 

 generally by regulation, or as to a particular subject by order." 

 But there is this rather important addition, that the Senate will 

 be required to communicate any such regulation to Convocation. 

 Part II. of the Schedule is now headed, " Matters for which pro- 

 vision must be made." These include the adequate protection 

 of all classes of students whether external or internal, collegiate 

 or non-collegiate, the recognition of teachers of the University, 

 and the regulations for the admission of internal students. The 

 sub-clause dealing with this last point has been modified, and as 

 it nows reads persons to be recognised as internal students will 

 be " students who have matriculated at the University, and are 

 pursuing a course of study approved by the University under one 

 or more of the recognised teachers of the University." 



The official report of the Proceedings of the recent annual 

 general meeting of the Association of Technical Institutions, 

 containing the address delivered by the President, the Right 

 Hon. Sir Bernhard Samuelson, Bart., F.R.S., has been issued. 

 In the course of his remarks the President pointed out that 

 much good will arise from the concordance between the various 

 educational agencies which has been arrived at in ten or twelve 

 county boroughs, one of the most conspicuous examples of 

 which is Manchester, where the School Board, the City autho- 

 rities with their splendid technical schools, and the Owens 

 College of the Victoria University are all acting in harmony, 

 and constructing the ladder so much talked of, but still so rarely 

 provided, on which a child can by intelligence and perseverance 

 mount from the humblest to the highest intellectual position. 

 As to the expenditure of the funds available for technical in- 

 struction. Sir Bernhard Samuelson presented the following ques- 

 tions to his audience : — Have we fully considered the relative 

 value of the various degrees of technical education ; would it 

 have been better for the nation if the 800,000/. per annum of 

 Customs and Excise Fund had been in the main devoted to the 

 higher rather than to the primary and secondary grades of 

 technical education ? Would not the lower grades even have 

 been better served if we had in the first instance made a deter- 

 mined effort to extend and improve general elementary and 

 secondary education ? Many educationists would answer these 

 questions in the affirmative. 



NO. 1479. VOL. 57] 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, February 3. — " Researches in Vortex 

 Motion. Part III. On Spiral or Gyrostatic Vortex Aggre- 

 gates," By W. M. Hicks, F.R.S. 



The chief part of the paper refers to a kind of gyrostatic 

 aggregate. The investigation has brought to light an entirely 

 new system of spiral vortices. 



