March 9, 1899] 



NA TURE 



45: 



clear as to the method of formation of lightning and auroral 

 discharges, the phosphorescent glow of the clouds, ball lightning, 

 and other every-day phenomena. Is a cloud to be considered as 

 one big conductor, or does it insulate and separate the electrified 

 masses on either side of it ? Are the great displays to be seen 

 on the summits of the Rocky Mountains due to the influence of 

 the atmosphere or to something going on in the earth beneath ? 

 Are large drops really made up by the agglomeration of small 

 cloud particles, or are both the drops and electricity formed 

 simultaneously by the sudden dissipation of unstable molecular 

 equilibrium that exists in supersaturated cloudy air (as suggested 

 by the editor in his article of iSgi in AgrUidlural Science on 

 the " Artificial Production of Rain ") ? Do the larger drops of 

 rain really possess a greater electrical density on their surfaces 

 than the small drops and particles, or do they not rather lose 

 their charges immediately either by evaporation or by gentle 

 discharge to the neighbouring drops ? These and other questions 

 crowd upon our thoughts ; but satisfactory replies can only be 

 given after physicists have invented appropriate methods of in- 

 vestigation. Meteorological observers may contribute to the 

 solution of the problems by collecting both general data and 

 special observations of exceptional phenomena, but the dis- 

 cussion of the data and the definitive decision by means of ex- 

 perimentation as to the merits of conflicting hypothetical 

 explanations must be left to the leading physicists of the world. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



CAMBRIDGE. — The election of a professor as member of the 

 Council of the Senate, to fill the place of Prof. Robinson, now 

 Canon of Westminster, will take place on Friday, March 17. 



Prof. Woodhead is appointed an Examiner in State Medicine, 

 in the place of the late Dr. Kanthack. 



Syndicates are to be appointed to obtain plans and estimates 

 for the new buildings of the Medical School and of the Botanical 

 Department. 



Mr. Frederick Treves, consulting surgeon to the London 

 Hospital, has been appointed an Emeritus professor of surgery 

 to the London Hospital, and will give a course of lectures in 

 clinical surgery in the winter session. The special subjects and 

 dates will be announced in due course. 



Prok. a. H. S.^vvce, of Oxford University, has been ap- 

 pointed Gififord Lecturer in Aberdeen University for 1900-1902. 

 The honorary degree of LL. D. has been conferred upon Mr. 

 Charles Stewart, F.R.S., Curator of the Museum of the Royal 

 College of Surgeons, England ; and Mr. George F. Stout, 

 Lecturer on Comparative Psychology in Aberdeen University. 



As will be seen from our advertisement columns a successor 

 to the late Prof. Rutherford in the chair of Physiology of the 

 University of Edinburgh will shortly be appointed. Applic- 

 ations for the post, accompanied by relative testimonials, should 

 reach the Secretary to the Curators, at 66, Frederick-street, 

 Edinburgh, on or before May 20. 



In connection with the inauguration of the new buildings 

 of the Middlesex Hospital Medical School, Dr. F. Hetley, a 

 former student, has contributed the sum of 1000/. to perpetuate 

 the Hetley Clinical Prize of 25/. per annum, founded in 1S84. 



A CH..ilR of Hygiene has been endowed in Harvard Uni- 

 versity by a donor whose name is withheld. 



The following appointments abroad are announced in 

 Science : — Dr. James Monroe Taylor to be president of Brown 

 University ; Dr. T. J. J. See to be professor of mathematics at 

 the Naval Academy, Annapolis ; Prof. Fritz Regel, of Jena, to 

 be professor of geography at Wlirzburg ; Dr. Erich v. Drygalski, 

 of Berlin, to be professor of geography at Tubingen. 



The resignation of Dr. Robert Otto, professor of chemistry 

 in the Institute of Technology at Braunschweig, is announced. 



SCIENTIFIC SERIALS. 

 Amciican Journal of Science, February. — Contact metamor- 

 phism, by J. M. Clements. The various Huronian sediments 

 which form a great portion of the iron-bearing districts of the 

 Upper Peninsula of Michigan have in all of these districts been 

 found to be penetrated by dikes of igneous rocks, which are 

 predominantly basic in character. The author describes the 

 products which have resulted from the intrusion of basic dikes 

 in the Mansfield slate formation. Between the dolerites and 



NO. 1532, VOL. 59] 



the slates there are masses of hard, peculiar hornstone-Iike rocks, 

 which have a well-banded character. Beginning with the clay- 

 slate, the least metamorphosed rock in the district, the series 

 passes through phyllites, spilosites, and desmosites to those 

 which are known as adinoles, the latter being those which 

 immediately adjoin the intrusive. — The origin of mammals, by 

 H. F. Osborne. The author traces the ancestry of mammals to 

 the Upper Permian, and in doing so he adopts Gill's two sub- 

 classes of mammals, namely the Eiilheria, comprising marsupials 

 and placentals, and the Prolotheria or monotremes. There are 

 grounds for the view that the Tlieriodontia are the Hypothe7-ia 

 or Promaminalia, because it appears that within the order may 

 well have existed some small insectivorous types, far less 

 specialised in both structures than either the carnivorous 

 Cynodonts or herbivorous Gomphodonts, as one of those 

 conservative species of adaptive radiation which form the focus of 

 a new progressive type. — Chemical composition of tourmaline, 

 by S. L. Penfield and H. W. Foote. The composition was 

 deduced from the results of an analysis of a few specimens 

 carried out with the utmost regard to accuracy. The specimens 

 selected were the colourless tourmaline from De Kalb, St. 

 Lawrence County, New ^'ork, and the pale green variety from 

 the felspar quarries at Haddam Neck on the Connecticut River. 

 The authors regard all varieties of tourmaline as salts of the 

 acid HsAl3(B. OHjoSijOi;!, in which the complex aluminium- 

 horosilicic acid radicle exerts a mass effect by virtue of which 

 the remaining hydrogens may be replaced by metals of 

 essentially different character without bringing about any 

 pronounced change of crystalline form. — The thermodynamic 

 relations for steam, by G. P. Starkweather. Discusses the 

 application of Van der Waals's equation of condition to steam 

 along the saturation line. — A volumetric method for the estima- 

 tion of boric acid, by L. C. Jones. This is based upon the 

 reaction 5KI + KIO3 + 6HC1 = 6K.C1 -f 3H.,0 -t- 3I.,. The 

 liberated iodine may be removed by sodium thiosulphate, and a 

 solution obtained which is absolutely neutral, containing only 

 neutral salts, potassium iodide, iodate, and tetrathionate. Boric 

 acid in moderate amount in solution has not the slightest action 

 on a mixture of iodide and iodate. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, February 16. — "The Thermal Deformation 

 of the Crystallised Normal Sulphates of Potassium, Rubidium, 

 and Citsium." By A. E. Tutton, B.Sc. Communicated by 

 Captain Abney, C.B., F.R.S. 



In this memoir are communicated the results of sixty-four 

 determinations of the thermal expansion of the orthorhombic 

 crystals of the normal sulphates of potassium, rubidium, and 

 cesium, carried out for the three axial directions of the crystals 

 with the aid of the compensated interference dilatometer 

 previously described by the author. 



The coefficients of cubical expansion exhibit a progression, 

 corresponding to the progression of the atomic weights of the 

 three respective metals. This is true of both the constants a and 

 b in the general expression for the coefficient of cubical expan- 

 sion, a = a -\- 2bt, for any temperature /. 



The order of progression of the two constants is inverted ; a, 

 the coefficient for 0°, diminishes with increasing atomic weight of 

 the metal, while i, half the increment of the coefficient per 

 degree of temperature, increases. Consequently, the co- 

 efficients of cubical expansion of the three salts converge, with 

 rise of temperature, and attain equality in pairs. Beyond the 

 temperature of identity divergence occurs, and an increase 

 of atomic weight is now accompanied by an increase of 

 expansion. 



The differences between the coefficients of linear expansion 

 along the three axial directions of any one salt, although only 

 amounting to one-eighth of the total coefficient, are large com- 

 pared with the differences between the values for the same 

 direction of the three salts. This, together with the fact that 

 the replacement of one metal by another is accompanied by 

 considerable modifications of the relations of two of the three 

 values for the original salt, those corresponding to the axes 

 a and c, prevent the coefficients of linear expansion for any 

 one direction of the three salts from exhibiting any progression 

 corresponding to that of the atomic weights of the three metals. 



The increment of the linear coefficient of expansion along the 

 axis c of each salt is about twice as large as the increments for 



