94 



NA TURE 



{May 22, 1884 



the northern coast of the Gulf of Finland, seven miles distant 

 from the sea-shore) is explained by the increase of the rate of up- 

 heaval of the c >uiitry towards the north. This old lake, like Lake 

 Ladoga of our days, seems to have had but a poor fauna. Many 

 smaller lakes which covered Esthonia, had a peculiar freshwater 

 fauna Gravel and sand, with Ancyltis fluviatilis, like that found 

 in Lake Bayl.al, and Lymnccus ovatus, as also Neritina fluviatilis, 

 Paludina impura, Unio, and Cyclas are found at heights varying 

 from 50 to 150 feet above the actual sea-level. On tE^el these 

 deposits are widely spread, and descend to a level of 20 feet 

 above the sea. At a still later period the lakes were filled with 

 ooze, which constitutes now the so-called '"marl of prairies" 

 ( Wiesenmcrgel) filled up with Planorbis, Lymnaus, &c, and 

 containing also remains of man, together with bones of reindeer, 

 as described by Prof. Grewingk. 



In connection with this subject reference may be made to the 

 conclusi ins arrived at as to the glacial formations by M. 

 Nikitin, while making the geological survey within the limits of 

 sheet 58 of the geological map of Russia, comprising Yaroslav 

 and the eastern parts of Novgorod and Tver. Tbe features of 

 the Till, or Boulder-clay, which covers this region, are so much 

 at variance »ith the theory of floating ice, which has been pro- 

 posed to explain them, as well as with every other aqueous 

 the iry, a id so much in conformity with the idea of a bottom 

 moraine, that M. Nikitin has been compelled to admit the 

 former extension of the northern ice-sheet of the Glacial period 

 through mt the region of the Upper Volga (vol. ii. fa-c. 3). 

 The B ulder-clay of the Government of Poltava, sometimes 

 20 m thick, consists of triturated, unstratified material-, partly 

 derived tr mi sources within the region itself, and partly brought 

 from the north. It contains scratched boulders, and though un- 

 doubtedly of glacial origin, its precise mode of formation still 

 remains in dispute, notwithstanding the careful attention given 

 to the study of the question by M. Armashevsky (vol. ii. 

 fasc. 6). 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE 



Cambridge. — The Natural Sciences Tripos, Part [., com- 

 menced on May 17 ; Part II. will commence on May 29. 



The examiners in the Mathematical Tripos of 1S83-84 have 

 reported that the work done in Part II. was on the whole disap- 

 pointing, and inferior to that usually done in the old "five-days" 

 examination. They suggest that this may be due to its taking 

 place in the Easter Term, in which revision of subjects is usually 

 much interrupted. In Pan III. eleven candidates presented 

 themselves, of whom seven were placed in the first division. 

 The work was extremely good, the candidates having judiciously 

 specialised their reading. 



SCIENTIFIC SERIALS 



Bulletin a'e V Academic Royale de Belgique, February 2. — On 

 the crepuscular phenomena of the months of November and 

 December 1883, by F. Terby. — On the physiological action 

 of aspidospermine (bark of A^pidosperma quebracho), by Dr. 

 Closson. — Remarks on some Sanskrit verbal roots of the eighth 

 class, by J. van den Gheyn. — Contributions to the biography of 

 the portrait painter A. de Vries, and of the Flemish painter 

 Theo lore van Loon, by Auguste Castan. — Biographical notice 

 of th' Dutch painter Marin van Romerswael, by Henry 

 Hyma is. 



Mar h I. — Note on the Pons-Brooks comet 1812, observed at 

 Louvain during the winter of 1883-84, by F. Terby, and at 

 Brussels by L. Niesten. — On an empirical relation between the 

 coefficient of internal friction of liquids, and its variations under 

 changes of temperature, by P. de Heen. — Preliminary commu- 

 nication on the anatomy of the Acarians, a group of Arachnidaj, 

 by J. MacLeod. — On the changes of refrangibility in the elec- 

 trical spectra of hydrogen and magnesium, by Ch. Fievez. 



Journal of the Russian Chemical and Physical Society, 

 vol. xvi. fasc. I. — The dilatation of liquids, by D. Mendeleeff. 

 — On the tension of vapour of solutions, by D. Konovaloff. 

 The author has resorted in his measurements to a method 

 much like that of Magnus, and gives the results of his mea- 

 surements (illustrated by curves) for mixtures of water with 

 alcohols and acids : formic, acetic, propionic, and butyric ; they 



are followed by a discussion on the distillation of solutions, on 

 mixtures, and on the solubility of liquids. — On an acoustic instru- 

 ment for measuring the number of vibrations, by A. lzraileff. — 

 New demonstrations of the conditions of minimum of devia- 

 tion of a ray by the prism, by K. Kraevitch. In most 

 treatises on physics this demonstration is made by means of 

 methods more or less artificial, excepting the treatise of Jamin. 

 who has resorted to differential calculus. However long, M. 

 Kracvitch's demonstration is very simple, and is deduced very 

 naturally out of the fundamental laws of refraction. — On the 

 friction of well lubricated bodies, by N. Petroff. 



SOCIETIES AND ACADEMIES 

 London 



Royal Society, May 8. — " On a Relation between the Co- 

 efficient of the Thomson Effect and certain other Physical 

 Properties of Metals." By Shelford Bidwell, M.A., LL.B. 



Having observed that the coefficient of the Thomson effect is 

 generally positive in those metals which have a great specific- 

 resistance and specific heat, and negative in those which arc dis- 

 tinguished by a great coefficient of expansion, the author endea- 

 voured In find an empirical formula expressing the coefficient of 

 the Thomson effect in terms of the specific resistance, specific 

 heat, and coefficient of expansion. Though he was not alto- 

 gether successful, he believes that the subjoined table points to 3 

 close relation between them. 



I. II. III. IV. 



The first column contains tire names of the metals, except 

 alloys, given in Tait's thermo-electric diagram [Trans. R.S.E., 

 vol. x.xvii. p. 125). The second column gives the coefficients of 

 the Thomson effect: these are taken from Everett's table ("Units 

 and Physical Constants," p. 151), which is based upon Tait's 

 diagram. 



H, R, and E being numbers proportional to the specific heats. 

 specific resistances, and coefficients of expansion of the various 

 metals. IIxR-E 2 gives the numbers in the third column of 

 the table. H = specific heat x IO 3 , R = specific resistance x IO 3 . 

 Ii = coefficient of expansion x io 8 -f- 34. The multipliers IO 3 and 

 IO 8 were used merely for the convenience of getting rid of deci- 

 mals ; the divisor, 34, was so chosen that while the ratio of the 

 first number to the last in Column III. should be as nearly as 

 possible equal to the ratio of the first number to the last in 

 Column II., the number corresponding to lead in Column III. 

 should at the same time be as near zero as possible. Both con- 

 ditions could not be exactly fulfilled at once. The authorities 

 for the specific heats, specific resistances, and coefficients of ex- 

 pansion are given in the paper. 



Column IV. gives the numbers in Column III. divided by 

 2400, to facilitate comparison with Column I. 



It will be seen that with one exception the order o f magnitude 

 of the numbers in Column IV. is exactly the same as the order of 

 those in Column II. The rate of decrease is not, however, the 

 same, the numbers diminishing too rapidly in the upper half of 

 Column IV., and too slowly in the lower half. 1 



1 With rcg.-ird to aluminium it is suggested that Matthiessen's determina- 

 tion of the specific resistance, o'o2Q, is possibly too high. Moreover the 

 author found experimentally that the Thomson coefficient of the specimen of 

 aluminium which he used was slightly + instead of-, as given in Column II.; 

 it is also shown as -f- in the diagram at p. 178 of Jenkin's " Electricity." If 

 its specific resistance were as highaso'026, it would come between magnesium 

 and lead in Column IV. 



