00< 



NATURE 



[February 8, 1894 



magnet attached to the supporting frame. — On synthesised 

 borneols, by MM. G. Bouchardat and J. Lafont.— Thermal 

 constants of some polyatomic bases, by MM. Albert Colson 

 and Georges Darzens. For ethylene-diamine the observed 

 values were : — Specific heat 0-84 between 12° and 45° ; heat of 

 solution +7-6 cal. for i mol. in 4 litres of water at 15° ; heat 

 of neutralisation +23-54 cal. (i mol. normal salt in 5 litres of 

 water) ; heat of solution of the normal chloride -7 "55 cal. for 

 I mol. in 4 litres of water. For quinine, observations gave : — 

 rieat of solution for i mol. of Q.S04Ho.6n20 dissolved in 12 

 litres of water coriaining i mol. HoS04=-6"7 cal.; heat 

 of neutralisation +15 -5 cal. for freshly precipitated quinine. — 

 On the adaptation of the alcoholic ferment to the conditions of 

 living in media containing hydrofluoric acid, by M. E. Sorel. 

 The lac'.ic acid ferment is destroyed by the addition to the mash 

 of a small quantity of hydrofluoric acid, and the yield of alcohol 

 correspondingly increased. ?By cultivation in presence of 

 increasing quantities of hydrofluoric acid the resisting properties 

 of the alcoholic ferment may be considerably increased. — On 

 the relation of the palisade tissue of leaves to transpiration, by 

 M. Pierre Lesage. The palisade tissue appears to function as 

 a means of protecting the leaves from excessive transpiration. 

 — Main lines indicating directions of folds and contortions in 

 the geology of France, by M. Marcel Bertrand. — On the com- 

 position of some calcareous marls, by M. H. le Chatelier. — On 

 the forms of platinum in its bed rock, from the Ural district, by 

 M. A. Inostranzeff. — On the age of the human skeleton dis- 

 covered in the eruptive formation of Gravenoire (Puy-de-D6me), 

 by MM. Paul Girod and Paul Gautier. 



Berlin. 



Physical Society, Dec. 15, 1893.- Prof, du Bois Reymond, 

 President, in the chair.— Dr. A. du Bois Reymond spoke on 

 Lilienthal's experiments on flying. As a starting-point he had 

 chosen the study of the flight of birds, which may be divided 

 into three distinct kinds— flapping, steering, and soaring. Of 

 these the one demanding least expenditure of energy is soaring, 

 and investigation showed that under certain conditions flight is 

 possible if the wind possesses a vertical component. Experi- 

 ments showed that surfaces can acquire a horizontal motion by 

 the action of the wind only, when their curvature bears a certain 

 relation to their superficies, and that this relation corresponds 

 exactly to that which is observed in the wings of birds. Dr. 

 Lilienthal's flying machine consists of a correctly curved surface 

 whose area is 14 square metres, made by stretching linen over a 

 light wooden frame, and having a weight of about 20 kilos. In 

 its centre is an aperture for the experimenter's body, and the 

 apparatus is held in position by the person's arms. On running 

 rapidly down a gentle slope of a hill against the wind, the latter 

 soon acquires a vertical component, which then carries the flying 

 apparatus and propels it in a direction against the wind. The 

 speaker had seen Dr. Lilienthal sail over a space of about 120 

 metres, at an altitude of some 30 metres, in a minute ; with a 

 favourable wind it was possible to cover some 200 to 500 metres, 

 and Dr. du Bois Reymond had himself taken leaps through the 

 air of 20 to 30 metres under similar conditions. He was of 

 opinion that by practice far better results may be obtained as 

 regards soaring, and that then, by combining steering with soar- 

 ing, it will be possible to fly even when the wind is unfavourable. 

 It appears that the three essentials for the solution of 

 the problem of flight are (i) correct utilisation of the 

 wind ; (2) the correct shape of the supporting surfaces, 

 and (3) correct handling of the apparatus. — Herr Haensch 

 explained three different models of Nicol pri-ms, of which 

 Glans' showed itself to be best as regards construction and 

 efficiency. 



Januarys.— Prof. Kundt, President, in the chair.— Dr. Lum- 

 mer gave a detailed account of the experiments he had made, 

 before his journey to Chicago, on Siemen's and on Violle's unit 

 of light. Both of these must be rejected as standard-units in 

 cases where the platinum is melted in the blowpipe flame. 

 Experiments made to establish the Violle unit by means of an 

 electric current showed that in this case there were variations 

 of from 10 to 12 per cent., which made it unsuitable as an 

 absolute standard of light. Hefner's amylacetate lamp, which 

 the speaker had been examining during the last four years, 

 gives a unit which varies only by some 3 or 4 per cent, as long 

 as the necessary conditions are strictly observed and allowance 

 is made for varying meteorological conditions which aff'ect the 



lamp. It appears, therefore, that a really reliable unit of light 

 has still to be found. 



January 19. — Prof. Kundt, President, in the chair. — Prof. 

 Hale, of Chicago, exhibited and explained his lantern-slides of 

 solar photographs. — Prof. Neesen communicated on behalf of 

 Herr van Aubel, of Brussels, the latter's method of silvering 

 aluminium. It consists in cleaning the plate of aluminium 

 with benzol, then dipping it into a solution of sulphate of 

 copper until a thin film of copper is formed on its surface. At 

 this stage a layer of silver is deposited alectrolytically on the 

 plate. Prof. Neesen had found that the layer of silver thus 

 formed does not adhere very firmly to the aluminium. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



Books.— A Students' Text-Book of Botany : Dr. S. H. Vines, first half 

 (Sonnenschein). — Johnston's Elements of Agricultural Chemi'^try, revised by 

 C. M. Aikman, 17th edition (Blackwood). —Optical Kxperiments, revised 

 and arranged after the directions of Dr. H. Zwick (Newmann). — The fn- 

 ventioQS. Researches, and Writings of Nikola 'lesla : T. C. Martin (New 

 York, Electrical Engineer Office) — Electricity in the Service of Man : Dr. 

 R. Wormell, revised and enlarged by Dr. R. M. Walmsley (Cassell). — A 

 Textbook of Euclid's Elements : H. S. Hall and F. H. Stevens, Books 

 2 and 3 (MacmiUan). — Pain. Pleasure, and /Esthetics: H. R. Mar- 

 shall (Macmillan) — Primer of Philrsophy : Dr. P. Cams (Chicago, 

 Open Court Publishing Co.). — The Religion of Science : Dr. P. Carus, extra 

 edition (Chicago, Open Court Publishing Co.). — Investigations on Micro- 

 scopic F rms and on Protoplasm : Prof. O. Biitschli, translated by E. A. 

 Minchin (Black). — C'mgres Internationaux d'Anthropologieet d'Arch^ologie 

 prehistorique et de Zoolugie a Moscou. Mat^riaux, Deux Partie (Moscou). 

 Two Great Scotsmen the Brothers William and John Hunter: Dr. G. R. 

 Mather (Glasgow, J. Maclehose). 



Pamphlets. — Report of J. P. Lang'ey, Secretary of the Smithsonian In- 

 stitution, for the year ending June 30 1893 (Washington). — Seventh Annual 

 Report of the Liverpool Marine Bi' .logic li Committee and ..their Biological 

 Station at Port Erin : Prof. Herdman (Liverpool, D)bb). — IJber ein Inter- 

 ferenzrefractometer : L. Mach (Wien). — Physical Constants of Thallium : 

 W. H. Steele (Melbourne). — A New Thermoelectric Phenomen n: W. H. 

 Steele (Melbourne) — On the C mductivity of a Solution of Copper Sulphate : 

 W. H. Steele (Melb urne). — Sulle Perturbazioni Magnetiche dell' Agosto 

 1893, &c. : Dr. L Palazzo (Roma). 



Serials. — Bulletin de I'Academie Royale des Sciences de Belgique, 

 63*^ Ann6e, No. 12 (Bruxelles). — Dictionary of Political Economy, sixth 

 part (Macmillan). Naiural Science, February (Macmillan). — Botanical 

 (.iazette. January (Madison, Wis ). Proceedings of the So. iety for Psychical 

 Research. January (K. Paul). — L' Anthropologic, Tome iv. No. 5 (Paris, 

 Masson). — Geological Magazine, February (K. Paul). — Quarterly Journal of 

 the Geological Society, Vol. 1. part i. No. 197 (Longmans) — Bulletin of the 

 New York Mathematical Society. January (New York, Macmillan). — 

 American Naturalist, January 'Philadelphia). 



CONTENTS. PAGE 



A Critic Criticised. By Dr. Alfred R. Wallace, 



F.R.S 333 



Dynamos and Transformers. By P. A. M 337 



Golf. By W. Rutherford 338 



Our Book Shelf — 



Webb: "Celestial Objects for Common Telescopes " 339 



Loney : " Plane Trigonometry " 339 



Letters to the Editor :- 



Music, Rhythm, and Muscle.— Prof. T. Clifford 



Allbutt, M.D .340 



The Cloudy Condensation of Steam.— John Aitken, 



F.R.S. . . . 340 



The Os Pedis in Ungulates.— Prof A. E. Mettam 341 

 A Brilliant Meteor. — Dr. M. F. O'Reilly . . .341 

 The Vatican Observatory. {Illustrated.) By R. A. 



Gregory 341 



Notes 345 



Our Astronomical Column : — 



Eclipse Meteorology 349 



A Remarkable Cometary Collision 349 



Mira Ceti 349 



Proper Motions of Stars 349 



The System of Algol 349 



The Institution of Mechanical Engineers . . . 350 



On the Motion of Bubbles in Tubes . . . . 351 



Science in the Magazines . 35^ 



University and Educational Intelligent.- 352 



Societies and Academies. {Illustrated.) . . . 353 



Books, Pamphlets, and Serials Received 356 



NO. 1267, VOL. 49J 



I 



