1 68 



NATURE 



[June i8, 1891 



with the sea- water, which was constantly renewed by the tide. 

 So rapid and complete is this process of interchange, that the 

 amount of river-water actually present diluting the water of the 

 Clyde sea area is much less than the amount which passes 

 through it every year, and is not equal to half of the average 

 rainfall. In an average year i '25 cubic miles of water, 97-5 per 

 cent, of which is pure sea-water, and 2*5 per cent, fresh- water, 

 enters the area at every tide ; and a slightly greater amount is 

 withdrawn, the whole being freshened a little so as to contain 

 2 7 per cent, of its volume of fresh-water. The great saltness 

 of the deep water of the sea lochs, on which their importance as 

 fishing-grounds depends, appears to be due to two causes. 

 One of these is the thorough mixture of the tidal water from 

 bottom to surface as it pours across the shallow bars at the 

 mouths of the lochs. The saltest surface water was always 

 found at flood-tide, off Otter Spit in Loch Fyne, where the salt 

 water welled up from beneath in consequence of the rapid 

 shoaling of the channel. Another cause of thorough mixture 

 is the influence of the wind, which seems to set up a complete 

 vertical circulation. Thus if wind is blowing strongly down 

 Loch Fyne, the freshened surface water is driven out of the 

 loch, and very salt water rises at the head of the loch to take its 

 place. In a down-loch wind the surface water is almost always 

 saltest at the head of the loch, and diminishes in salinity towards 

 the open sea. The paper concludes with a summary of the 

 chemical composition of the water, 



Paris, 

 Academy of Sciences, June 8.— M, Duchartre in the 

 chair. — On the currents which give rise to cyclones, by M. 

 H. Faye, The views held by Dr. Hann and Prof. Ferrel 

 concerning cyclones and anticyclones are compared. The 

 author believes that cyclones, but not anticyclones, are 

 dynamical phenomena, with which local circumstances of 

 temperature have nothing to do, and he shows that they 

 depend on the general movements of the atmosphere due to 

 Polar cold and equatorial heat. On this point, therefore, M, 

 Faye agrees with Ur, Hann.— Note on the presence of the 

 Kophobelemnon in the waters of Banyuls, by M. II. de Lacaze- 

 Duthiers. — The mastodon of Cherichira, by M, Albert Gaudry. 

 — A new chemical balance for rapid weighings, by M. Victor 

 Serrin. — Partial eclipse of the sun on June 6, observed at Nice, 

 by M. Perrotin. With a power of 280, the time of first contact 

 was observed to be 5h. 54m, 26s. ; and of second contact, 

 6h. 53m. 26s. Nice mean time. — Observations of the new aste- 

 roid discovered at Nice Observatory on May 16, by M. Charlois. 

 The observations are for May 16 and 25. — Observations of 

 Brooks's comet (1890 II.), made with the great equatorial 

 of Bordeaux Observatory, by MM. G, Rayet and L. 

 Picart. Twenty-three observations for position were made 

 between February 3 and April 29. The comet has been 

 followed from March 27, 1890, to April 29, 1891. — On 

 the theory of shooting-stars, by M. Callandreau. The author 

 develops the equation of condition to be fulfilled by radiant- 

 points belonging to the same family of meteors. According to 

 Mr. Denning's observations, the Perseid radiant-point moves 

 towards the east during the period of activity, a fact indicated 

 as probable by Leverrier in 1 871. This is in conformity with 

 the equation of condition, which shows that if the latitude of a 

 radiant-point varies slightly the longitude increases. — On two 

 systems of differential equations, of which the hyperelliptic 

 functions of the first order form the integrals, by M. F. Caspary. 

 —Determination of the mechanical equivalent of heat, by M. 

 Constantin Miculesco. The method adopted was similar in 

 principle to that used by Joule. Thirty-one experiments made 

 with this apparatus gave very accordant results, and the mean 

 of them all give 4267 as the mechanical equivalent of a calorie 

 in kilogram-metres.— Dielectric properties of mica at high tem- 

 peratures, by M. E. Bouty. The principal result of the research 

 is that the dielectric constant is almost invariable for rapid alterna- 

 tions. — Application of the principle of the transmission of pressures 

 to vvidely separated telephone transmitters, by M. P, Germain. — 

 Action of ammonia on some compounds formed with halogen 

 salts of mercury, by M. Raoul Varet, The author has studied 

 the action of ammonia on compounds formed with mercury 

 iodide and metallic cyanides, with the idea of determining the 

 rdle of certain compounds of ammonia in double decompositions, 

 — On a new method of preparing silicon chloro-iodides, by 

 _M. A. Besson. — On three cases of free development observed 

 in Bryozoas ectoproctse, by M. Henri Prouho,— On the locusts 



NO. I 129, VOL. 44] 



of Algeria, by M, Charles Brongniart. — On the morphological 

 nature of the phenomena of fecundation, by M. Leon Guignard. It 

 results from the observations that the phenomenon of fecundation 

 consists not only in the copulation of two nuclei of different sexual 

 origin, but also in the fusion of two protoplasms, also of differ- 

 ent origin, and represented essentially by the directing spheres 

 of the male and the female cell. — On the inclosures ofnephelinic 

 syenites found in the middle of phonolites from Hohgau and in 

 some other beds ; conclusions to be drawn from them, by M, A. 

 Lacroix, — Observations of the parallelism of Upper Cretaceous 

 strata of the Western Pyrenees (Lower Pyrenees and Landes), 

 by M. Jean Seunes. — The sympathetic nerve of accommodation 

 for the observation of distant objects, by MM. J. P. Moral and 

 Maurice Doyon. — Researches on the existence of parasitic 

 organisms in diseases of the crystalline lens of the eye of man, 

 and on the possible role of these organisms in the pathology of 

 certain ocular affections, by MM. Gallippe and L. Moreau. — 

 On the employment of carbon bisulphide dissolved in water for 

 the destruction of Phylloxera, by M. A. Rommier, 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



Glimpses of Nature : Dr. A. Wilson (Chatto). — Revelation of the Trinity : 

 S. B. G. McKinney (Stock). — Oysters and all about 1 hem, 2 vols. : J. R. 

 Philpots (Richardson). — Die Veranderlichkeit der Temperatur in Osterreich : 

 J. Hann (Wien).— Monograph of the British Cicadse, vol. ii. Part 6 : G. B. 

 Buckton (Macmillan).— A Guide-book to Books: edited by E. B. Sarganl 

 and B. Whishaw (Frowde).— Our Country's Flowers: W. J. Gordon (Day). 

 — Primo Resoconto dei Risullati della Inchiesta Oniitologica in Italia; 

 Parte Terza ed Ultima Notizie d'Indole Generale : E. H. Giglioli (Firenze). 

 — Chambers's Encyclopaedia, vol. vii, (Chambers). — Hand-book of the 

 London Geological Field Glass : H. G. Seeley (Philip).— Teaching in Three 

 Continents :W. C. Grasby (Cassell).— Bulletins de la Socie'te d'Anthropo- 

 logie de Paris, 4*^ fasc. (Paris, Masson). — Journal of the Chemical Society, 

 June (Gurney and Jackson).— Quarterly Journal of Microscopical Science, 

 vol. xxxii. Part 3 (Churchill). 



CONTENTS. PAGE 



Egyptian Irrigation 145 



Physiological Psychology. ByJ, S 145 



Achievements in Engineering. By N. J, L 147 



Geological Excursions. By T. G. B 149 



Our Book Shelf:— 



Meyer: " Across East African Glaciers " 149 



" Chemistry in Space " 150 



Letters to the Editor : — 



Erratic Track of a Barometric Depression. ( With a 



Chart.)— R^v. W, Clement Ley 150 



The Crowing of the Jungle Cock. — B. P. Cross . . 151 



Cordylophora lactistris. — Thomas Shepheard . . , 151 



Philosophical Instrument Makers. — A. Hilger ... 151 

 The Earthquake of June 7. — Prof. A. Riggenbach- 



Burckhardt 151 



Note on Egyptian Irrigation. By Sir Colin Scott 



Moncrieff, R.E., K.C.B 151 



The Second Ornithological Congress 153 



The Imperial Physical and Technical Institution at 



Berlin 154 



Crystallization. {^Illustrated.) By Prof. G. D. Liveing, 



F.R.S 156 



The Eruption of Vesuvius of June 7, 1891. By Dr. 



H. J. Johnston-Lavis 160 



Notes 161 



Our Astronomical Column : — 



Newly-discovered Markings on Saturn 164 



The Rotation Period of Venus 1(54 



A New Asteroid (310) 164 



The Royal Geographical Society 154 



Parka decipiens. By Sir Wm. Dawson, F.R.S, , , 165 



University and Educational Intelligence 165 



Scientific Serials 165 



Societies and Academies ... 165 



Books, Pamphlets, and Serials Received 168 



