3;,6 



NA rURE 



[Feb. 3, 1887 



Prof. Domenico Lovisato, of the Cagliari University, is reniarli- 

 able for its richness in aluminium, and the highly oxidised state 

 of the iron contained in it. Outwardly it strongly resembles 

 zoisite, although its crystalline system and optical properties 

 leave no doubt as to its true character. — On some peculiarities 

 in the organisation of the .Schizoneniertians, by M. Remy Saint- 

 Loup. The exact disposition of the cephalic fossettes is here 

 determined by a comparative study of three types of these 

 organisms. — On the colonial vascular system of the Tunicata, 

 by iVI. F. Lahille. A careful study of this system leads the author 

 to the conclusion that there is no valid reason for separating 

 the Monascidians and Synacidians into two distinct orders of 

 Tunicata. — On the cranial nerves of a human embryo thirty- 

 two days old, by M. C. Phisalix. Balfour's theory, based on 

 negative grounds, that the cranial nerves are disposed on a type 

 absolutely diiferent from the spinal nerves, seems disproved by 

 the anatomical study of this subject. — Researches on the physio- 

 logical action of methylal, by MM. A. Mairet and Combemale. 

 These researches show that, in whatever way introduced into 

 the system, methylal always produces the same hypnotic effects, 

 but more rapidly by hypodermic than by pulmonary injection. — 

 On the existence of submerged valleys in the Gulf of Genoa, by 

 M. A. Issel. From the recent hydrographic surveys of Capt. 

 J. B. Magnaghi, it appears that the valleys of the Bisagno, 

 Polcevera, Quiliano, and other Ligurian streams are continued 

 seawards by submarine v.illeys, which retain the same fluvial 

 direction, and are perfectly distinct to a depth of at least 900 

 metres. — On the Artesian wells and new oases created in the 

 Wed Rir', .South Algeria, by M. G. Rolland. Since 1S59, the 

 French have sunk 117 wells in this region, creating five new 

 oases, and increasing fivefold the value of the land. In the 

 same period the population has been doubled, and many 

 thousands of dale-palms planted. 



Berlin 



Physical Society, December 3, 1886.— Prof, von Helm- 

 holtz in the chair.— Dr. Konig exhibited a von Kries colour- 

 mixing apparatus, the third specimen of the kind hitherto 

 turned out in the factory of Schmidt and Hansch, and discussed 

 in a searching manner the construction of this instrument. The 

 instrument contained essentially two disploceable slits, the light 

 of which was by a prism decomposed into two spectra falling on 

 each other and producing the mixture of the colours. A second 

 double slit, and a simple fifth slit allowed a comparison of the 



mixed colours and an admixture at pleasure of white light. Dr. 



Weinstein reported on his deductions from observations of tlie 

 earth's current in the telegraph lines of the German Empire. 

 .\mong the results already elsewhere published of his calculations 

 (vide Nature, vol. xxxiii. p. 624) it may here be brought out that, 

 apart from its disturbances, the earth's current showed a daily 

 peiiod with eight fluctuations, which, however, did not occur 

 throughout the whole year, nor always in a similardirection. These 

 fluctuations were least in the morning between five and seven 

 o'clock. They were the cause that the statements respecting 

 the daily maxima .and minima differed so considerably among 

 the different authors. The earth's current showed an intimate 

 relation to the earth's magnetism, and especially to the de- 

 clination. The speaker failed, however, to discover a relation 

 in the earth's current to the period of the sun's rotation, although 

 such a relation was asserted for the earth's magnetism. The 

 latter, too, was a point which the speaker doubted, and that 

 because he had been unable to confirm the relation, which w.is 

 likewise affirmed, between the aurora and the sun's rotation. 

 It was true he obtained an average period of about twenty-five 

 days, but the minima amounted to twelve and the maxima to 

 thirty-seven days, and between such extremes a mean was not 

 allowable. For the earth's current likewise he found minima of 

 twelve days and maxima of thirty-seven days, and this result ap- 

 peared to him to conflict with the assumption of a connection 

 between the earth's current and the sun's rotation. He con- 

 jectured that in the case of the earth's magnetism single values 

 deviating too strongly from one another had been united into a 

 mean. Be it further related that the intensity of the earth- 

 current proved itself to be nearly proportional to the length of 

 the lines. In the discussion following this address, Dr. Brix 

 spoke of the earth plates which had been introduced in the lines 

 used for measurements of the earth-currents, and which had 

 hitherto proved so little disturbing that for the present the intro- 

 duction of unpolarisable plates was desisted from. 



Christiania 

 Society of Science, October IJ, 1886. — Herr Schoyen 

 announced that through experiments carried out during the 

 summer he had succeeded in demonstrating that the parasite 

 Tylcitchus hordci, described by him, which in the district of 

 Lom causes the remarkable disease on rye termed "krok," also 

 attacks Elymus arenarius, whereby his opinion that the parasite 

 was transmitted from the latter to the rye-fields has been con- 

 firmed. He further stated that he had received samples of rye 

 affected with the same disease from Heligoland ; here, too, it 

 extended along the coast in the proximity of Elymus arenarius. 



BOOKS AND PAMPHLETS RECEIVED 



Die Klimate der Erde, 2 vols. : Dr. U. Woeifog (ICostenoble. Jena).— 

 The Factors of Organic Evolution : H. Spencer (Williams and Norgate). — 

 Beiblatter zu den Annalen der Physik und CKemie, 1886, No. 12 (Bartti, 

 Leipzig). — The Electrician's Directory (Tucker).— Outlines of Classification 

 and Special Morphologyof Plants : Dr. K. Gould (Clarendon Press).— Travels 

 in the Wilds of Ecuador: A. Simson (Low). — Meteorological Observations 

 at Stations of the Second Order, for the Year 1882.- Hourly Readings, 1883, 

 part iv. — Resultate der Polarlicht Heobachtungen augestellt im Winter 1882 

 und 1883 : Dr. K. R. Koch (Asher, Berlin).— Gold Fields of Victoria ; Reports 

 of the Mining Registrars for Quarter ended September 30, i886(Ferres, Mel- 

 bourne). — Report on the Administration of the Meteorological Department of 

 the Government of India in 1885-86. — An Explanatory Arithmetic, 3rd edition : 



E. Spickernell (Griffin, Portsn 

 Differential Calculus, 6th edition ; 

 ^[otions. 5th edition: W. T. Lym 

 (Churchills).— Catalogue of Canadis 

 (Dawson, Montreal).— Archives Ita 



ith). — An Elementary Treatise 

 B. Williamson (Longmans).— Celestial 

 (Stanford). — Year-B ok of Pharmacy 

 ri Plants, part 3, Apetalae: J. Macoun 

 Lennes de Biologic, tome viii. fa=c. i 

 (Loescher).— Aluminium: J. W. Richards 1 Low).— Examples of Exercises 

 given in the National Philosophy Class of Glasgow University : M. Maclean 

 (.MacLehose, Glasgow). — Report on the Medusae collected by the U.S. Fish 

 Commission in 1883.S4: G. W. Fewkes C^Vashington).- The Blue Hill 

 Meteorological Observatory : A. L. Rotch (Boston). 



CONTENTS PAGE 



A History of the Theory of Elasticity. By A. G. 



Greenhill 313 



The Encyclopaedia Britannica 314 



A Treatise on Chemistry _ji6 



Our Book Shelf:— 



Holden : " Photography the Servant of Astronomy " 317 

 Rulot et Van den Broeck : " Observations nouvelles 

 sur le Tufeau de Ciply et sur le Cretacesupcrieur du 



Hainaut 317 



Letters to the Editor : — 



On Two Jade-handled Brushes.— Prof. J. P. O'Reilly 31S 

 The Cambridge Cholera Fungus. — Walter Gardi- 

 ner; George Massee 319 



Earthquakes. — Thomas W. Kingsmill 319 



The Calendar and General Directory of the Science 



and Art Department 320 



The Progress of Astronomical Photography . . . 321 

 Meteorological Conditions at the Time of the Erup- 

 tion of Mount Tarawera, New Zealand. By 



Capt. F. W. Hutton 322 



A Few of our Weather Terms. By Rev. W.Clement 



Ley j23 



Note on Instantaneous Shutters. By A. Mallock. 



{Illustrated) ^24 



On some Phenomena connected with the Freezing 

 of Aerated Water. By George Maw. {Illustrated) 325 



Notes 326 



Our Astronomical Column : — 



The New Algol-type Variable 329 



Gore's Variable near x' Orionis 329 



The Southern Comet ' 329 



A Short Method for Computing Refr.actions .... 329 



Comet Brooks (18S7 /') 330 



Astronomical Pnenomena for the Week 1887 



February 6-12 • 330 



Geographical Notes 330 



Physical Notes 331 



On the Morphology of Birds. lly Prof. W. K. 



Parker, F. R.S 331 



Scientific Serials T^y.^ 



Societies and Academies 334 



Books and Pamphlets Received 536 



