584 



NATURE 



[October 9, 1890 



short sketch of the extension of the theory to groups of opera- 

 tions in general. The second part deals with Galois's theory of 

 algebraic equations, in particular their solution by radicals. The 

 material is taken from Jordan, " Traite des Substitutions"; 

 Serret, " Cours d'Algebre Superieure " ; and Netto, " Substi- 

 tutionen-Theorie." Other authors have been consulted, and the 

 whole has been strongly influenced by a course of lectures on 

 the subject by Prof. Klein. The editor of the Journal expresses 

 a belief that this development will prove extremely useful to 

 students. — This being the opening number of a new volume, is 

 graced by a fine portrait of Prof. Cayley, which gives a very 

 truthful presentment of this eminent mathematician's charac- 

 teristic features. 



In the numbers of the Journal of Botany for August and 

 September is an interesting mycological contribution from Dr. 

 A. Barclay, describing some of the Ustilaginese and Uredineae 

 parasitic on cereal crops and other crops in India. The most 

 important of these are the following : Puccinia Sorghi on 

 Sorghum vulgare, Melampsora Lini on Linum usitatissimum, 

 Uromyces Pisi on Cicer arietinuvi and on Lathyrus sativus, 

 Puccinia Fagopyri on Fagopyrum esculentum. Mr. W. H. 

 Beeby contributes a paper on the British species of Sparganium ; 

 as regards fertilization, he states that they are rarely visited by 

 insects ; they are all proterogynous, and mostly wind-fertilized. 

 Among the "Short Notes" is the very interesting record of 

 the occurrence of the very rare Ranunculus ophioglossifolius in 

 Gloucestershire. 



SOCIETIES AND ACADEMIES. 



Paris. 



Academy of Sciences, September 29. — M. Duchartre in 

 the chair. — On the theory of infectious disease, of re- 

 •covery, of vaccination, and of natural immunity, by M. Ch. 

 Bouchard. — On the absorption of carbon monoxide by rocks, 

 by M. Berthelot. Observations in mines after explosions have 

 been said to indicate that the rocks of which the walls are con- 

 stituted possess a specific property by virtue of which they 

 retain carbon monoxide in their pores for a longer period than 

 other gases. From some experiments made to investigate this 

 question, M. Berthelot finds that the volume of carbon monoxide 

 absorbed by argillaceous rocks and given up by them, is sen- 

 sibly identical with the volume of air absorbed and given up 

 under the same conditions. Hence, rocks impregnated with 

 carbon monoxide owing to an explosion do not retain it because of 

 any specific action peculiar to this gas. — On acetylene condensed 

 by the silent discharge, by the same author. An examination 

 of the result of the condensation of acetylene by means of the 

 silent discharge appears to indicate that it differs in character 

 from that obtained by the influence of heat on the same com- 

 pound. — Spark spectrum of gadolinium, by M. Lecoq de Bois- 

 baudran. The author gives the wave-lengths of the lines, bands, 

 and flutings characteristic of the spectrum of gadolinium. — On 

 the atomic weight of terbium metals, by the same author. The 

 value found from two experiments was 159 "48. — On a new safety- 

 lamp for use in mines, by M. Charles Pollak. The lamp is an in- 

 candescent one. It weighs about 1800 grammes, and will give 

 a light equal to 07 or o'8 of a candle-power for twelve hours. — 

 Observations of Comets Coggia and Denning (b and c 1890), 

 made with the great equatorial of Bordeaux Observatory, by 

 MM. G. Rayet, L. Picart, and Courty. Observations for posi- 

 tion were made on July 27 and 29 and on August 6 in the case 

 of the former comet, and on September 14 and 15 in the case of 

 the latter. — Thermo-electric researches, by MM. Chassagny and 

 H. Abraham. The authors find, from some experiments, that the 

 variation in the electromotive force produced by heating the 

 poles of a copper-iron couple is practically constant between 0° 

 and 100° C. It is therefore possible that thermo-electric ele- 

 ments may serve as standards of electromotive force better than 

 electro-chemical cells. The same results were found with 

 couples two months old as with those only two days old. — On a 

 fungus of the Mucedinean group, by M. Raphael Blanchard. — 

 On the properties of the principal natural colouring-matters of 

 yellow silk, and their similarity to those of carrotin, by M. 

 Raphael Dubois. Evidence is adduced to show that raw yellow 

 silk owes its colour to the presence of a substance analogous to 



NO. 1093, VOL. 42] 



the colouring-matter recently extracted from Xh^Diaptomns dmtt- 

 cornis, by M. Blanchard, and considered as a carrotin of animal 

 origin. — The identity in the structure of lightning and discharges 

 from an induction machine, by M. E, L. Trouvelot. 



Stockholm. 



Royal Academy of Sciences, September 17.— On the 

 discovery of cerium minerals and columbite, and on the occur- 

 rence of microlite, by Baron Nordenskiold.— On the discovery 

 of pinakiolite, trimerite, and centrolite, by G. Flink, com- 

 municated by Prof. Brogger. — On inclosures of dissimilar rocks 

 in some Scandinavian diabases, by Herr H. Backstrbm. — On 

 maxima and minima by double integrals, by Dr. O. Kobb. — On 

 a generalization of the Bemoullian functions, and their connection 

 with the generalized series of Riemann, by Dr. A. Jonquiere, of 

 Basel. — Some formulae of Bierens de Haan, by Dr. Lindman. 

 — ifetudes de la distribution spectrale de I'absorption dans le 

 spectre infra-rouge, by Dr. K. Angstrom. — On phenyl- totyl 

 and benzylen-diamin, by Dr. Soderbaum and Prof. Widman. — 

 Derivatives of ortho-amido-benzyl-alcohol, iii., by Dr. Soderbaum. 

 — Researches on the conductibility of the caloric in porous 

 humid bodies, by Herr S. A. Andree, C.E. — On the new 

 edition of the collected works of Galileo, by Dr. G. Enestrom. 



Amsterdam. 



Royal Academy of Sciences, September 27. — Prof, van 

 de Sande Bakhuysen in the chair. — Prof. Schoute dealt with 

 some general theorems relating to directly similar plane figures. 

 — Prof. Hubrecht described phases in the early development of 

 the shrew's placenta, and called attention to the fact that, 

 whereas in the hedgehog the uterine epithelium disappears — the 

 subepithelial stroma forming the maternal contribution to the 

 placenta — in the shrew, on the contrary, this contribution is 

 directly derived from the epithelium of the uterus. 



CONTENTS. PAGE 



A New Theory for the Sensitive Plant. By F. W. O. 561 



Christy's " Birds of Essex " 564 



Hypnotism. By Dr. A. T. Myers 565 



Oijr Book Shelf:— 



Wright: " Text-book of Mechanics." — W 567 



Stewart: "An Elementary Text-book of Heat and 



Light."— W 567 



" The Confessions of a Poacher " 567 



Ward: "Examination Papers in Trigonometry." . . 567 



" Blackie's Modern Cyclopaedia. " 567 



Letters to the Editor : — 



Recent Classification of the Shrews. — Dr. R. W. 



Shufeldt 567 



Musical Sands. — Cecil Carus- Wilson 568 



With what Four Weights (and a Pair of Scales) can 

 be Weighed any Number of Pounds from I to 40 



inclusive ?—E. Ri F 568 



Protective Coloration of Eggs.— E. B. Titchener . . 568 

 Lunar Photography. {Illustrated.) Richard A. 



Gregory 568 



Comparative Palatability of Insects, &c. By E. B. 



Titchener and F. Finn , 571 



The Progress of Biology in Canada 572 



Notes 573 



Our Astronomical Column : — 



Objects for the Spectroscope. — A. Fowler 576 



Observations of Comets 576 



Photographing Stars in the Daytime 576 



Physics at the British Association 576 



Biology at the British Association 579 



Geography at the British Association 579 



Anthropology at the British Association 580 



The Volcanoes of the Table-land of Mexico . . . 582 

 A New Electric Light Otto Gas-Engine. {Illus- 

 trated.) 583 



Scientific Serials 583 



Societies and Academies 584 



