96 



NATURE 



[November 28, 1895 



is unfortunate for the simplicity of the argument of this paper 

 that the property of such a determinant as A, that after division 

 by its obvious factors F(p, i), F(p, — i), it leaves a perfect 

 square, is one which, as far as I know, direct algebraical methods 

 have not yet supplied." 'Y\\\% lacuna Mr. Taylor supplies. — Lieut. - 

 Colonel Cunningham, R.E., communicated a criterion of 2 as 

 a 16''^ residue, and added some remarks upon cercain of Mer- 

 senne's numbers. — The following papers were taken as read : 

 Notes on matrices, by Mr. J- Brill ; certain general series, by 

 Mr. F. H. Jackson ; note on the representation of a conic by a 

 linear equation, by Mr. J. Criffiths ; on the representation of a 

 number as a sum of two squares, by Prof.. G. B. Mathews ; re- 

 searches in the calculus of variations : part vii. , limiting conditions 

 in multiple integrals ; part viii. , reduction of the problem of the 

 discrimination of maxima and minima values in double integrals 

 with variable limits to a new problem in single integrals, by Mr. 

 E. P. Culverwell ; a note on certain forms of the equation of 

 normals to conic sections, by Mr. J. L. S. Hatton. 



Paris. 

 Academy of Sciences, November 18.— M. Marey in the 

 chair. — Truffles {Terfezia hanotaiixii) from Teheran, by M. Ad. 

 Chatin. The characteristics of Persian truffles and their spores 

 are described. The name Terfezia hanotauxii is given to these 

 truffles as forming a new species. The most important characters 

 are given for comparison of the other known species of Terfezia : 

 T. claveryi, T. boudieri, T. hajizi, and T. leonis. — On a prob- 

 ably new e'ement existing in the terbium earths, by M. Lecoq 

 de Boisbaudran, The evidence relied upon is that of an absorp- 

 tion band at A 4877, which the author fails to connect with 

 known elements. — A memoir, by M. A. Sarrat, on a demon- 

 stration of Fermat's theorem. Impossibility of the equation 

 ^n ^ i,n — ^n j^ whole numbers, was submitted to a committee. 

 — A note of M. J. Laborde on the causes of the form- 

 ation of hail was similarly disposed -of. — Observations of the 

 sun, made at Lyons Observatory (with the Brunner equatorial) 

 during the second quarter of 1895, by M. J. Guillaume. — On the 

 employment of punching and shearing as methods of testing 

 metals, by MM. L. Bacte and Ch. Fremont. A machine, 

 called by the authors an elasticiniMre, is described by means of 

 which indicator diagrams are obtained which show the actual 

 character of the instantaneous stresses developed in the oper- 

 ations of punching and shearing. Special test-samples are not 

 required, the machine is applied while the material is being 

 worked up in the ordinary way. — On a power dynamometer 

 specially applicable to physiological studies, by M. Charles Henry. 

 — On the origin of atmospheric oxygen, by M. T. L. Phipson. 

 The author recalls the results of his researches on this subject, 

 and summarises them as follows : ( i ) In the most distant geo- 

 logical periods nitrogen formed, as now, the principal part of the 

 earth's atmosphere. (2) The presence of free oxygen in this 

 atmosphere is entirely due to vegetation. Primitive plants were 

 the means by which oxygen was naturally supplied to the air. 

 (3) Plants now living are, like those of geological times, essen- 

 tially anaerobic. (4) As the quantity of free oxygen in the 

 atmosphere has gradually augmented, the aniierobic cell has 

 become modified into more or less aerobic forms (fungi, bacteria), 

 and finally has become completely aerobic (in animal life). (5) 

 The lowest unicellular algae give, weight for weight, much more 

 oxygen to the atmosphere than to the superior plants. (6) In 

 proportion with the slow increase of the relative quantity of 

 oxygen in the air, the cerebro-spinal nervous system, the highest 

 characteristic of animal life, has become more and more com- 

 plex. — Synthesis of methyleugenol. Constitution of eugenol, 

 by M. Ch. Moureu. Allyl veratrol is .synthetically formed and 

 shown to be methyleugenol. It follows that eugenol is an allyl- 

 guaiacol. — On the cholesterines of the cryptogams, by M. E. 

 Gerard. — On the distribution of pectase in the vegetable king- 

 dom and on the preparation of this diastaste, by MM. G. Bert- 

 rand and A Mallevre. Pectase may be regarded as of universal 

 occurrence in the green plants. It is especially abundant in 

 leaves, and probably spreads from the leaves to the other organs. 

 The richness of certain leaves in pectase has permitted the pre- 

 paration of this ferment. — Researches on the Tapidse, by M. 

 Pieri. — Study on the reproduction of wasps, by M. Paul Mar- 

 chal. — On a morphological modification of species and on the 

 heredity of acquired characters, by M. Remy Saint-Loup. — 

 On a disease of the sloe-tree contracted spontaneously by a 

 maple, by M. Paul Vuillemin. — On the structure and optical 



NO. I361, VOL. 53] ' 



properties of divers compa.ct or earthy silicates, by M. A. 

 Lacroix. The minerals studied, though apparently compact 

 and earthy, are formed wholly or in part of a crystallised sub- 

 stance having many of the properties of mica.— On the optical 

 isomorphism of felspars, by M. Fr. Wallerant.— Triassic am- 

 monites from New Caledonia, by M. Edmond de Mojsisovics. — 

 On the retting of flax and the microbe concerned, by M. S. 

 Winogradsky,— On the use of viper's and adder's blood as 

 antivenomous substances, by MM. C. Phisalix and G. Bertrand. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



Books.— A Manual of Physics : Dr. W. Peddie, 2nd edition (Baillierc).— 

 Thirteenth Annual Report of the Fishery Board for .Scotland. Part 3. 

 Scientific Investigations (Edinburgh, Neill). — Mechanics, Hydrostatics : 

 R. T. Glazebrook (Cambridge University Press). — Cambridge Natural 

 History. Vol. v. Peripatus, Myriapods, Insects : A. Sedgwick, F. G. 

 Sinclair, and D. Sharp (Macmillan).— Molecules and the Molecular Theory 

 of Matter : A. D. Risteen (Ginn, Boston).— On the Densities of Oxygen and 

 Hydrogen, and on the Ratio of their Atomic Weights : Dr. E. W. Morley 

 (Washington). — Elementary Inorganic Chemistry : Prof. A. H. Sexton, 4th 

 edition (Blackie).— Earth-Knowledge : W. J. Harrison and H. R. Wake- 

 field, Part I, pth edition (Bl.ickie). — Food and its Functions: F. Knight 

 (Blackie). — Mmerals and how to Study them : E. S. Dana (^Chapman). — 

 Grundgesetze der Molekularphysik : T. H. Schwartze (Leipzig, Weber).— 

 Sur rOrigine du Monde : H. Faye, troisieme Edition (Pans, Gauthier- 

 Villars). — Essais sur la Philosophie des Sciences. Analyse- M^canique : C. 

 de Freycinet (Paris, Gauthier-Villar.s). — First Stage Mechanics : F. Rosen- 

 berg (Clive). — Observaciones de Precision con el Sextante, Conde de Caiiete 

 del Pinar (Madrid, R. Alvarez).— The Wild Fowl and Sea Fowl of Great 

 Britain : A Son of the Marshes (Chapman). 



Pamphlets. — Cantor Lectures on Commercial Fibres : Dr. D. Morris 

 (Trounce). — An Account of the Smith.sonian Institution (Washington). —The 

 Exhibit of the .Smithsonian Institution at the Cotton States Exposition, 

 Atalanta, 1895 (Washington). — Christian Huygens : J. Bosscha (Leipzig, 

 P^ngelmann). — The Common Crow of the United .States : W. B. Barrows 

 and E. A. Schwarz (Washington). 



Serials. — Natural Science, December (Rait). — Longman's Magazine 

 December (Longmans). 



CONTENTS. PAGE 



The "Times" on the Scientific Situation . . • ■ 73 

 Earth-Worms and Stream-Worms. By W. B. 



Benham . 74 



Dynamics. By G. H. B 75 



Our Book Shelf:— 



Carter: " The People of the Moon " 77 



Scudder : " Frail Children of the Air."— W. F. K. . ^^ 

 Seeley : " The Story of the Earth in Past Ages"' . . . "jj 

 Letters to the Editor:— 



Remarkable Sounds.— C. Tomlinson, F.R.S. ... 78 

 The Story of the "Wandering Jew."— Kumagusu 



Minakata 7^ 



• Dr. Baur and the Galapagos.— W. Bolting Hemsley, 



F.R.S 78 



A Bright Meteor.— R. Sheward 78 



A Long Drought.— H, Helm Clayton 78 



The Pressure of a Saturated Vapour as an Explicit 



Function of the Temperature.— Dr. G. Bakker . . 79 

 Metallic Resistance and Radiation.— Prof. Oliver J. 



Lodge, F.R.S 79 



" L'Arithmetique Amusante." — William Lucas; 



Prof. G. B. Mathews 79 



The Society of Medical Phonographers.— Dr. James 



Neil 79 



The Royal Commission on Secondary Education. By 



Dr. Henry E. Armstrong, F.R.S 79 



Pagan Ireland. {Illustrated.) 82 



The Metric System of Weights and Measures ... 84 



Notes 86 



Our Astronomical Column: — 



A New Comet 9° 



Comet Perrine 90 



Variable Star Clusters 9^ 



On a Method of Photography in Natural Colours. 



{Illustrated.) By Dr. J. Joly, F.R.S 91 



Comet Magnitudes 93 



University and Educational Intelligence 93 



Scientific Serials 94 



Societies and Academies 94 



Books, Pamphlets, and Serials Received ...... 96 



