384 



NATURE 



[August 14, 1890 



to a well-known species. Mr. Stainton, F.R.S., Mr. Jenner- 

 Weir, and Colonel Swinhoe made some remarks on the speci- 

 men, and commented on the additions to the list of butterflies 

 captured in the United Kingdom which had been made of late 



years. Mr. W. F. H. Blandford exhibited, and made remarks 



on, five specimens of Athous rhombms, Ol., recently collected 

 by' himself in the New Forest. — The Rev. Dr. Walker exhibited 

 a large collection of Coleoptera which he had recently made in 

 Iceland. The following genera, amongst others, were represented, 

 viz. Patrobus, Nebria, Byrrlms, Aphodius, Philonthus, Bary- 

 nofus, Chrysomela, Agabtis, Creophilus, and Carabus. Mr. 

 Champion, Dr. Sharp, F.R.S., and the Chairman made some 

 remarks on the collection. — Captain Elwes exhbited three species 

 of the genus Atossa, Moore, three of the genus Elcysma, Bull., 

 and three of the genus Campy lotes. West.,— all from the Hima- 

 layas and North-Eastern Asia. The object of the exhibition was 

 to illustrate the remarkable differences of venation in these closely- 

 allied forms of the same family. Colonel Swinhoe, Mr. Warren, 

 and Mr. Moore took part in the discussion which ensued. — Mr. 

 P. Crowley read a paper entitled " Descriptions of Two New 

 Species of Butterflies from the West Coast of Africa," and ex- 

 hibited the specimens, which he proposed to name respectively 

 Charaxes gabonica and Cymothoe marginata. He also exhibited 

 several other new species from Sierra Leone, which had been 

 recently described in the Annals and Mag. of Nat. Hist, 



Paris. 

 Academy of Sciences, August 4. — On the exhaustion of 

 land by culture without manure ; study of drainage waters, by 

 M. P. P. Deherain. — Observations of Coggia's comet (July 18, 

 1890) made with the Brunner equatorial of Toulouse Observa- 

 tory, by M. E. Cosserat. Observations of position were made 

 on July 21 and 22. — Elements and ephemeris of Denning's 

 comet (July 23, 1890), by M. Charlois. The elements have 

 been calculated from observations made at Nice on July 24, 28, 

 and 30. — Resume of solar observations made at the Royal 

 Observatory of the College of Rome during the second quarter 

 of 1890, by M. P. Tacchini. (See Our Astronomical Column.) 

 — On the density of nitrogen and oxygen according to Regnault, 

 and the composition of air according to Dumas and Boussin- 

 gault, by M. A. Leduc. The author draws attention to a 

 difference between the results obtained by Regnault and by 

 Dumas and by Boussingault. If x = the proportion of oxygen 

 in 100 volumes of air, d and d' the densities of oxygen and 

 nitrogen, then 



dx + d{\oo - x) = 100, and x = — -J^ — — — '. 



Replacing d and d' by Regnault's values (d — i •10563 and 

 d' = 0-97137), we get 



X = 21 "324, 



and for the percentage composition of air by weight. 



Oxygen = 23*58, and Nitrogen = 76 •42. 



Dumas's mean value was 23*0 ± o*i, and the author throws out 

 several suggestions as to the probable cause of the discordance. 

 He has also made some determinations of the density of nitrogen, 

 and obtained values comprised between 0-972 and o"973. — 

 Electrical resistances of gases in a magnetic field, by M. A. 

 Witz. The author has previously communicated his researches 

 on the action of magnetic fields on Geissler tubes (May 12, 

 1890), and has studied the effects produced by variations in the 

 intensity of the magnetic field and the position of the tube with 

 respect to the lines of force ; he has now determined the influence 

 exercised by changes in the pressure of the gas in the tube. The 

 experiments have led to the conclusion that the action of magnets 

 upon Geissler tubes is due to a variation in the capacity of the 

 tubes, so that they constitute true condensers, and their illumina- 

 tion is the result of an oscillatory discharge of the same order 

 as that of a Leyden jar, of which the period T is a function of 

 the capacity C of the jar, and of the coefficient L of self-induction 

 of the conductor of small resistance, and T = tt y/CL. A varia- 

 tion of the capacity C would thus modify the vibratory 

 state of the, gas and would be the cause of the differences 

 observed in the luminous phenomena in intense magnetic fields. 

 — Reactions of alkaloid salts, by M. Albert Colson. Some in- 

 vestigations on heats of formation are given. — On the division of 

 sulphuretted hydrogen between the metals of two dissolved salts, 



NO. 1085, VOL. 42] 



by M. G. Chesneau. — On some derivatives from acetylacetone, 

 by M. A. Combes. — Experimental researches on thermic sensi- 

 bility, by M. Charles Henry. — Experimental researches on 

 the affected nerves of chronic lead poisoning, and on the causes 

 determining their appearance, by MM. Combemale and Fran9ois. 

 — On the combinations of hemoglobin with carbonic acid, and 

 with a mixture of carbonic acid and oxygen, by M. Christian 

 Bohr. — On the colouring of the silkworm by feeding, by M. 

 Louis Blanc. From the investigations it would appear that very 

 soluble and diffusible substances, such as fuchsin, are absorbed 

 by the epithelium intestinal of the silkworm, and colour the cells 

 of the secretory organs, but not the product of secretion. — On 

 the cellular division of Spirogyra orthospira, and on the re- 

 arrangement of the colouring matters driven to the ends of the 

 spindle, ^by M. Degagny. — The treatment of black rot, by M. 

 A. del'Ecluse. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



La Photographic Judiciaire : A. Bertillon (Paris, Gauthier-Villars).— 

 British Cage Birds. Part 4 : R. L. Wallace (U. Gill).— The Canary Book, 

 Part 4 : R. L. Wallace (U. Gill).— The Elements of Solid Geometry : R. 

 B. Hayward (Macmillan). — Les Facultes Mentales des Animaux : Dr. F. 

 de Courmelles (Paris, J. B. Bailliere).— English-Eskimo and Eskimo-English 

 Vocabularies: R. Wells and J. W. Kelly (Washington).— Photogravure : W. 

 T. Wilkinson (Uiffe). — Bulletin from the Laboratories of Natural History of 

 the State University of Iowa, Vol. i., Nos. 3 and 4 (Iowa). — Journal of 

 Physiology, Vol. xi., Nos. 4 and s (Cambridge). 



CONTENTS. PAGE 



The Income-Tax and the Promotion of Science . . 361 

 Principles of Economics. {With Diagrams.) By 



F. Y. E 362 



Sadi Carnot's Essay. By P. G. T 365 



Triassic Fishes and Plants, By A. S. W. and 



J. S. G 366 



Sea Anemones of the North Atlantic 367 



Our Book Shelf:— 



"Smithsonian Report, 1887" 368 



Earth : ' ' Travels and Discoveries in North and 



Central Africa" 368 



Toynbee : '* Weather Forecasting for the British 



Islands " 368 



Woodbury: " The Encyclopaedia of Photography " . 368 



Inagaki : "Japan and the Pacific " 368 



Letters to the Editor : — 



Indiscriminate Separation, under the same Environ- 

 ment, a Cause of Divergence. — Rev. John T, 



Gulick 369 



The Affinities of Heliopora ccerulea.—Hx. Sydney J. 



Hickson ... • 370 



Meteors. — W, J. Lockyer 370 



A Liquid Compound of Nickel and Carbon Mon- 

 oxide. By A, E. Tutton 370 



British Museum Natural History Publications. 



{Illustrated.) 371 



The Australasian Association for the Advancement 



of Science 374 



Notes 374 



Our Astronomical Column : — 



Objects for the Spectroscope.— A. Fowler 377 



Lightning Spectra. {Illustrated.) 377 



Solar Activity 378 



Denning's Comet {c 1890) 378 



Geographical Notes 378 



The Scientific Principles involved in making Big 

 Guns. III. {Illustrated.) By Prof. A. G. Greenhill, 



F.R.S 378 



On Putrefactive Organisms. By Dr. W. H. Dal- 



linger, F.R.S 381 



Highland Plants from New Guinea. By Baron von 



Mueller, F.R.S 382 



Scientific Serials 383 



Societies and Academies 383 



Books, Pamphlets, and Serials Received 384 



