552 



NA TURE 



[April lo, 1890 



illumination with that of the standard light. Experiment had 

 shown that the sensitiveness of the instrument is greatest when 

 the difference of the contrasted illuminations is 3 per cent., and 

 amounts then to \ per cent. He further gave an account of 

 experiments which he and Dr. I.ummer had made on the 

 utilization of glow-lamps as standards of comparison. When fed 

 by accumulators these lamps yield a light which only varies by i 

 per cent, during a period of 200 hours provided the E. M. F. of the 

 accumulators is kept constant. The authors are now busy with 

 the endeavour to construct a standard glow-lamp for comparison 

 with unknown sources of light. Dr. Lummer demonstrated 

 Abbe's apparatus for testing transparent films with plane- 

 parallel surfaces. After briefly describing the interference 

 phenomena produced by thick plane-parallel glass plates, he 

 explained how Tizeau's bands and Newton's rings are employed 

 for testing the plates, using monochromatic sodium-light. The 

 light passes through a reflecting prism and through a lens, and 

 then falls on the plate, from which it is reflected and passes back 

 by the same path to the eye, being now passed through a second 

 lens by means of which the bands or rings may be seen. The 

 occurrence of interference-bands is entirely dependent upon the 

 thickness of the plate : if this is absolutely uniformly thick 

 throughout, the interference phenomena show no change if the 

 plate is moved from side to side in its own plane, and by so 

 doing the parallelism of its sides may be rapidly tested. 



Amsterdam. 



Royal Academy of Sciences, February 22. — Prof, van de 

 Sande Bakhuysen, in the chair.- — Prof. Behrens added a number 

 of reagents for microscopical analysis to those already known 

 from former publications by himself and MM. Streng and 

 Haushofer : — 



For K and Na : sulphate of bismuth. 



,, Ba, Sr, Ca : chloride of tin and oxalic acid. 



,, Ba, Sr : bichromate of ammonium. 



,, Sr, Ca, Mg : tartrate of sodium and potassium. 



,, Al : fluoride of ammonium and sulphate of thallium. 



,, Be : chloride of mercury and oxalic acid. 



, , Ce, La, Di : oxalic acid, ferrocyamide of potassium. 



,, Zn, Ca : acetate of aluminium and oxalic acid. 



,, Zn, Cn, Co: sulphocyanide of mercury and ammonium. 



,, Co, Ni : nitrite of potassium and acetate of lead. 



,, Pb, Bi, Fe : bichromate of potassium and potash. 



,, Bi, Sb, Sn : oxalic acid, chloride of rubidium. 



,, Sb, Sn, Ti : chloride of barium and oxalic acid. 



Details will soon be published, when the necessary finish has 

 been given to the methods for separation, hitherto somewhat 

 neglected. — M. Martin read a paper on the geology of the Kei 

 Islands, and, in connection therewith, on the Australian-Asiatic 

 boundary line. In accordance with the fact that in Great Kei 

 we meet with nothing but a Tertiary formation, and that the 

 nature of the rocks of Great Kei agrees with that of the coast of 

 New Guinea, M. Martin inferred that this boundary line must 

 be drawn geognostically, to the west of Great Kei and to the 

 north-west of Timor.- — Dr. Beyerinck treated of the luminous 

 food and the plastic food of phosphorescent Bacteria. Of the 

 six species of phosphorescent Bacteria hitherto known, four — viz. 

 the alimental gelatine non-melting Bacterium phosphorescens and 

 B. PJliigeri of luminous fish, and the Baltic phosphorescent 

 Bacteria, B. Fischeri and B. balticum, require, besides peptone, 

 a second carbonic combination, as glycerine, glucose, or aspa- 

 ragine, for their complete nourishment, i.e. to "phosphoresce" 

 and grow. They may be called peptone-carbon- bacteria. The 

 gelatine quick-melting phosphorescent bacteria from the West 

 Indian Sea and the North Sea, B. indicum and B. luminosum, 

 can phosphoresce and grow on peptone alone. They are, there- 

 fore, peptone-bacteria. Again, other bacteria can derive their 

 nitrogen either from amids, the amid-bacteria, or from ammoniac, 

 the ammoniac-bacteria. Also moulds, yeasts, and some 

 Protozoa may be classed in this system. The Bacterium PJliigeri 

 does emit light with peptone and glucose, but not with peptone 

 and maltose, while the Bacterium phosphorescens emits light 

 both with glucose and maltose. Now if we mix some starch in 

 a phosphorescens-peptone-gelatine, obtained by mixing this 

 gelatine with a very great number of B. phosphorescens, and 

 place upon this some ptyaline, pancreas-diastase, or urindiastase 

 (nefrozymase), fields of light make their appearance ; if, however, 

 we placed these same sorts of diastase on a Pfliigeri-peptone- 

 starch-gelatine, then no fields of light would appear, which 



proves that in this instance no glucose whatever is formed, as 

 was lately believed to be the case. The development of 

 luminosity is constantly accompanied by the transition of pep- 

 tones into organized, living matter, under the influence of free 

 oxygen, with or without the concurrence of another carbonic 

 combination. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



Among the Selkirk Glaciers : W. S. Green (Macmillan). — Flora Tangutica, 

 fasc. i. : C. J. Maxiniowicz (Petropoli). — Enumeratio Plantarum Hucusque 

 in Mongolia, fasc. i. : C. J. Maxiraowicz (Petropoli). — The Human Epic, 

 Canto i. : J. F. Rowbotham (K. Paul). — Agende de Chimiste, Salet, Girard 

 and Pabst (Hachette). — 1 he Theory of Determinants in the Historical Order 

 of its Development ; Part i.. Determinants in General : T. Muir( Macmillan). 

 — The Microtomist's Vade-Mecum, 2nd Edition : A. B. Lee (Churchill). — 

 Guide Pratique de L'Am.ateur !^lectricien : E. Keignart (Paris, Michelet). — 

 Musiconomia o Leggi Fondamentali della Scienza Musicale : P. Crotti 

 (Parma, Battei). — I/Eclairage Electrique Actuel, 2nd Edition : J. Couture 

 (Paris, Michelet). — Das Reizleitende Gewebesystem der Sinnpflanze ; Dr. G. 

 Haberlandt (Leipzig, Engelmann). — Traite Ency. de Photographic, 15 Mars : 

 C. Fabre (Paris, Gauihier-Villars). — Proceedmgs of the Aristotelian Society, 

 vol. i. No. 3, Part i (Williams and Norgate). — Mind, April (Williams and 

 Norgate). — Geological Magazine, April (K. Paul). — Quarterly Journal of 

 Microscopical Science, April (Churchill). — Journal of the Royal Agricultural 

 Society of England, 3rd Series, Part i (Murray). — Journal of the Royal 

 Horticultural Society, vol. xii. Part i (London). 



CONTENTS. PAGE 



New Light from Solar Eclipses. By William E. 



Plummer 529 



The Evolution of Sex. By P. C, M 531 



The Quicksilver Deposits of the Pacific Slope. By 



H. B 532 



Our Book Shelf:— 



Coldstream : " Illustrations of some of the Grasses of 



the Southern Punjab,"— J. G. B 533 



Hicks : " Elementary Dynamics of Particles and 



Solids."— G. A. B 534 



Lydekker : " Catalogue of the Fossil Reptilia and 



Amphibia in the British Museum " 534 



Letters to the Editor : — 



Systems of " Russian Transliteration." — Charles E. 

 Groves, F.R.S. ; W. F. Kirby ; H, A. M. and 



J. W. G 534 



"Like to Like" — a Fundamental Principle in Bio- 

 nomics. — Prof. George J. Romanes, F.R.S. ; 



John T. Gulick 535 



Self-Colonization of the Coco-nut Palm. — W. 



Botting Hemsley, F.R.S 537 



On Certain Devonian Plants from Scotland. — Sir J, 



Wm. Dawson, F.R.S 537 



Exact Thermometry. — Dr. Edmund J. Mills, 



F.R.S 537 



The Shuckburgh Scale and Kater Pendulum. — O. H. 



Tittmann 538 



The Green Flash at Sunset.— C. Michie Smith . . 538 

 Foreign Substances attached to Crabs. — Walter 



Garstang 538 



The Thames Estuary. ( With Maps.) By Captain 



T. H. Tizard, R.N 539 



Notes 544 



Our Astronomical Column : — 



Objects for the Spectroscope. — A. Fowler 548 



The Apex of the Sun's Way 548 



Stability of the Rings of Saturn 548 



Brooks's Comet (a 1890) 549 



Bright Lines in Stellar Spectra 549 



On the Deformation of an Elastic Shell. By Prof. 



Horace Lamb, F.R.S . 549 



Scientific Serials 549 



Societies and Academies 550 



Books, Pamphlets, and Serials Received 552 



