192 



NA TURE 



[June 



21, 1094 



all of which he described in detail, and then dealt briefly with a 

 whole series of isolated observai ions made at a height of 1 140 m. 

 that is, at the level of the lower clouds. The phenomena 

 touched upon were the formation of rime, force of the wind, 

 sequence of depressions, and maxima of pressure, &c. The 

 ou'cofne of his remarks showed the necessity for a properly 

 equipped station on the Brocken, under expert management. 

 One point of interest may be mentioned, namely that on the 

 Brocken, during an anticyclone the lowest temperature was 

 always observed at the beginning, followed by a rise of tem- 

 perature in the second half of the period, whereas, as is well 

 known, on the plains the tempeiature continues to fall right to 

 the very end of the anticyclone. 



Physical Society, May 4. — Prof. d« Bois Reymond, Pre- 

 sident, in the chair. — Dr. Pringsheim alluded in appropriate 

 terms to the death in Brooklyn of their foreign member Dr. F. 

 SchulzeBerge. — Prof. Konig spoke on the number of distinct 

 diflferences of colour and brightness which can be discriminated 

 in the spectrum. He had made experiments in conjunction 

 with Prof. Dieterici, subsequently verified by Prof. Uhthof, on 

 the mean error existing when matching two tints, and from this 

 he had been able to deduce the total number of differences in 

 tint which a normal trichromatic eye can discriminate from the 

 red to the blue end of the spectrum. Sensitiveness 10 difference 

 of lint showed two maxima, one in the yellow and one in the 

 greenish-blue, and the total number of distinct differences dis- 

 criminated was 165. A dichrnmatio eye, on the other hand, 

 can only discriminate 140 differences. Experiments of the 

 speaker and of Dr. Biolhun formed the basis for determining 

 the number of differences of brightness which can be discrimi- 

 nated, starting with liminal light and increasing it up to a blinding 

 intensity. For both ihetri- anddi-chromaticeye the number was 

 found to be 650. If it be desired to deduce from the above data 

 the total number of possible visual differences which can be dis- 

 criminated in a spectrum, it must be remembered that as the 

 intensity r.f light diminishes, so also does the number of dis- 

 criminaud lints, so that the result is in round numbers 

 83 X 700 = 56,000. In connection with the above. Prof, von 

 Bizold suggested that by using complementary colours it maybe 

 possible to discriminate a much larger number of tints, since, as 

 is well known, two colours which are indistinguishable when 

 compared directly often give (juite different complementary 

 -colours, and can thus be distinguished. 



Physiological Society, May 11. — Prof, du Bois Reymond, 

 President, in the chair. — Dr. .Max Verworn spoke on the polar 

 excitation of cells by galvanic currents. Unicellular fresh- 

 water infusoria (Paramcecium) were experimented on, and 

 showed always, un making a constant current, cathodic 

 galvanotropism ; by this is meant that all the infusoria in a 

 drop of water placed themselves with their anterior end towards 

 the cathode. They then moved towaids and congregated at 

 the cathode. When the direction of the current is reversed the 

 infusoria turn r)und and move away towards the new cathode. 

 When strong currents are employed it is found that the hinder 

 end of the organism is contracted, and if Ihe stimulation is pro- 

 longed the protoplasm is disintegrated. From this the speaker 

 drew the conclusion that the infusoria are anodically excitable, 

 and that the cathodic galvanotropism is due to anodic slimu- 

 lalion. The exact reverse holds good for Opalina, since they 

 are cathodically excitable and anudically galvanotropic. A 

 third group of infusoria (Spirostomum) is transversely galvano- 

 tropic. — Dr. Lilienfcld gave an account of his researches on the 

 cl itting of blood. lie had succeeded in separating Al. 

 Schmidt's fibrinogen into two substances, "tbrombosin" and 

 an albumose. The former unites with calcium and forms 

 fibrin, while the albumose retards clotting. The separation of 

 fibrinogen into these two constituents may be brought about by 

 means of acetic acid, nuclein, nucleic acid, and other sub- 

 slancei. Blood-clotting accordingly consists in a disintegration 

 of leucocytes setting free nuclein ; the latter then decomposes 

 the fibrinogen, and enables the thrombosin to unite with the 

 calcium salts of the blood. While the blood is circulating in 

 Ihe bo<ly it contains no free nuclein in solution, and hence 

 dolling is impoj.-ible. The speaker further considered that 

 peptones (albumose) and lecch-exiract prevent clotting by 

 themtelves uniting with the calcium of the blood, and thus 

 prevcnling its union with thrombosin. 



Ni'ti. — In the report of the meeting of the Meteorological 

 .Society for April 3 (Nature, vol. I. p. 95), for Kaisner read 

 Kuiner, and for Hasen read Ilazcn. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



U'->OKS. — .\ Pocket FIor;i of Edinburgh ; C. O. SonntaL; (WiUiaiiis .iiid 

 Noryate). — Projf Sp'rit and Fiscal Hydrotnetry : Dr. B. l'erhan»(l. Hey- 

 \*-ood) — A Handbook to the Study of Natunii History ; edited by Lady I. 

 Margesson (Phil.p) — Coloured Vade-Mccutn to the Alpitie Flora: L. and 

 C. Schroter, 4th edition (Nutt). — Grundzfigc dep Geometrie : Prof. G. 

 Veronese (Leipzig, Teubner) — Catalogue of Scientific Papers (1S74-18R3) 

 compiled by the Koval Society of I-ondon, Vol. x. (C. J. Clay). — Epitome 

 of the Synthetic Philosophy ; F. H. ColLns, 3rd editijn (Williams and Nor- 

 Rate). — Report of the Melco'ological Service of Canada for the Year ending 

 December 31, 18S9 (Ottawa)— Zur Fossilen Flora der Polarlandei : A. O. 

 Nathorsl (JitocUholn, Norstedt). — Elementi di Fisica ; Prof. A. Koiti, 

 Vol. Primo (Firenze. Monn-er) — Zeit-und Streitfraeender Biologic : Prof. 



0. Hertwig, Hcfi I (Jena, Fischer). — Synopsis der Hoeheren Mathematik : 



1. G. Hagen, Zweit-r Band (Berlin, Dames). — Les Oscillations l^lectriques; 

 H. Poincarfi (Paris. Carre).— Geological Sketch Map of Western Australia: 

 H. P. Woodward (Philip). — .\ Dictionary of Medicine: edited by Sir R. 

 (^)uain, &c , 2 Vols., new edition (Longmans). —The Physiology of the 

 Caibohydratcs : Dr. F. \V. Pavy (Churchill). 



PrtMF'HLET,-. — Protection from Lightning: A. McAdie (Washington) — 

 The Yellowstone Park : A. Hague (Washington) — Leitncria Kloridana : 

 W. Trclease (St. Louis) — Weifre Lichtelectrische Versuclie : J. Elster and 

 H. Geitel (Leipzig. Barth). — Report of Mr. Tebbutl's Observatory, the 

 Peninsula, Winds >r. N.S.W.. for the Ve.ir 181)3; J- Tebbutt (Sydney). 



Serials. — Jou'nalof the Chemical Society,June(Gurney and Jackson) — 

 Transactions of the Academy of Science of St. Louis, Vol. vi. No. 15(^1. 

 Louis' — Journal of the Franklin Institute, June (Philadelphia) — Astronomy 

 and Astro- Physics, June(Wesley). — American Naturalist, June (Wesley) — 

 lingineering fllagazine, June (Tucker). — Bulletins de la Socui i: d*.-\nthro- 

 pologie de Paris, Mars (Paris). — Quarterly J0urn.1I of Microscoiiical Science, 

 June (Churchill)-— tntlcs. .Archiv fiir Ethnographic, Band vii. Heft 3 

 (Leiden, Brill).— Journal of the Institution of Electrical Kngineers, No 11 .f, 

 Vol. xxtii. (Spon). — Bulletin de la Sociiitii Iinpiirialc des Natura'isles de 

 Moscou, 1804, No. I (Moscou). — Royal Natural History. Part 8 (Warre).— 

 Zcitschrift fiir Physikalische Chemie, xiv. Band, 2 Heft (Leipzig, Ens'l- 

 mann). — L'Anlhropolopie, trme v. No. 3 (Paris, Masson). — Field an.l 

 Garden Crops of the North-West Provinc.-s and Oadh : J. F. Dulhir 

 Part 3 (Roorkee). 



NO. I 286, VOL 50] 



CONTENTS. PAGE 



The Brothers William and John Hunter 169 ■ 



Gold 170 ' 



Our Book Shelf:— 



Bird: " (Jeology " 171 



"The New Technical Educator" 17' 



Letters to the Editor: — 



The Ilodgkins Fund Prizes.— Prof. S. P. Langley 171 

 Llectrical Theoryof Vision. — Prof. Oliver J. Lodge, 



F.R.S. ; Dr. E. Obach 17a ' 



Ophiophagus. — Sir J. Fayrer, K.C.S.I., F.R.S. . 17a ■ 

 Mohl's " Primordial Utricle."— Thomas Hick . . 173 1 

 Hailstones at Cleveland, Ohio. {Illustraltd.) — 



Francis H. Herrick 173 1 



Finder Circles for F,quatorials. — Prof. Wm. Hark. 



ness • 173 i 



On the Use of Quartz Fibres in Telescopes. — Dr. L. 



Bleekrode I74 ■ 



Bullet-I'roof Shields.— Rev. Frederick J. Smith, 



F.R.S 174 1 



The Horn Expedition forthe Scientific Exploration 



of Central Australia 174 1 



The Enrichment of Coal-Gas. By Prof. Vivian B. 



Lewes 17S 



Notes 177 : 



Our Astronomical Column : — 



Brighl-I.ine Stars 181 1 



Kphcmeris for Gale's Comet ■ • • '81 1 



The Royal Society Conversazione i8a ! 



A Chemical Method of Isolating Fluorine. Uy A. 



E. Tutton 183 ■ 



A Survey of the English Lakes, liy Dr. H. R. 



Mill 184 



The Recent Discovery of Fossil Remains at Lake 

 Callabonna, South Australia. I. {/lluityaltd.)) 



By Dr. E. C. Stirling, C.M.G., F.R.S 184 ' 



University and Eduotional Intelligence 188 



Scientific Serials '88 



Societies and Academies 188 



Books, Pamphlets, and Serials Received 192 



