144 



NATURE 



[June i i. 



Paris. ' ' ' 



Academy of Sciences, June i.— M. Duchattre in the 

 chair.— Calorimetric researches on humic acid derived from 

 sugar, by MM. Berthelot and Andre. The experiments show 

 that humic acid is a polybasic acid which may be caused to unite 

 with three equivalents of potash to form insoluble salts : one salt 

 described is monobasic, stable, and formed with the evolution 

 of i8 calories, an amount comparable with that evolved 

 when alkaline salts are formed by the action of strong acids. 

 Many other properties of this acid are given. — Analysis of the 

 light diffused by the sky, by M. A. Crova. The observations 

 recorded extend from December 1889 to the same month in 1890. 

 From the results it appears that the blue colour of the sky is most 

 intense in the months of December, January, March, and Septem- 

 ber; and shows minima in July, August, and November. Roughly, 

 the blue colour is deepest in the winter, and palest in summer ; 

 spring and autumn give sensibly the same results. A comparison 

 of the intensities at different hours of the day indicates that a 

 maximum blue coloration occurs in the morning and a minimum 

 at the hottest hour in the day.— On Abelian equations, by M. A. 

 Pellet. — On a new method of determining the vertical motion of 

 aerostats, by M. Andre Duboin. The methods usually employed 

 by balloonists to determine their state of vertical motion are 

 by means of a barometer, or by throwing out light bits of paper 

 and observing whether they ascend or descend relatively to the 

 balloon. The author has devised an apparatus having the same 

 object, on the principal of Kretz's differential manometer, and 

 claims for it a sensibility 150 times greater than the ordinary 

 mercurial barometer.— New models of copper oxide batteries, 

 by M. F. de Lalande. A 35 per cent, solution of potash is the 

 liquid employed. In it dips a conglomerate of copper oxide and 

 sand covered with a thin porous layer of metallic copper, and 

 one or two zinc plates. A cell thus constituted is shown to be 

 practically constant for three or four days, and is said to work 

 for years without getting out of order. — Determination of mole- 

 cular weights at the critical point, by M. Philippe A. 

 Guye. Using Van der Waals's formula, the author deduces 



[I46- 



, where d is the critical density with respect 



ir(i67o -t- 0)' 



to air, 5 the critical density with respect to water — that is, the 

 weight of the substance in grams occupying a volume of one 

 cubic centimetre at the critical state— the absolute tempera- 

 ture, and -K the pressure in atmospheres. It is then shown that 

 the values of d obtained by means of this empirical formula 

 are equal to the molecular weights of the substances investigated 

 divided by 28 '8 7. — Research on the separation of metals from 

 platinum, and in particular of palladium and rhodium in the 

 presence of common metals, by MM. A. Joly and E. Leidie. 

 The platinum or palladium are converted into soluble nitrites by 

 the addition of potassium nitrite, and are thus separated from 

 other metals. — On the specific heats of some solutions, by M. 

 W. Timofeiew. Alcoholic solutions of bichloride of mercury 

 and cadmium iodide were used. It is shown that the difference 

 between the molecular specific heat of the solution and solvent 

 is sensibly equal in the case of both salts, the mean value being 

 52. Taking this value to represent the molecular specific heat of 

 the salt in solution and the specific heats of the alcohols employed 

 to be expressed by the formulae, 



^methyl _ 0-56755 + 0-001633/ ; C<="'y' = 0-53574 + 0-002132/; 

 it is shown that the observed and calculated specific heats of the 

 solutions are very nearly the same in each case. — On the oxida- 

 tion products of uric acid, by M. C. Matignon. The heats of 

 formation and combustion of the principal derivatives of uric 

 acid are considered. — On the employment of ammonium selenite 

 for the identification of alkaloids, by M. A. J. Ferreirada Silva. 

 The use of ammonium sulphoselenite for the detection of mor- 

 phine and codeine was suggested by M. Lafon in 1885. The 

 author shows how the method can be extended to other alkaloids. 

 — On the development of the liver of Nudibranchiates, by M. 

 H. Fischer. The research shows that the liver of Nudibranchiates 

 is formed to a great extent by the left hepatic lobe of the embryo, 

 and that the hepatic organs in two very different groups of Mol- 

 lusca, the Lamellibranchiates and Nudibranchiates, are homolo- 

 gous productions. — The Isaria, a parasite of the larva of the 

 cockchafer, by M. Alfred Giard. — The genera of the group of 

 Clusia, and in particular the genus Tovomita, by M. J. Vesque. 

 — On some supporting elements of the leaves of Dicotyledons, 

 by M. E. Pee-Laby. — Diffusion of three distinct forms of 

 titanium oxide in the Cretaceous strata of Northern France, by 

 M. L. Cayeux. A microscopic examination of the residue after 



NO. I 1 28, VOL. 44] 



treating chalk with an acid leads the author to believe he hai* 

 recognized the three crystalline forms of titanium oxide — rutile, 

 anatase, and brookite. — The lichens on mulberry-trees, and 

 their influence on silk culture, by M. G. Hallauer.— On the 

 employment of carbon bisulphide against aerial parasites, by 

 M. H. Quantin. 



Amsterdam. 

 Royal Academy of Sciences, May 30.— Prof. Van de 

 Sande Bakhuyzen in the chair. — Dr. Bakhuis Roozeboom 

 treated of the solubility of mixed crystals of isomorphous sub- 

 stances. Admitting the absolute homogeneity of such crystals, 

 according to the recent researches of Retgers, it is possible to 

 deduce, by thermodynamical reasoning, that, when / and T are 

 taken as constants, equilibrium is obtained when to a proportion a 

 of the components in the mixed crystals, correspond two definite 

 values Cj and C^ for the concentrations of the components in 

 the aqueous solution. From the analogy between the said 

 equilibrium and that between a liquid and a gaseous phase, 

 composed of two substances, are further deduced some general 

 conclusions as to the behaviour of solutions of two isomorphous 

 salts when they are evaporated. This is done both for the case 

 in which the mixed crystals form a continuate series, and that in 

 which they present a hiatus. The latter was found in studying 

 the solubility of KCIO3 and TlCIOs- Solid mixtures were ob- 

 tained at 10^ and i atm. from 0-36-3 and from 97-9-ico per 

 cent. KCIO3. In the evaporation of any one solution, it tends 

 to a composition, which is necessary to deposit the two kinds of 

 crystals between which the hiatus exists. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



Bacteria and their Products : Dr. Sims Woodhead (Scott). — Einleitung in 

 die Theoretische Physik ; Zweite umg. und verm, auflage : V. von Lang 

 (Braunschweig, Viewig).— A Manual of Forestry, vol. ii. : Dr. W. Schlich 

 (Bradbury). — The British Noctuse and their Varieties, vol. i. : J. W. Tuit 

 (Sonnenschein). — Practical Work in Organic Chemistry: P. W. Stieatfeild 

 I Spon),— Katalog der Bibhoihek der Deutschen heewarte zu Hamburg (Ham- 

 burg).— Catalogue of the Fossil Birds in the British Museum (Natural 

 History) : R. Lydekker (London).— the Solar Parallax and Us Related Con- 

 stants : W. Harkness(Washingion). — favourite Foreign Birds : W. T. Greene 

 (Gill). — Anthropogeographie : Dr. F. Ratzel (Stutigart, Engelhorn). —Notes 

 on Building Construction, Part 2, new edition (Longmans). — Poachers 

 and Poaching: J. Waisun (Hal). —Modern Cremation, 2nd edition: Sir 

 Henry Thompson (Paul). — Nature and Treatment of Diphtheria, 3rd edition : 

 R. w . Parker (Lewis).— Riddles of the Sphinx : A Troglodyte (aonnen- 

 schfein).— Housing of the Puor : F. H. Millingt>,n (Cassell).— British Cage- 

 Birds, Part 14 : K. L. Wallace (Gill).— A Manual of Orchidaceous Plants, 

 Party (Veitch).— Tasmanian Official Rtcord, 1891 (Hobait).— The Birds of 

 Manitoba : _E. E. Thomp on (Washington). — Scientific Results of the Second 

 Yarkand Mission; Coleoptera(Calcutta).— Smithsonian Report. i88ij (Wash- 

 ington).— Internationales Archiv fur Ethnographic, Band 4, Htft 3 (Paul). 

 —The Asclepiad, No. 30, vol. viii. : B. W. Richardson (Longmans).— 

 Photographic Reporter, June (Haiell). 



CONTENTS. PAGE 



Mammals Living and Extinct. By Prof. E. Ray 



Lankester, F.R.S. 121 



Forty Years in a Moorland Parish 122 



Our Book Shelf :- 



Lowne : "Anatomy, Physiology, Morphology, and 



Development of the Blow-fly." — L. CM 123 



Brinton : " Races and Peoples : Lectures on the 



Science of Ethnography " 124 



Letters to the Editor :— 



Crystals of Platinum. — J. Joly 124 



Porpoises in the Victoria Nyanza. — Dr. P. L. 



Sclater, F.R.S 124 



The Zoological Station at Naples. — W. Percy 



Sladen 124 



A British Institute of Preventive Medicine .... 124 

 Earth-Currents and the Electric Railway. [Illus- 



irated.) By William Ellis 127 



The Annual Visitation of the Royal Observatory 128 

 The Classification of the Tunicata in relation to 



Evolution. By Prof. W. A. Herdman 130 



Photo-Stellar Spectra. By Rev. T. E. Espin ... 133 



Some Aspects of Stas's Work. By V. C 134 



Notes 135 



Our Astronomical Column : — 



The Spectra of Double Stars 138 



The Perseid Radiant 138 



The Flora of Diamond Island, By W. Botting 



Hemsley, F.R.S 138 



University and Educationallntelligence . . . . 138 

 Societies and Academies 139 



Books, Pamphlets, and Serials Received 144 



