240 



NATURE 



[July 5, 1S94 



recorded who?e chnracters do not agree with those of the three 

 species recognised by Oliver and Bentham (but united by Baron 

 von Mueller) ; and ihe whole five are figured. — List of mollu'^ca 

 collected at Green I'oint, Watson's Bay, by A. U. Menn, with 

 descriptions of new species, by John Brazier. The specimens 

 on which this list is based (in number 1365, representing 154 

 species) were contained in a discarded bottle found in a rock 

 pool accessible only at very low tide?. A genus new to 

 Australia and several new species were recorded. — On a new 

 Fate'.'a said to have been found at the Kermadec Islands, by 

 Tohn Br.izier. — On a new .-Vustralian Croton and on a supposed 

 new species of Acacia, by J. H. Maiden and K. T. Baker. — 

 Cnder the name of C. affinis, a species allied to C. 

 acrcfiychioiJ/s, from near Tintenbar, was described. It differs 

 from the latter species in the number and length of the stamens, 

 the marked occurrence of peials, the persistent calyx under the 

 fruit, the shape of the capsule (broader than long), which is both 

 furrowed and deeply lobed, and the thin texture of the leave;;. 



Amsterdam. 

 Royal Academy of Sciences, May 26. — Prof, van de 

 Sande Bakhuyzen in the chair. — Some observations on oxygen, 

 by I. H. van't Hoff. — The remarkable fact that ga-eous 

 oxygen sometimes exhibits more energetic chemical activity in 

 the dilute than in the more concentrated condition, has been 

 investigated in van't HofTs laboratory by Dr. Ewan, the course 

 of the slow oxidation of sulphur and of phosphorus being 

 selected for study. With phosphorus and oxygen (saturated 

 with aqueous vapour at 20°) it was observed that for pressures of 

 oxygen greater than 700 mm. the velocity of oxidation is ex- 

 cessively small or nothing at all. Below 700 mm. it increases 

 very rapidly. This limit corresponds to that found by loubert, 

 below which phosphorescence begins. After reaching its 

 maximum velocity a very simple relation exists between the 

 rate of oxidation and the pressure of the oxygen, provided that 

 the change in the rate of evaporation of the phosphorus, which, 

 according to Stefan, is produced by the change in pressure, is 

 taken into account. The rate of oxidation is then directly pro- 

 portional to the pressure of the oxygen. In absence of water the 

 oxidation also begins suddenly, but at a lower pressure (about 

 200 mm.). Taking into account the change in the rate of 

 evaporation, the velocity of oxidation then reaches a maximum 

 at a pressure which is approximately the same as that which van't 

 Hoff formerly found to be the most favourable for the explosive 

 combustion of phosphine. After the maximum the relation between 

 the velocity of the reaction and the pressure could not be made 

 out with certainty, because in dry oxygen the coating of oxide 

 which forms on the surface of the phosphorus disturbs the 

 regular course of the reaction. With sulphur and dry oxygen, 

 where the slow oxidation can be conveniently followed at 160', 

 this relation has, however, been obtained. It appears, again 

 taking into account the change in the velocity of evaporation, 

 that the velocity of the oxidation is proportional to the square 

 root of the pressure. This would appear to point to the con- 

 clusion that in the absence of water, the active part of the 

 oxygen is only that very small part of it which is broken up 

 into atoms. This conclusion is perhaps supported in the case 

 of phosphorus by the compo-ition of one of the products of the 

 oxidation in dry oxygen, viz. P/J). — Mr. Ilakhuis Roozeb.iom 

 iluciiBsed the equilibrium of solutions and solid phases formed 

 of the system: HC1,I1,0 and FcjClj. In a three-dimensional 

 reprc»cniation the solutions which may coexist with a hydrate 

 of Fc.Clj form a vault, whose summit lies in the inching point 

 of the hydrate ; the isotherms are not unlike half a circle. 

 With a C'>mpound of the three components, solutions may coexist, 

 wboie compositions are represented for each temperature liy a 

 closed curve, surrounding the point which indicates the com- 

 po«iiion of the solid compound. Two of these were iliscovercd : 

 Fe/:!, . 2HCI . 8H,0.-ind FeXI, . 2MCI, I2ll,0 ; melting 

 points: — 3" and - 6'. The different ways in which the vaults 

 for all the existing solid pha.Hes may encounter are discussed. — 

 By diagrams and mo<lel> Dr. Schoule >howed that the natural 

 connection between the homogeneous divisions of space by 

 means ol cubes and of orihic tclraikaidekahedra (set Lord 

 Kelvin's paper in NATtrRF,. March 8 and 15. 1894) is given by 

 the known theorem, that the plane, orthogonally bisecting a 

 central diagonal of the cube, cuts it in a regular hexag in. 

 I'-vcry cuf>e of a given homogeneous division in cubes, we 

 divide into eight c'lual minor cubes by means of three planes, 

 parallel to the faces. In each of thevc eight minor cubes wc 

 draw the central diagonal ending in the centre O of the original 



NO. 1288. VOL. sol 



cube, and we divide these into two equal parts by means of 

 planes orthogonally bisecting the diagonals. In this manner 

 every original cube is divided into sixteen equal parts. The 

 eight parts that surround the centre O of the original cube form 

 a tetrakaidekahedron. The remaining "intercellular" parts 

 form equal tetrakaidekahedra, the centres of which are the 

 vertices of the original cubes. — Mr. Kamerlingh Onnes com- 

 municated the results of further experiments made by Dr. 

 Kuenen in the Leiden Laboratory, "on the abnormal pheno- 

 mena near the critical point." Dr. Kuenen has explaineii the 

 abnormalities observed by Zambiasi,de Heen, and others, by im- 

 purities of the matter used. He has now repeated with the 

 utmost care the experiments, from which Galilzine drew the 

 startling conclusion, that ether above the critical temperature 

 has very different densities according to its having been before 

 entirely fluid or partly vapour. The differences found by Dr. 

 Kuenen in the duly corrected densities at some degrees above 

 the critical temperature are only slight, and probably due to the 

 admixture of not more than a two-hundredth of a milligram of 

 a non-coercible gas. This gas, if not air, perhaps originates 

 by the decomposition of some ether during the sealing of the 

 tube before the blowpipe. 



BOOKS AND PAMPHLETS RECEIVED. 

 Books. — Alembic Club Reprinls. No. 6 (Clay, Edinburgh).— Nature's 

 Method in the Evolution of Life. 1S54 (Unwin). — Climbing in the Rritish 

 Inle-i ; \V. R, H. Smith (Loncman*, 1894).— Tourist Guide lolheCoDtincnL : 

 N.E.. 1894 (30 Fleet Street). — Eiektro-chcmie Erste und Zweite Liefg; 

 Dr. W. 0»tw.ild (Leip7ie, Veit). — A Selection of Ph-tographs of Stars, Star 

 Clusters and Nebulae; Dr. J. Roberts (Universal Press).— The Country 

 Month by .Month, July, i8j4 : J. A. (>wen and Prof. Boulger (61i<$). — 

 Elementary Treatise on Natur.-il Philosophy, iith cdiiion : Prof. J. D. 

 Everett, i?04 (Klackie). — Repaitition de la Prcssion Atmospherique sur 

 I'Occan Atlantique Septentrional d'Aprirs les Observations de 1870 a 

 1885 ; par le Capitainc G. Rung, 1S94. — Returns of the Agricultural Sta- 

 tistics of British India and Native St.ite of Mysore. 1892-3 (Calcutta, 1894). 

 — Malaysian Spiders, Parts i, a, and 3 : T. and M. E. Workman (Belfast. 



1 3(14). 



Pa.mphlets. — Ebbc und Fluth in Luftmecrder Erde : Prof. Dr. I. Hann 

 (P.-)ctel, Berlin). — J >urnal of the Royal .\gricultural Society of England, 

 Vol. 5, Part 2(1894, Murray). — Pr tceedings of the Bath Natural History 

 Antiquarian Field Club. Vol. 8. No. 1 (Bath, 1894). — Transactions ofithe 

 Institute of Brewing, Nos. 7 8(J. S. Phillips). 



CONTENTS. PAGE 



A Laboratory for Physical and Chemical Research 217 

 The Histological Investigation of Disease. Hy A. 



A Kanthack .... 218 



Natal Astrology. By W. E. P 219 



Naval Engineering 220 



Our Book Shelf:— 



Ellis: " The Yoruba-speaking Peoples of (he Slave 

 Coast of West .\frica ; their Religion, Manners, 



Customs, Laws, Languages, &c." 221 



"A Handbook to the Study of Natural History, for 



the Use of Beginners" 221 



Middlcton .- " Surveying and .Surveying Instruments " 221 

 Letters to the Editor: — 



The I'h itography of the Spl.ash of a Drop. {Illiis-] 



traUil.)—R. S. Cole 222 



On the Spreading of Oil upon Water. — Miss Agnes 



Pockels .... 223 



Prof. Ostwald on English Chemists. — A. G. Bloxam 224 



7'tslacella /la.'ioliilca.—}. Lloyd-Bozward .... 234 

 On the Diselectrilication of Metals and other Bodies 



by Light. — Prof Oliver J. Lodge, F. R.S. . . . 22$ 



Absence of Hutictllics. — Delta 225 



The Settlement of the Epping Forest Question. By 



Prof, R. Meldola, F.R.S 22$ 



Notes 227 



Our Astronomical Column : — 



The First (Observation of Sun-spots 23O 



The Progress of \slronoinical Photography . . . 230 



Mr. Tebhutt's Observatory, New South Wales . 23I 



A New Spiral Nebula, {//luilraltd.) 831 



Twenty-five Years of Chemistry in Russia .... 23I 



The Landslip at Gohna, Garhwal. [IlluitraltJ.) . . 23I 



Science in the Magazines 234 



University and Bductional Intelligence 235 



Scientific Serials 235 



Societies and Academies 236 



Books and Pamphlets Received 24° 



1 



