96 



NA TURE 



'Mav 



1901 



forming minerals thus being but little differentiated. To over- 

 come this ditticulty, while preserving to the section the desirable 

 transparency, the author, by a simple addition to the petro- 

 logical microscope, sends the polarised ray twice through the 

 section. This is accomplished by means of an opaque illumin-' 

 ator, an arrangement furnished by many makers, consisting of an 

 attachment above the objective, containing a totally reflecting 

 prism illuminated by light received through a frontal aperture, 

 and transmitting the ray downwards through the objective on 

 the object being examined, from the surface of which it is reflected 

 again into the microscope. In the present application of the 

 illuminator to the petrological microscope a nicol is attached 

 over the aperture, and the ray totally retiected and transmitted 

 downwards within the objective is (sensibly) plane polarised. 

 Beneath the rock-section a small mirror of speculum metal or 

 silver is placed. The ray after its first passage through the 

 crystal under examination is reflected by this mirror, and the 

 incidence being nearly normal is again returned through the 

 crystal, thus traversing it twice before reaching the eye. It can 

 be demonstrated, with a double image prism and by colour ob- 

 servations on a plate of selenite overlapped upon itself, that the 

 loss of phase does not interfere with the accuracy of the method. 

 This mode of examination at once introduces discriminative 

 differences into the tints of many important substances, as the 

 monoclinic and triclinic felspars, quartz, &c., all former differ- 

 ences of retardation being, in fact, doubled in amount. — Prof. 

 Hugh Ryan read a paper on the synthesis of glucosides, and, 

 in conjunction with Mr. W. Sloan Mills, one on the synthesis 

 of galactosides. — Mr. R. J. Moss made some interesting experi- 

 ments with liquid air by means of the Hampson gas liquefying 

 apptratus. 



Paris. 

 Academy of Sciences, May 13. — M. Fouque in the chair. 

 — On a perfectly astatic galvanometer, by M. Lippmann. The 

 needle of the galvanometer described is mounted in such a way 

 that it can be placed in the plane of the magnetic meridian and 

 under the action of the current tends to move parallel to itself 

 Under these conditions the earth's field exerts no opposing force 

 to the action of the current, and the apparatus is perfectly 

 astatic. — On the theorems of Ilugoniot, the lemmas of M. 

 Hadamard, and the propagation of waves in viscous fluids, by 

 M. P. Duhem. — On the real integrals of differential equations 

 of the first order in the neighbourhood of a singular point, by 

 M. Henri Dulac. — On certain involutive lelations, by M. 

 Maurice Lelieuvre. — On a problem of d'Alembert, by M. F. 

 Siacci. — On an experiment in electrical oscillations, by M. H. 

 Pellat. — The permeability of nickel-steels in intense fields, 

 by M. Rene Paillot. Three classes were examined — irre- 

 versible steels, reversible steels, and steels containing small 

 quantities of chromium and manganese besides nickel. In 

 the first of these the magnetic permeability sensibly increased 

 in the intense fields ; in the second case, the reversible 

 steel, the permeability attained a value of I'lg for a field of 

 4000 C.G. S. units, and remained practically constant up to 

 30,000 units. — On the laws of outtlow of air in musical in- 

 struments, by M. Firmin Larroque. — On the aromatic organo- 

 niagnesium compounds, by MM. Tissier and Guignard. It is 

 shown that the halogen benzene derivatives react with magne- 

 sium in a manner exactly analogous with the halogen compound 

 of the fatty series. As examples of the generality of this 

 method, the preparation of triphenyl-carbinol, dimethylphenyl- 

 carbinol and diphenyl-ethylene are described. In all cases the 

 yields are nearly theoretical. — The ^decomposition of albumin- 

 oids into protoplasmides, by M. A. Etard. Decalcified bone, 

 submitted to a simple hydrolysis, gives three groups of sub- 

 stances : glycocoU, leucine and a little tyrosine ; a syrupy 

 material very soluble in methyl alcohol ; and a substance quite 

 insoluble in methyl alcohol. The last compound has been 

 analysed and is named bososteoplasmide. — Differences in the 

 constitution of the bile according to the age and fatty state of 

 the animal, by M. R. L. Craciunu. — On the phosphoric acid of 

 the soil, by M. Th. Schkesing, jun. An examination of the 

 amount of phosphates removable from certain soils by repeated 

 extraction with water. — On the composition of amblygonite, by 

 M. Henri Lasne. — Histological researches on the sporulation of 

 yeasts, by M. A. Guilliermond. At the moment of sporulation 

 there appears to be a sort of solution of the red grains contained 

 in the vacuoles, these bodies appearing to behave in some 

 respects as a reserve material. 



NO. 1647, VOL. 64] 



DIARY OF SOCIETIES. 



THURSDAY, May 25. 



RoVAl. Society, at 4.30.— On the Presence of a Glycolyiic Enzyme 

 in Muscle: Sir Lauder Brunton,F.R.S , and Herbert Rhottes.-On Nega- 

 tive After-images and their Relation to certain other Visual Phenomena : 

 S. Bidwell, F.R.S.— The Solar Activity, 1833-1900 : Dr. W. J. S. Lockyer. 

 — A Comparative Crystallographical Study of the Double Selenates of the 

 Series RoM(SeOj)o, 6H0O.— Sails in which M is vMagnesium : A. E. 

 Tutton, F.R.S.— dn the Intimate Structure of Crystals. Part V. Cubic 

 Crystals with Octahedral Cleavage : Prof. W. J. SoUas, F.R.S. 



Royal Institi;tion, at 3.— The Chemistry of Carbon : Prof J. Dewar, 

 F.R.S. 



FRIDAY, May 24. 



Royal Institution, at 9.— The Aims of the National Physical Labora- 

 tory: Dr. R. T. Glazebrook, F.R.S. 



SATURDAY, May 25. 



Royal Institution, at 3.— The Rise of Civilisation in Egypt : Prof. W. M , 

 Flinders Petrie. 



TUESDA Y, May 23. 



Royal Photographic Society, at 8.— (i) Practical Tricolour Photo- 

 graphy ; (2) The Optics of Tricolour Photography : E. How.itd Farmer. 



.\nthropological Institute, at 8.30.— Measurements of Crania I. om 

 the Fly River : J. Gray. — Anthropometrical and Craniological Notes 

 on the Eastern Papuans : C. G. Seligmann.— Remarks on the Present 

 State of our Knowledge of the Ethnology of British New Guinea : Prof. 

 A. C. Haddon. 



THURSDAY. May 30. 



Royal Institution, at 3.— The Chemistry of Carbon : Prof. J. Desvar, 

 F.R.S. 



Institution of Electrical Engineers (Society of Arts), at 8.— Annual 

 General Meeting. 



FRIDAY, May 31. 



Royal Institution, at 9.— With the Allies in China: A. H. Savage 

 Landor. 



Physical Society, at 5.— On a Model which imitates the Behaviour of 

 Dielectrics: Prof. Fleming, F.R.S., and A. W. Ashton.— <i) On the Re- 

 sistance of Dielectrics and the Effect of an Alternating Electromotive 

 Force on the Insulating Properties of India-rubber ; (2) Note on the 

 Electrification of Dielectrics by Mechanical Means : A. W. Ashton. 

 SATURDAY, June i. 



Royal Institution, at 3.— The Biological Characters of Epiphytic 

 Plants : Prof. J. B. Farmer, F.R.S. 



CONTENTS. PAGE 



Native Races as Imperial Problems. By E. 



Sidney Hartland 73 



Progress in the Coming Century 74 



Vertebrate Histogenesis 75 



Our Book Shelf:— 



" The Scientific Memoirs of Thoinas Henry Huxley, 



vol. iii." ... . 76 



Johnson: " Fact and Fable" 76 



AUbutt : " Science and Medieval Thought " .... 76 

 Letters to the Editor : — 



On a Form of Artificial Submarine Cable. ( IVilh 



Diagram.) Prof. A. Trowbridge 77 



Electro-chemistry. — Bertram Blount ; Dr. F. 



Mollwo Perkin 77 



Specimens ol .Kcidium birberidis.—l. Lewton Brain 77 

 The British Association Meeting. By Prof Magnus 



Maclean ... 78 



The Recent Total Solar Eclipse . . 79 



Recent Work of the U.S Weather Bureau ... 80 



A Canadian Geological Explorer .... 81 



Sir Courtenay Boyle, K.C.B. By R. T. G 82 



The National Antarctic Expedition 83 



Notes 86 



Our Astronomical Column :— 



New Variable Star 71 (1901) Auriga; 89 



Spectrum of i Puppis 89 



Definitive Orbit of Comet 1894 II. (Gale) 89 



The University of London 89 



The Language and Origin of the Basques. By 



A. C. H 90 



The Diagnosis of Plague. By Dr. E. Klein, F.R.S. 91 



University and Educational Intelligence ... 92 



Scientific Serials 92 



Societies and Academies 93 



Diary of Societies 96 



