72 



NATURE 



[May 2 1, 1903 



the other five ; and a model of a ring having a cross-bar 

 or stud, the surface of which was divided into eight sections, 

 each of which marched with the other seven. In the case 

 of maps on such surfaces, at least six and eight colours 

 would be required in the respective cases.— Dr. Watson 

 read a note on the construction and attachment of galvano- 

 meter mirrors. It has often been pointed out, notably by 

 Lord Rayleigh and Prof. Threlfall, that it is better to 

 increase the sensitiveness of galvanometers and similar 

 instruments by improving the optical system, rather than 

 by pushing the electrical sensitiveness to extreme limits. 

 When working with ordinary silver on glass mirrors 

 difficulties arise in connection with the attachment of the 

 fibre and the fact that it is necessary to use a varnish, which 

 in all cases produces distortion. These difficulties have 

 been overcome by using quartz instead of glass, and 

 platinum instead of silver. • 



Mathematical Society, May 14. — Prof. H. Lamb, presi- 

 dent, in the chair. — Lieut.-Colonel A. Cunningham 



announced the discovery of seven new factors of Fermat's 

 numbers (2- ', viz. when n is 9, the factor 2'°. 37+1 ; when 

 n is II, the factors 2^^.3.13+1 and 2^.7.17+1 ; when n is 

 12, the factors 2'*. 397+1 and 2"'.7.i39+i; when n is 18, 

 the factor 2^°.i3+i ; when n is 38, the factor 2*^3+1. In 

 the cases of 9, 12, 18, the factors were discovered by Mr. 

 A. E. Western ; in the case of 11, by Lieut.-Colonel Cunning- 

 ham ; in the case of 38, jointly by collaboration of these 

 authors with Rev. J. Cullen. — Dr. H. F. Baker com- 

 municated a series of notes : — (i) On the definiteness of 

 quadratic forms with imaginary coefficients ; (2) On a 

 certain form of logical argument which occurs in the proofs 

 of several fundamental theorems of pure mathematics ; (3) 

 On the summation of Neumann's series representing a 

 potential determined by boundary values ; (4) On the form- 

 ation of the variant equation in the theory of differential 

 equations ; (5) On some points in the theory of continuous 

 groups. — The following papers were communicated : — Mrs. 

 Youngr, The surface representing all right-angled spherical 

 triangles. — Mr. W. H. Bussey, Generational relations de- 

 fining an abstract simple group of order 32736. — Mr. W. H. 

 Young:, (i) On skew surfaces contained in a linear con- 

 gruence ; (2) On closed sets of points and Cantor's numbers. 

 In the last of these papers methods and results obtained by 

 the author in a previous paper on the theory of sets of 

 intervals are applied to the theory of linear sets of points. 

 The theory of the higher transfinite numbers is avoided, 

 but the transition to these numbers is shown to arise 

 naturally, and a short account is given of the most recent 

 work on this subject. 



New South Wales. 

 Linnean Society, March 25. — Mr. J. H. Maiden, presi- 

 dent, in the chair.— The president delivered the annual 

 address, which was devoted chiefly to the consideration of 

 the principles of botanical nomenclature. — The newly-elected 

 president. Dr. T. Storie Dixson, then took the chair, and 

 the following papers were read : — A monograph of the 

 Australian Membracidae, by Dr. F. W. Coding'. In study- 

 ing this group, twelve genera, represented by thirty-five 

 species, have been recognised. — Revision of Australian 

 Lepidoptera, by Dr. A. Jefferis Turner. Under the above 

 heading the author hopes to publish a series of papers deal- 

 ing with the different families as time and opportunity 

 permit. This first instalment treats of the Notodontidae 

 and Hyponomeutidae. 



DIARY OF SOCIETIES^ 



THURSDAY, May 21. 



Royal Institution, at 5.— Proteid-Digestion in Plants: Prof. S. H. 

 Vines, F.R.S. 



Institution of Mining and Metallurgy, at 8. — Diamond Drilling in 

 West Africa : J. N. Justice.— On the Occurrence of Mica in Brazil, and 

 on its Preparation for the Market : H. Kilburn Scott.— Analytical Work 

 in Connection with the Cyanide Prpcess : J. E. Clennell.— Notes on the 

 Treatment of Gold Slimes in Venezuela: Leslie Symonds.— Notes on 

 Cupriferous Cyanide Solutions : H. A. Barker.— Notes on Chorolque 

 Tin Mines and Alluvial Deposits, Bolivia : M. Roberts. 

 J' RID A Y, May 22. 



Royal Institution, at 9.- Dictionaries: Dr. J. A. H. Murray. 



Physical Society, at 5.— Exhibition of Nernst Lamps, showing their 

 Development from the Experimental Form up to the most Recent Types : 

 J. Stottner.— Exhibition of a Diagram of Single-piece Lenses: T. H. 

 Blakesley.- On an Instrument for Measuring the Lateral Contraction 

 of Tie-Bars, and on the Determination of Poisson's Ratio : J. Morrow. 



MONDAY, May 25. 



Linnean Society, at 3.— Anniversary Meeting. 



Society of Chemical Industry, at 8.— (i) Neatsfoot Oil; (2I The 



Nitric Acid Test for Cotton Seed Oil : J. H. Coste and E. T. Shelbourn. 



TUESDAY, M\Y 16. 



Roval Institution, at 5.— The Work of Ice as a Geological Agent: 

 Prof. E. J. Garwood. 



Zoological Society, at 8.30.— On the present State of Knowledge as to 

 the Inheritance of Colour in Fancy Rats and Mice : W. Bateson, F.R.S. 

 — List of the Batrachians and Reptiles collected by M. A. Robert at 

 Chapada, Matto Grosso (Percy Sladen Expedition to Central Brazil): 

 G. A. Boulenger, F.R.S. — Note on some Bulimulidae from Matto Grosso 

 (Percy Sladen Expedition to Central Brazil) : Edgar A. Smith. 



Epidemiological Society, at 8.30. — The Etiology of Leprosy: Tonathan 

 Hutchinson, F.R.S. 



WEDNESDA Y, May 27. 



Geological Society, at 8.— An Experiment in Mountain-Building: 

 Lord Avebury, P.C, F.R.S.— (i) The Toarcian of Bredon Hill, and a 

 Comparison with Deposits Elsewhere ; (2) Two Toarcian Ammonites : 

 Sydney S. Buckman. 



THURSDA K, May 28. 



Royal Society, at 4.^0 — Probable /'a;>?r.f:— On the Bending of Waves 

 round a Spherical Obstacle: Lord Rayleigh, O.M., F.R.S. — Sur la 

 Diffraction des Ondes Electriques a propos d'un Article de M. Mac- 

 donald: Prof. H. Poincare, For.Mem.R.S — An Analysis of the 

 Results from the Kew Magnetographs on Quiet Days during the Eleven 

 Years 1890-1900, with a Discussion of Certain Phenomena in the 

 Absolute Observations: Dr. C. Chree, F.R S.— On the Theory of 

 Refraction in Gases : G. W. Walker.— Researches on Tetanus : Prof. 

 Hans Meyer and Dr. F. Ransom.— The Hydrolysis of Fats in vitro by 

 Means of Steapsin : Dr. J. Lewkowltsch and Dr. J. J. R. Macleod. 



Royal Institution, at 5— Electric Resonance and Wireless Telegraphy : 

 Prof. J. A. Fleming, F.R.S. 



Institution of Electrical Engineers, at s-— Annual General 

 Meeting. 



FRIDA Y, May 29 



Royal Institution, at 9.— The Progress of Oceanography: Prince of 

 Monaco. 



SATURDAY, May 30. 



Royal Institution, at 3.— The " De Magnete " and its Author : Prof. 

 S. P. Thompson, F.R.S. 



CONTENTS. PAGE 



The Principles of Disease. By T. C. A 49 



Zoology for Artists 50 



Hindu Chemistry. By T. K. R 51 



Our Book Shelf:— 



Hall: "The Soil: an Introduction to the Scientific 



Study of the Growth of Crops." — R. W 52 



Hooper and Wells : " Electrical Problems for Engineer- 

 ing Students." — M. S 52 



Dixon : " Open-air Studies in Bird Life ; Sketches of 



British Birds in their Haunts." — R. L 52 



Verrill : " The Bermuda Islands " 53 



Ozard : "La Pratique des Fermentations industrielles " 53 

 Letters to the Editor :— 



Psychophysical Interaction. — Sir Oliver Lodge, 



F.R.S. ; «:.\.7r.)/ 53 



"Red Rain" and the Dust Storm of February 22. — 



Dr. T. E. Thorpe, C.B., F.R.S 53 



The Undistorted Cylindrical Wave. — Oliver Heavi- 



side, F.R.S 54 



Seismometry and Geite.— Dr. C. Chree, F.R.S. . . . 55 

 Photograph of Oscillatory Electric Spark. {Illustrated. ) 



C. J. Watson 56 



Our Rainfall in Relation to Bitickner's Cycle.— Alex. 



B.|,MacDowall 56 



The Propagation of Phthisis. — Rev. Edmund 



McClure 56 



Tanganyika. {Illustrated.) ByJ. W. J 56 



Enlargement of the Kew Herbarium. By W. 



Botting Hemsley, F.R.S 58 



The South African Association 59 



The Royal Society Conversazione 59 



Cooperation in Astronomy. By Prof. Edward C. 



Pickering 61 



The Royal Visit to Glasgow. By G. A. G 63 



Notes 64 



Our Astronomical Column : — 



Nova Geminorum 68 



Parallax of the Binary System 5 Equulei 69 



A Regulating or Recording Thermometer. {Ilhis- 



trated.) By H. S. Allen 69 



University and Educational Intelligence 70 



Societies and Academies. {Illustrated.) 71 



Diary of Societies 72 



NO. 175 1, VOL. 68] 



