320 



NATURE 



[December 20, 191 7 



implements found along with the plated articles consist 

 of iron spears, axes, adzes, hammers, ploughshares, 

 billhooks, and sickles, of the types found in settlements 

 ■elsewhere of the .same age, such as Hunsbury, near 

 Northampton, and the Lake Village at Glastonbury. 

 In addition to these there were also fetters and a chain 

 for a chain-gang of six, with six rings to put round 

 the neck. Similar bronze-plated iron articles have been 

 met with elsewhere.— R. L. Taylor : The effect of light 

 on solutions of bleaching powder. Experiments were 

 described in which solutions of bleaching powder, differ- 

 ing in concentration and prepared in different ways, 

 were exposed to diffused daylight and to intermittent 

 bright sunlight, while other similar solutions were kept 

 in the dark. Some of the experiments extended over 

 fifteen months. It was found that solutions exposed 

 to sunlight decomposed quite rapidly, those exposed to 

 •diffused daylight much morfe slowly, while dilute solu- 

 tions (i per cent.) kept in the dark remained quite 

 unaltered for the whole period of fifteen months. A 

 solution five times the strength of the latter, however, 

 •did undergo some decomposition, losing about 20 per 

 cent, of its available chlorine, even when kept in the 

 ■^ark. 



Dublin. 

 Qoyal Dublin Society, November 27.^ — Prof. Hugh 

 Ryan in the chair.— Dr. F. E. Hackett and R. J. 

 JFeeley : The polarisation of a Leclanch^ cell. The re- 

 covery of a Leclanch^ cell from polarisation can be 

 analysed into two parts, a rapid recovery and a slow 

 •(ireep towards the initials E.M.F. The period of rapid 

 recovery can be represented closely by an equation 

 similar to the equation for the decay of ionisation in a 

 gas. The recovery of a Weston cadmium cell from 

 short circuit for a brief interval seems also to obey the 

 «ame law. ■ The disappearance of polarisation is there- 

 fore mainly a bimolecular reaction. — Miss E. J. 

 Leonard : The genus Taenitis, with some notes on the 

 remaining Taenitidinae. The paper is an endeavour to 

 place Taenitis in its true phyletic position, and to find 

 out what relationship, if any, it bears to the other 

 genera classed with it, under the heading Taenitidinae. 

 Taenitis bears a strong external resemblance to Blech- 

 num, and this resemblance is further supported by 

 many points in its anatomy, such as glandular dermal 

 appendages, the venation of the leaf, and the presence 

 of a commisural vein underlving the sorus. Tapnitis 

 is therefore classed as a derivative form in the Blech- 

 noid series. Of the remaining genera, the only one 

 which shows definite relationship to Taenitis is Eschato- 

 grarrime. The others examined — Drymoglossum, Pal- 

 tonium, Hymenolepis — are widely divergent, probably 

 in accordance with their epiphytic habit. 



BOOKS RECEIVED: 



A Supplementary Memoir on British Resources of 

 Sands and Rocks used in Glass Manufacture, with 

 Notes on certain Refractory Materials. By Prof. G. H. 

 Boswell and others. Pp. 92. (London : Longmans 

 and Co.) 35. net. 



Telegraph Practice. By J. Lee. Pp. ix+102. 

 (London : Longmans and Co.) 2s. 6d. net. 



Studies in the History and Method of Science. 

 Edited by C. Singer. Pp. xiv-l-304. (Oxford: At the 

 Clarendon Press.) 21s. net. 



Meteorological Office. British and Magnetic Year 

 Book, iqi^. Part iii., Section 2. (London : Meteoro- 

 logical Oftice.) . I05. net. 



National Physical Laboratory. Notes on Screw 

 Gauges. By the Staff of the Gauge-Testing Depart- 



NO. 2512, VOL. 100] 



ment. Enlarged issue ii. November. (Teddington : 

 W. F. Parrott.) 2s. 6i. 



Cape Peninsula List of Serials. Being a Catalogue 

 of the Publications available for Consultation in the' 

 Libraries of the British Medical Association, etc. 

 Second edition. Pp. 95 + iv. (Cape Town: South 

 African Public Library.) 



DIARY OF SOCIETIES. 



THURSDAY, December 20. 

 Institution of Mining and Mei-allurgv, at 5.30.— A Neglected 

 Chemical Reaction and an Available Source of Potash : E. A. Ashcroft. 

 —Syphoning Gravel : J. Jervis Garrard. 

 Chemical Society, at 8.— V.icuum Balance Cases : B. Blount.— Spark- 

 I lengths in Hydrocarbon G.-ises and Vapours : R. Wright.— Studies of Dry- 

 ing Oils. I. The Properties of some Cerium Salts obtained from Drying 

 Oils : R. S. Morrell. — The Relation of Position Isomerism to Optical 

 Activity. XI. The Menthyl Alkyl Esters of Terephthalic Acid and its 

 I Nitro-derivatives : J. B. Cohen and H. S. de Pennington.— Diketo- 

 hydrindene. III. : A. K. Das and B. N. Ghosh.— Synthesis of Pyranole- 

 derivatives : S. C. Chatterji and 15. N. Ghosh.— Synthesis of 3 : 4- 

 Dihydroxyphenanthrene (Morphol)and of 3 : 4-Phenanthraquinone : G. 

 Barger. 



THURSDAY, December 27. 

 Royal Institution, at 3.— Magnets and the Magnetic Compass: Prof. 

 J. A. Fleming. 



SATURDAY, December 29. 

 Royal Institution, at 3.— Electricity and Electric Currents : Prof. J. A. 

 Fleming. 



CONTENTS. PAGE 



The Tuberculosis Problem 301 



Mathematical Puzzles 302 



Fossil Botany • ..... 303 



Our Bookshelf • • ' 303 



Letters to the Editor:— 



Ramsay Memorial Fund.— Lord Rayleigh, O.M., 

 F.R.S., Sir Hugh Bell, Bart., Lord Glen- 

 conner, Prof. J. N. Collie, F.R.S. .... 304 



The Beginnings of Porcelain in China.— Dr. R. 

 Laufer, H. W. Nichols; Dr. J. W. Mellor . 304 

 Magnetic and Electrical Observations at Sea, 

 [Illustrated.) By Dr. C. Chree, F.R. 8. .... 305 



Agricultural Education and Research in the United 

 States . ....... .308 



Dr. A. M. W. Downing, F.R.S. By Dr. A. C. D. 



Crommelin . . 308 



Notes ... 309 



Our Astronomical Column :— 



The Approaching Shower of January Meteors (Quad- 



rantids) . 3^3 



Observations of j3 Lyree ......... 313 



Radial Velocities of Star Clusters . . . ' 313 



Parallax of the Ring Nebula in Lyra ..... 313 



Aeronautics and Invention . 314 



The Peopling of Melanesia. By Sidney H. Ray . . 314 



Canadian Exploration . . 315 



Effects of Storage upon Coal . ... 3^5 



The Nitrogen Problem and the Work of the 

 Nitrogen Products Committee . ..... 316 



University and Educational Intelligence . ... 318 



Societies and Academies , . . . 319 



Books Received 320 



Diary of Societies . . .... 320 



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Advertisements and business letters to be addressed to the 

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Editorial Cornmunications to the Editor. 

 Telegraphic Address : Phusis, London. 

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