December 2, 1920] 



NATURE 



459 



depends is not valid for the X-rays from a Coolidge 

 tube under a potential of 60,000 volts or higher, and 

 the use of this instrument should be confined to the 

 measurement of X-rays of medium or low penetra- 

 tion such as those utilised in medical radiography or 

 superficial radio-therapy. — L. and E. Bloch : The 

 spark spectra of mercury, copper, zinc, and thallium 

 in the extreme ultra-violet. The measurements were 

 made with a prism spectrograph, and the wavi-- 

 lengths given are based on Lyman's data obtained 

 with a grating. New lines are given for all four 

 metals.— C. Ravean : The determination of the number 

 of independent components. The rule of M. Dubreuil ; 

 the action of water on a mixture of salts. — J. B. 

 ScDdcreni : The catalytic dehydration of fermentation 

 amyl alcohol. Catalysis by aluminium silicate at 

 340° to 350° C. gives a mixture of three amylenes, 

 and the proportion in which these are present depends 

 on the length of time the catalyst has been in use. 

 The first litre of amylenes collected contained 93 per 

 cent, of amylene soluble in diluted sulphuric acid, 

 the third litre only 75 per cent. — R. Cornnbert : The 

 spectrochemical study of the a-allyl- and o-allylmethvl- 

 cycJohexanones. — L. Daparc and G. Favfe : The 

 deposit of oolitic iron ore at Ain-Babouche (Algeria). 

 — H. Jamellc : The katoka, a Madagascan tree with 

 edible seeds. The tree is a new species of the genus 

 Treculia, and is named Treculia Perrieri. It is 

 abundant in the west of Madagascar and produces a 

 good wood and edible seeds. The latter are consumed 

 bv the natives as food, and have been imported into 

 France for the extraction of (heir oil. — H. Bouyf^ues : 

 The terminal meristem of the stem and its division 

 into regions.—P. LcMge : Evaporometers and the 

 motion of fluids through membranes. — A. Damicns : 

 The bromine and chlorine existing normallv in animal 

 tissues. Bromine was found in all the organs 

 examined, except in two or three cases where the 

 quantities of rnaterial available were too small. The 

 ratio of bromine to chlorine in the organs of anv 

 given animal is sensiblv constant, and is of the order 

 0001 to 0002.— I.. Mercler: Variation in the number 

 of the fibres of the longitudinal vibrator muscles in 

 Chi'rfndrnmia hirta. Loss of the power of flight. — 

 C._ tuHn ,->nd A. Robert : Orcanocenesis in the blasto- 

 zoites of Peronhorn.— T. Tommaiina : Remarks on the 

 note hv M._ Louis Besson on the relation between the 

 meteorolocical elements and the number of deaths 

 hv inflammatory diseases of the respiratory organs at 

 Paris. 



Books Received. 



The Birds of the British Isles and their Eggs. By 

 T. A. Coward. Second Scries : Comprising Families 

 Anatidx to Tetraonidae. Pp. vii+376+i.<;q plates. 

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Consid<^rations sur I'Efre Vivant. Bv C. Janet. 

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The Annual of the British School at Athens. 

 No. xxiii., .Session loiR-rq. Pp. xvi + 260+xvi plates. 

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.Anxietv Hvsteria : Modern Views on some Neuroses. 

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 IJ4. (London: H. K. I.ewi» and Co., Ltd.) +i.6d. 

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From the ITnronscIous to the Conscious. By 0. 

 Gelcy. Translated bv Stanley de Brnth. Po. xxviii + 

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 M. net. 



! iinrtional Mental Illnesses nml ihr. tntnr>!«r.<<n<|. 

 NO. 2666, VOL. 106] 



ence of the Sympathetic and Central Nervous Systems 

 in Relation to the Psychoneuroses. By Dr. R. G. 

 Rows and Dr. D. Orr. Pp. 63. (Edinburgh and 

 London : Oliver and Boyd.) 3s. 6d. 



Ather und Relativitats-Theorie. Rede gehalten am 

 ^ Mai 1920 an der Reichs-Universitiits zu Leiden. 

 .By A. Einstein. Pp. 15. (Berlin: J. Springer.) 

 2.80 marks. 



The Progress to Geography. By Dr. R. Wilson. 

 Stage I : Pictures and Conversations. Pp. 144. 

 2s. 6d. Stage 2 : More Pictures and Conversations. 

 Pp. 176. 3.?. (London : Macmillan and Co.. Ltd.) 



Ministry of Health, .\nnual Report of the Chief 

 Medical Officer, 1919-20. (Cmd. 978.) Pp. 393. 

 (London : H.M. Stationery Office.) 3s. 6d. net. 



Memoirs of the Geological Survey. Special Reports 

 on the Mineral Resources of Great Britain. Vol. vii. : 

 Mineral Oil, Kimmeridge Oil-Shale, Lignites, Jets, 

 Cannel Coals, Natural Gas. By Sir A. Strahan. 

 Second edition. Pp. iv+i2S. (London: E. Stanford, 

 Ltd. : Southampton : Ordnance Survey Office.) 55. 

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Productive Soils. The Fundamentals of Successful 

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 By W. \V. Weir. Pp. xvi + 398. (Philadelphia and 

 London : J. B. Lippincott Co.) loi. 6d. net. 



■An Introduction to the Structure and Reoroduction 

 of Plants. By Prof. F. E. Fritch and Dr. E. J. 

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British Plants : Their Biology and Ecology. By 

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Public Health Chemical .Analysis. By R. C. 

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Hydraulics with Working Tables. By E. S. Bel- 

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Practical Physiological Chemistry. Bv S. W. Cole. 

 .Sixth edition. Pp. xvi + 405. (Cambridge : W. HefTer 

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Collected Papers on the Psychology of Phantasy. 

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The Origin of Man and of his Superstitions. By 

 C. Read. Pp. xii + 350. (Cambridge: at the Univer- 

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Maryland Geological Survey. Cambrian and Ordo- 

 vician. Pp. 424+lviii plates. (Baltimore : Johns 

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Report on the Danish Oceanographical Expeditions, 

 1908-1910, to the Mediterranean and Adjacent Seas. 

 By Dr. iohs. Schmidt. No. 6. Vol. ii. : Biology. 

 Pp. 140+ 1 10. (Copenhagen: A. F. H0st and Son.) 



La Chimie et la Guerre. Science et Avenir. By 

 Prof. C. Moureu. Pp. iii+384. (Paris: Masson et 

 Cie.) 10 francs. 



Dialer of Socle* ies. 



TUURSUAr, Durtuitii 1. 



KoTAL .\rROYAiTKAi. Hoc'irTT (»t Roy»l Hoctety of Art«). at 5.— 

 M>Jnr O. H. 8<-atl : Alr>blp Pilotiii(.— Flirht-Urutcnut F. L. C. 

 Butchpr : Airnhip Moormif. 



CKiLD'tiTiiiT HtMirrt (at Hnjrkl RanlUrT Inititntr), «t 6.— Dr. W. 

 Brown: Thr V»lui> vt Huirfff^ntiDn in Kdncntion. 



CaiMirii IXxiKTT at u -Hir i'rafull* C. My ' Varjrlar Tileaer 

 of I'lttlnum X ■■ ' to MrnwpUnlo Rsdirlra.— H. F.. Col: 



Tk* Inflnrnor nt on th« vrluoilr of cwrtain Rractiooa. 



»'«rt II. Tn, • r*«elMt«. A T«t of tb* Radlatloa 



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