1 20 



NATURE 



[April 5, 191; 



displacement of the image measured by a micrometer 

 eyepiece. Densities can be indirectly determined by 

 this refractometer to the fifth docinoal figure with 

 great rapidity. — L. Abonnenc : The laws of flow of 

 liquids by drops in cylindrical tubes. Vaillant has 

 shown that when a liquid falls in drops from the 

 orifice of a cylindrical tube the weight of a drop 4s 

 a parabolic function of the frequency of fall. An 

 extension of these exf>eriments to tubes of less than 

 2 mm. external diameter is given.— P. Gaubert : The 

 rotatory power of liquid crystals.-— :A. Guiliiermond : 

 Vital observations of the chondriome of the flower of 

 the tulip. — C. Vincent : The forms of phosphorus in 

 Breton granitic soils. The amount of phosphorus 

 found in these soils will be underestimated if the 

 method of extraction by strong mineral acids is used 

 in the analysis. The organic phosphorus present in 

 the humus may amount to 50 per cent, of the total 

 phosphorus, and this explains the effects of liming 

 these soils. From these results a rational method 

 of manuring is deduced. — M. Herlant : The variations 

 of the volume of the nucleus of the <t^^ rendered 

 active by butyric acid. — J. Effront : Achrodextrinase. 

 Certain species of B. me^scnf mews, cultivated in a nitro- 

 genous medium, secrete a diastase liquefying starch. 

 The hydrolysis of starch by this ferment was studied 

 in comparative exf)eriments with malt extriict, 

 ptyalin, and pancreatic amylase. The behaviour of 

 the mesenteric amylase was distinctive, and the name 

 achrodextrinase is proposed for it. Some practical 

 applications in the textile industry axid in the laundry 

 are suggested. — M. Marage : Arterial pressure in cases 

 of deafness caused by shell shock. Eighty-two per 

 cent, of the cases examined showed arterial pressure 

 above the normal, and insomnia generally accom- 

 panied the hypertension. The pains in the head, 

 usual in these cases, do not appear to be connected 

 with the arterial pressure. The best treatment Is 

 d'Arsonvalisation. — M. Lautier : The treatment of cases 

 of war-deafness. The Marage method is easy to 

 3pply» generally useful, and never harmful. Its 

 general employment in these cases is strongly re- 

 commended. — M. Rappin : Antituberculous vaccina- 

 tion. 



BOOKS RECEIVED. 



British Wild Flowers : Their Haunts and Associa- 

 tions. By W. Graveson. Pp. xv + 320 + plates 1. 

 (London : Headley Bros.) 75. 6d. net. 



The Tutorial Chemistry. By Prof. G. H. Bailey. 

 Part ii., Metals and Physical Chemistry. Third 

 edition. Pp. viii + 460. (London: University Tutorial 

 Press, Ltd.) 45. 6d. 



M^t^orologie du Bresil. By C. M. Delgado de 

 Carvalho. Pp. xix + 525. (London: John Bale, Ltd.) 

 25s. net. 



Chemistry for Beginners. By C. T. Kingzett. 

 Pp. vi+io6. (London: Bailliere,' Tindall, and Cox.) 

 25. 6d. net. 



Contributions to Embryology. Vol. iv. Nos. 10, 

 II, 12, 13. Pp. io6-i-plates iv. (Washington: Car- 

 negie Institution.) 



Carnegie Institution of Washine'ton. Year book, 

 No. 15. Pp. xii -1-404. (Washington: Carnegie 

 Institution.) 



Studies on the Variation, Distribution, and Evolu- 

 tion of the Genus Partula. The Species inhabiting 

 Tahiti. Bv Prof. H. E. Crampton. Pp. 311 + 34 

 plates. (Washinerton : Carnegie Institution.) 



X Rays. By Dr G. W. C. Kaye. Second edition, 

 with illustrations. Pp. xxi -1-285.' (London: Long- 

 mans and Co.) qs. net. 



Electrical Laboratory Course. Bv Dr. M. Maclean. 

 Pp. 120. (London : Blackie and Son, Ltd.) 25. net. 

 NO. 2475, VOL. 99] 



A Short System of QualitEitive Analysis. By Dr. 

 R. M. Caven. Pp. viii+162. (London: Blackie and 

 Son, Ltd.) 2S. 



The Chemists' Year Book. Edited by F. W. Atack, 

 assisted by L. Whinyates. 2 vols. Pp. 1030 

 (London and Manchester : Sherratt and Hughes.) 



Studies in Insect Life, and other Essays. By Dr. 

 A. E. Shipley. Pp. ix-t-338. (London : T. Fisher 

 Unwin, Ltd.) los. 6d. net 



An Introduction to a Biology, and other Pa}>ers. 

 By A. D. Darbishire. Pp. xviii-f-29i. (London: 

 Cassell and Co., Ltd.) 75. 6d. net. 



The Manufacture of Sulphuric Acid and Alkali, witli 

 the Collateral Branches. By Prof. G. Lunge. Fourth 

 edition. Supplement to Vol. i.. Sulphuric and Nitric 

 Acid. Pp. xii -1-347. (London : Gurney and Jackson.) 

 155. net. 



Bill's School and Mine : a Collection of Essays ©n 

 Education. By W. S. Franklin. Second edition. 

 Pp. vii-l-io2. (South Bethlehem, Pa.: Franklin, 

 McNutt, and Charles.) i dollar. 



Geology: Physical and Historical. By Prof. H. F. 

 Cleland. Pp. 718. (New York: American Book Co.) 

 3.50 dollars. 



DIARY OF SOCIETIES. 



THURSDAY, April 12. 

 Institution ok Electrical En-gineers, ai 6. — Wayleaves : C. Vernier. 

 Optical Society, at 8. — Light Filters fir Eye Protection : L. C. Martin 

 — .Accuracy of Ob-ervation and Precision in Measurement : Dr. G. A 

 Carse.— Some Methods of Analy-iii jr Lens Systems : S. D. Chalmer«:. — A 

 .Simple Proof of the Expresion for the Focal Power of a Thick Lens ■ 

 C. Cochrane. 



FRIDAY, April 13. 

 Royal Astronomical Society, at 5. 



CONTENTS. PAGE 



The Teaching of Physiology. By Prof. W. M. 



Bayliss, F.R.S. loi 



Some Mathematical Text-books 102 



Our Bookshelf . 103 



Letters to the Editor: — 



British Optical Science. — ^James Weir French . . 105 



Floating Earths. — Dr. Cecil H. Desch . . . 104 

 Gravitation and Thermodxnaniics. — Sir Oliver 



Lodge, F.R.S. ; Dr. George W. Todd 104 

 Thermionic Detecors in Wi>eless Telegraphy and 



Telephony. {With Diagrams.^ . . ... loq 



The Indian Science Congress. By F. L. U. . . 108 



Notes 109 



Our Astronomical Column :— 



Comet 1017a (Mellish) II2 



D' Arrest's Periodic Comet 112 



Bright Meteors in March 112 



Photographs of Jupiter H2 



The Institution of Naval Architects .113 



British Filter-Papers 114 



Compulsory Continuation Classes . . 114 

 Recent Progress in Spectroscopy. By Prof. E. P. 



Lewis 115 



University and Educational Intelligence ... .118 



Societies and Academies 118 



Books Received 120 



Diary of Societies 12b 



Editorial and Publishing Offices : 



MACMILLAN AND CO., Ltd., 



ST. MARTIN'S STREET, LONDON, W.C. 2 



Advertisements and business letters to be addressed to the 

 Publishers. 



Editorial Communications to the Editor. 

 Telegraphic Address : Phusis, London. 

 Telephone Number : Gerrard 8830. 



