090 



NATURE 



[February 17, 19 1( 



four times as miich food energy. Even in the yield 

 of flesh meat the advantage is on the side of tillage. 

 More stock can be fed and more meat produced by 

 tillage. This is particularly shown in the case of pig 

 meat. The produce of an acre of land provides, as 

 pork or bacon, nearly five times as much protein and 

 seven times as much food energy as if the land were 

 used for grazing sheep or cattle. 



W. H. Thompson. 



HARVARD CONTRIBUTIONS TO 

 PHYSICS. 

 \70L. II. of "Contributions from the Jefferson Phys- 

 • ical Laboratory of Harvard" consists of reprints 

 of eighteen papers which have appeared in the Physical 

 Review and elsewhere during the years 1913-14. The 

 research work which these papers represents was 

 largely aided by the Coolidge and other funds for 

 original research. Dr. Bridgman's high-pressure 

 work occupies a large share of the volume. We have 

 already noticed in these columns his paper on the 

 technique of high-pressure experimenting. From his 

 other papers in the present volume it gcems now clear 

 that the melting points of solids continue to rise as 

 the pressure is increased to 12,000 kilos, per sq. cm. 

 at a rate which shows no sign of the existence of 

 maximum melting points or of any critical points in 

 the melting-point curves. Of the late Prof. B. O. 

 Peirce's work on the magnetisation of short cylinders 

 we gave an account some time ago. Prof. H. C. 

 Hayes shows that a rate-flow meter for fluids depend- 

 ing on the difference of pressure at the centre and 

 side of a vortex can be constructed to give results 

 correct to within 15 per cent. Mr. J. Coulson de- 

 scribes an apparatus for reproducing and measuring 

 very short intervals of time depending on the difference 

 of time an elastic wave takes to pass from a point 

 near the middle of a rod to the two ends. Prof. 

 Lyman has investigated the arc and spark spectra of 

 mercury in the region from A=i87o to 1270, and has 

 found that the positions of the lines do not agree with 

 the predictions of Hughes from photo-electric data. 

 In the theoretical field, Prof. Hall shows that the 

 phenomena of thermo-electricity seem to be due to free 

 electrons, but that electric conduction seems to a large 

 extent independent of them. Prof. Webster concludes 

 that the phenomena of radiation, of optics, and of 

 photo-electricity can be explained, without discarding 

 the classical dynamics, by the aid of the Parson mag- 

 neton — a ring- of electrons of diameter one-tenth that 

 of a hydrogen atom moving round its axis with the 

 speed of light. From these short notes it will be seen 

 that the volume constitutes a record of research of 

 which any university may be proud. 



FORTHCOMING BOOKS OF SCIENCE. 

 Agriculture. 



John Bale, Sons, and Danielsson, Ltd.— Green 

 Manures and Manuring in the Tropics, including an 

 Account of the Economic Value of Leguminosae as 

 Sources of Foodstuffs, Vegetable Oils, Drugs, etc.," 

 P. de Sornay, translated by F. W. Durlacher. 



Anthropology and Archeology. 

 John Lane. — The Magic of Malaya, C. W. Harrison. 

 Longmans and Co.— The Folk-Element in Hindu 

 Culture : a Contribution to Socio-Religious Studies in 

 Hindu Folk Institutions, Benoy Kumar Sarkar. Mac- 

 millan and Co., Ltd. — The Tribes and Castes of the 

 Central Provinces of India, R. V. Russell, 

 assisted by Rai Bahadur Hira Lai, four vols., 

 illustrated. The Medici Society, Ltd.— Central Amer- 



NO. 2416, VOL. 96] 



ican and West Indian Archaeology, T. A. Joyce, 

 illustrated ("Handbooks to Ancient Civilisations"), 

 The Oxford University Press. — Miscellaneous Baby- 

 lonian Inscriptions, Prof. A. T. Clay; Ob- 

 servations on the Mussulmauns of India, Mrs. 

 Meer Hassan Ali, edited, with introduction, by 

 W. Crooke; The Beginnings of Buddhist Art, 

 A. Foucher, translated by L. A. and F. W. 

 Thomas ; Origin and Meaning of some Funda- 

 mental Earth Structures, C. P. Berkey; Contributions 

 to the Ethnology of the Salish Tribes, J. A. Teit; The 

 Drama of Savage Peoples, Dr. L. Havemeyer. Kegan 

 Paul and Co., Ltd.— Earliest Man, F. W. H. Migeod. 



Biology. 



F. Alcan (Pari^).— L'Evolution des Plantes, N. 

 Bernard. John Bale, Sons, and Danielsson, Ltd.— 

 The Animal Parasites of Man, Dr. H. B. Fantham, 

 Prof. J. W. W. Stephens, and Prof. F. V. Theobald, 

 partly adapted from Dr. Max Braun's " Die Tierischen 

 Parasiten des Menschen " (fourth edition, 1908), and 

 an appendix by Dr. O. Siefert. The Cambridge Uni- 

 versity Press. — The Evolution of Reptiles, S. W . 

 Williston ; The Problem of Individuality in Organisms, 

 C, M. Child ; The Living Cycads, C. j'. Chamberlain ; 

 Mechanics of Delayed Germination in Seeds, W. 

 Crocker; The Problem of Fertilization, F. R. Lill'w 

 ("University of Chicago Science Series.") J. M. Dot! 

 and Sons, Ltd. — Name this Flower, Prof. G. Bonnier, 

 translated and edited by Prof. Boulger, illustrated ; The 

 Rambles of a Canadian Naturalist, S. T. Wood, illus- 

 trated. C.H. Kelly. — British Fungi, and How to Identify 

 Them, J. H. Crabtree. Longmans and Co.— British 

 Birds, written and illustrated by A. Thorburn, 4 vols., 

 vols. iii. and iv ; South African Botany, F. W. Storey 

 and K. M. Wright. John Murray. — Vegetable Fibres, 

 Dr. E.^ GoukUng ; The Study of Animal Life, Prof. ■ 

 J. A. Thomson, new edition, illustrated. Tlte Univer- 

 sity Tutorial Press, Ltd. — Practical Botany, Dr. F. 

 Cavers, new edition. Whittaker and Co. — Some Re- 

 cent Researches in Plant Physiology, Dr. W. R. G. 

 Atkins. John Wiley and Sons, Inc. {Ne-jj York), and 

 Chapman and Hall, Ltd. — Laboratory Manual of 

 General Microbiology, of Bacteriology, Hygiene, and 

 Pathology, W. Giltner ; Seeding and' Planting- in ihc 

 Practice of Forestry, J. W. Toumey; Landscape Gar- 

 dening as Applied to Home Decoration, new edition, 

 illustrated. 



Chemistry. 

 F. Alcan (Paris). — Le Radium, Prof. F. Soddy, 

 French translation. The Cambridge University 

 Press. — Food Poisoning, E. O. Jordan ; The 

 Development of a New System of Organic 

 Chemistry, based on Dissociation Concepts, J. U. : 

 Nef, with the co-operation of J. W. E. Glatt- 

 feld (" University of Chicago Science Series "). Gurney 

 and Jackson. — Coal-Tar and Ammonia, Prof. Lunge 

 (fifth) thoroughly revised and enlarged edition, three 

 parts. Crosby Lockwood and Son. — Industrial 

 Gases : Including the Liquefaction of Gases, Dr. G. .; 

 Martin, J. M. Scholer, E. Jobling, H. S. Redgrove, ^' 

 E. A. Dancaster, and F. B. Gatehouse ; The Minor 

 Elements : their Occurrence and Industrial Uses, S. J. I 

 Johnstone ("Manuals of Chemical Technology"). ' 

 Longmans and Co. — A System of Physical Chemistry, ,^ 

 Prof. W. C. McC. Lewis, 2 vols., with diagrams ■ 

 ("Text-books of Physical Chemistry"); The Respira- 

 tory Exchange of Animals and Man, Prof. A. Krogh 

 (" Monographs on Biochemistry "). Macmillan and » 

 Co., Ltd. — Donington's Class-Book of Chemistry, 

 part iv., The Metals. Methiien and Co., Ltd. — A ^ 

 Senior Experimental Chemistry, Drs. A. E. Dunstan | 

 and F. B. Thole, with diagrams ("Textbooks of ^ 

 Science "). The Oxford University Press.— Changes * 



