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exhibit a rather wide variation, which, however, is believed to be fortuitous; so that the mean value should be much more accurate. The mean of the eight values gives R=3.72 × 103, whereas the number given by the gas equation is R=3711 x 103 in the same units.

The fact that the value of the gas constant can be deduced in this way from purely electrical measurements must be regarded as a remarkable confirmation of the general position. The results of these experiments, and of others of a similar nature which I have not time to describe, show not only that the velocities of the electrons are distributed about the average value in accordance with Maxwell's law, but also that the emitted electrons are kinetically identical with the molecules of a hypothetical gas of equal molecular weight at the temperature of the hot metal. The experiments referred to formed the first direct experimental demonstration of the truth of Maxwell's law of distribution of velocities, and, although many of the consequences of this law have been made visible by the beautiful experiments of Perrin on the Brownian movement, I believe that they still furnish the most direct experimental verification of its truth. Quite recently a number of experimenters have called in question the general position which I have taken as to the nature of the process of electron emission from hot bodies, and have asserted that this effect is caused by chemical action between the hot solid and traces of contaminants, usually supposed to be gaseous, which have access to it. Whilst I feel that the value of the evidence in favour of the latter hypothesis has, generally speaking, been greatly over-estimated, it would take too long to discuss this question with the completeness which it demands. I shall therefore content myself with directing your attention to some experiments with tungsten filaments which prove that only an insignificant fraction, if any, of the emission from this substance can be attributed to chemical action.

Tungsten is peculiarly suited to these experiments on account of its great refractoriness. It can be heated in a vacuum for considerable periods at temperatures so high that all known impurities are volatilised out of it. The preliminary treatment of the experimental lamps furnishes some novel features which may prove of interest. The ductile tungsten filaments are electrically welded to the supporting leading wires in an atmosphere of hydrogen. After mounting, the lamps are exhausted in a vacuum furnace (with an external air pressure of about 1 cm.) at 550-600° C. for about twenty-four hours, until the evolution of gas becomes very small. A Gaede pump is used for the internal exhaust at first, and, later on, liquid air and charcoal in addition. In the final stages the tungsten is glowed at about 3000° absolute, and, for the best results, the anode is heated by subjecting it to an intense electron bombardment from the hot wire. The conditions as to freedom from gaseous contamination which have been attained in this way are far superior to those which result from any other method of treatment.

With lamps thus prepared I have carried out simultaneous measurements of the rate of emission of electrons on one hand, and either of the variation of the pressure of the gas present or of the rate of loss of matter by the filament on the other. Particular experiments have led to the following numbers :

(1) For each molecule of gas given off the number of electrons emitted by the filament may be as high as 260,000,000.

(2) At each impact of a gas molecule with the filament 15,000 electrons would have to be emitted, and (3) Each atom of tungsten which disappears from

the filament would have to cause the emission of 984,000 electrons.

The magnitude of these numbers entirely precludes the possibility that chemical action plays any signifi cant part in this emission. Again, the mass of the electrons lost by a filament may exceed the mass of tungsten lost in the same interval, proving that the emitted electrons are not furnished at the expense of the tungsten. They must therefore flow in from outside points of the circuit. Thus these experiments furnish a direct proof that the electric current in metals is carried by moving electrons. The mechanism of metallic conduction becomes more mysterious every day, but this, at any rate, is a fact which has to be reckoned with.

Perhaps I can drive these matters home to you more effectually by means of a simple experiment which shows that these electron currents from tungsten in high vacua are not minute affairs requiring elaborate apparatus for their detection, but, at high temperatures, are of such magnitude as to be worthy of the consideration of the practical electrician. Ì have here a tungsten lamp, containing a filament 14 mm. long and about 3 mils. in diameter, in series with an ammeter, a resistance, a battery, and a second ammeter. They are arranged in the order named, so that there is an ammeter at each end of the lamp. In addition there is a side line from the cylindrical electrode of the lamp which can be switched through either a millammeter or an electric bell to the positive end of the battery. There is no auxiliary voltage in this side line. When I turn the current on you observe that the ammeters read differently, showing that more current is flowing into the filament at one end than out of it at the other. The difference is, in fact, equal to the electron current which flows into the wire sideways, and is registered by the millammeter. Those of you who cannot see the instruments will, at any rate, hear the electric bell when I switch the electron current through it. With a lamp which was somewhat better designed for the purpose than the present one, I have recorded a current of 07 ampere at one end, 0-45 at the other, and 0.25 in the branch circuit. So far as my experience goes, the only limit to the size of these electron currents is that which is set by the magnitude of the current which fuses the filament, provided the requisite driving voltage is available.

UNIVERSITY AND EDUCATIONAL

INTELLIGENCE.

CAMBRIDGE.-Mr. C. T. R. Wilson, F.R.S., University lecturer in experimental physics, has been elected to a fellowship in Sidney Sussex College for a period of five years.

Messrs. C. C. Bissett, of Emmanuel College; H. B. Cronshaw, of Gonville and Caius College; H. Ogden, of Emmanuel College; and E. P. Farrow, of Trinity College, research students of the University, have qualified for the degree by the presentation of theses, which have been approved, in chemistry, mineralogy, physics, and botany respectively.

The Harkness Scholarship in geology and palæontology has been awarded to Mr. W. H. Wilcockson, of Gonville and Caius College, and the Wiltshire prize in geology and mineralogy to Mr. D. B. Briggs, of Jesus College. The Frank Smart prize in botany has been awarded to Mr. E. J. Maskell, Emmanuel College, and that in zoology to Mr. L. T. Hogben, of Trinity College.

The following lecturers have been reappointed for five years from October 1, 1915:-Dr. Searle and Mr. C. T. R. Wilson, in experimental physics; Dr. Marr,

in geology; Dr. Shore, in physiology; and Mr. J. H. Grace, in mathematics. Mr. C. Warburton has been reappointed demonstrator in medical entomology for a period of three years.

GLASGOW.-On June 21 the honorary degree of Doctor of Laws (LL.D.) was conferred upon Prof. G. B. Mathews, F.R.S., formerly fellow of St. John's College, Cambridge, and Dr. G. S. Middleton, president of the Association of Physicians of Great Britain and Ireland. Other doctorates conferred on the same day were:-Doctor of Philosophy (D.Phil.), H. A. Reyburn; and Doctors of Science in Public Health (D.Sc. Pub. Health), A. A. Jubb and P. L. Sutherland.

LONDON. Sir Alfred Pearce Gould has been elected Vice-Chancellor in succession to Sir Wilmot Herringham. For several months past Sir Alfred has been acting Vice-Chancellor in view of Sir Wilmot's absence on active service.

The Senate, at its meeting on June 16, appointed Dr. W. H. Bragg, F.R.S., to the Quain chair of physics, tenable at University College, in succession to Prof. F. T. Trouton. Dr. Bragg is at present Cavendish professor of physics in the University of Leeds.

The D.Sc. degree in chemistry has been granted to Mr. H. V. A. Briscoe, Imperial College (Royal College of Science), and the D.Sc. degree in physics to Mr. Thomas Barratt, Imperial College (Royal College of Science) and East London College, and to Mr. A. E. Oxley, an external student.

OXFORD.-The School of Geography has announced courses of lectures and practical instruction to be given next term on the following subjects :-Central Europe, physical and economic; geographical distribution of man and of rural occupations; form and movements of the earth (Prof. Herbertson); geography of Britain (Mr. Beckit and Miss MacMunn); land forms (Mr. Beckit); meteorology (Mr. Kendrew); surveying (Mr. MacKenzie). Lectures will be given on general geology and the geology of India by Prof. Sollas, and on the historical geography of Great Britain by Mr. C. Grant Robertson.

The committee for anthropology announces lectures and informal instruction on physical anthropology, psychology, geographical distribution, prehistoric archæology and technology, social anthropology and philology. The lecturing staff includes Prof. A. Thomson, Mr. H. W. Blunt, Mr. H. Balfour, the Rector of Exeter College, Prof. J. L. Myres, Prof. Sollas, Mr. E. T. Leeds, Mr. E. F. Carritt, Mr. Griffith, Dr. Marett, Prof. Vinogradoff, Mr. C. Bailey, Prof. Macdonell, Mr. V. A. Smith, Mr. S. Langdon, Mr. P. Manning, Prof. Wright the Principal of Jesus College, Prof. J. A. Smith, and Mr. A. C. Madan. Special lectures for Sudan probationers will be given by Mr. H. Balfour and Dr. R. R. Marett.

MR. S. C. LAWS, principal of the Loughborough Technical Institute, has been appointed principal of the Wigan Mining and Technical College.

IN its issue for June 4 Science announces the following gifts to American universities. Dr. L. D. Waterman, of Indianapolis, professor emeritus in the Indiana University School of Medicine, has made a gift to Indiana University amounting to 20,000l., subject to an annuity during his lifetime, on the condition that the University devotes an amount equal to the income from this gift, the entire proceeds to be used for scientific research. The conditions and gift have been accepted by the University. Mr. A. Bonnheim, of Sacramento, has given to the University of California an endowment of 6000l., with provision for

its subsequent increase to 32,000l., the income to be devoted to the maintenance of scholarships. Another gift of 17,000l. has been made for the erection of dormitories at Cornell University. This gift comes from the same anonymous contributor of 50,000l. some time ago.

In his last report to the Union Government of South Africa, the Secretary for Agriculture points out that the difficulty of procuring good men to fill the scientific and administrative posts in the Department, which has been commented on before, continues. Men of moderate attainments are plentiful and easy to obtain, but good men are more in request than ever. It also appears as if men who are really worth having, and therefore usually in a position to choose, prefer to work in universities and other learned institutions which are independent or semi-independent of Government control, or engage in business on their own account, rather than in Government Departments, as in the former they have more scope and freedom of action and have not to waste time by furnishing multitudes of returns and continually explaining and demonstrating the necessity for their existence. Seeing that the value of the Department to the country depends in the first instance entirely upon the quality of its professional and administrative officers, this is a very serious matter. Efforts are being made to overcome the difficulty of obtaining professional and technical officers by giving scholarships to likely young men to study at institutions abroad, at which they can get the best training obtainable in their particular subjects. The course of study is usually a four years' one, and a number of scholars have already returned and been drafted into the Department. It is considered that this is one of the best methods of obtaining officers for the Department, but it may not entirely suffice, and from time to time officers will have to be appointed from wherever they are obtainable, as at present.

SOCIETIES AND ACADEMIES.

LONDON.

Linnean Society, June 3.-Prof. E. B. Poulton, president, in the chair.-The Misses Katherine Foot and E. C. Strobell: The results of crossing two Hemipterous species, with reference to the inheritance of two exclusively male characters. This may be considered as a continuation of the paper published in the Society's Journal (zoology), xxxii. (1914), pp. 337-373, on crossing Euschistus variolarius with E. servus, and the inheritance of a spot on the genital segment, which was an exclusively male character in the former species. The newly-discovered male character now investigated is the length of the intromittent organ, and is tabulated in the paper. The results of the crossing were not in accordance with Mendelian ratios as regards F, individuals. The authors further show that male characters can be transmitted without the Y chromosome. H. W. Monckton: Note on the plantassociation at the foot of the Boium Glacier, Norway. The Boium is one of the larger glaciers which descends from the great Jostedals snow-field. It flows down into a head-valley of the Fjaerlandsfjord, and the foot of the ice is 492 feet above the sea. latitude is between 61° and 62°, that is a little north of the Shetlands. At the foot of the ice there is the usual desolate space with fresh moraine, and plants are gradually finding their way on to this ground. In places where the ice has advanced a little, plants may be found growing and flowering close to the glacier itself. Among the plants thus creeping on to the moraine were noticed a combination of mountain and

The

valley forms of mountain plants there were :-Salix herbacea, L., Saxifraga stellaris, L., and Phyllodoce caerulea, L.; and of forms of general distribution which one does not usually associate with glaciers there were Alchemilla alpina, L., Trientalis europaea, L., Pirola minor, L., Pinguicula vulgaris, L., Phegopteris Dryopteris L., Lotus corniculatus, L., Sagina procumbens, L., and a species of Epilobium.-Dr. Otto Stapf: The Dragon Tree of Tenerife. The author showed various illustrations of the celebrated tree at Orotava, and especially a drawing by Don Augustin Monteverde, dating from the earlier months of 1819, before the tree was partially destroyed by a gale on July 21, in that year. This drawing is the property of Dr. Perez, of Orotava, who had sent it to Kew for comparison with other illustrations. Dr. Stapf discussed the known history of the dragon tree of the Canaries and notices of it from early writers, referring inter alia to the resinous product known as "Dragon's Blood," formerly used as a pigment and in medicine, but now almost restricted to colouring varnishes.

Zoological Society, June 8.-Dr. S. F. Harmer, vicepresident, in the chair.-G. Jennison: The "nest made by a chimpanzee_in_the Belle Vue Zoological Gardens, Manchester.-R. I. Pocock: The feet, scentglands, and other external characters of the Paradoxurine Viverrids, belonging to the genera Paradoxurus, Arctogalidia, Arctictis, and Nandinia. It is shown

how these may be distinguished collectively from the Viverrine genera (Genetta, Viverra, etc.), and also how they may be differentiated from each other in the characters discussed.-Dr. A. Smith Woodward: The skull of an extinct mammal related to Eluropus, obtained from a cave at the ruby mines, Mogok, Upper Burma. The skull is described as the type of a new genus and species.-Miss K. M. Parker: The early development of the heart and anterior vessels in marsupials, with special reference to Perameles.Lieut. R. Broom: Certain Triassic Stegocephalians. Restorations are given of the skulls of Brachyops laticeps, Owen, and Bothriceps australis. Huxley, which are regarded as forming, with Batrachosuchus browni, Broom, a distinct family, Brachyopidæ. Bothriceps huxleyi, Lydekker, is shown to differ from Bothriceps australis in the structure of the occiput, and in having numerous small teeth on the parasphenoid, pterygoids, and prevomers, and thus to belong to a very distinct new genus.

Geological Society, June 9.-Dr. A. Smith Woodward, president, in the chair.-R. H. Rastall and W. H. Wilcockson: The accessory minerals of the granitic rocks of the English Lake District. The rocks described are the granites of Skiddaw, Shap, and Eskdale, the microgranite of Threlkeld, and the granophyre of Buttermere and Ennerdale. The material was pounded in a mortar, washed and panned, and the concentrate separated in bromoform after the removal of the magnetic portion. The results showed a variation of accessory minerals between the different intrusions, but a similarity between parts of the same intrusion, although the minerals of apophyses are not always the same as those of the main mass. One remarkable result obtained is the rarity of magnetite and the prevalence of pyrrhotite, which was present in every sample examined. Attention was directed to the characteristics of the zircon-crystals, which lent no support to the occurrence of definite types in granite and gneissose rocks respectively. In parts of both the Skiddaw granite and the Threlkeld microgranite, anatase and brookite were found in abundance. Epidote is the characteristic mineral of the Ennerdale granophyre, while garnet is abundant at Threlkeld and Eskdale. The Eskdale granite also contains much tourmaline. The Shap granite is characterised by

A

apatite and sphene. Descriptions of accessory minerals founded only on examination of rock-slices are inadequate and misleading.-F. P. Mennell: The rocks of the Lyd Valley, above Lydford (Dartmoor). small area on the north-east of Dartmoor is chiefly considered, though some of the conclusions are applicable to nearly all that part of the moor which lies north of the portion mapped by the Geological Survey. In the neighbourhood of Lydford the alteration of the Carboniferous rocks within the metamorphic aureole surrounding the granite is described, and it is shown that they are consistently cordierite- and biotite-bearing. North of the altered limestone the type of alteration is different, and leads to the inference that the beds are distinct. The change is of more than local significance, as from this point all round the north of the moor there is no bed of any thickness containing cordierite, while chiastolite, white mica, and andalusite proper, are characteristic. Coarse andalusite-rock and altered shale, with remarkable skeleton-crystals of chiastolite, are described from the Nodden quarries, The together with other types of hornfels. beds occupying the northern part of the contact-zone belong to a definite series. There is evidence that the cover of the granite mass has a dome-like character, and that the same stratigraphical horizon is in contact with the granite all the way from Sourton to Drewsteignton. The granite of Brator is described. It is a biotite-bearing rock containing a little microcline, as well as orthoclase and oligoclase. It is rich in cordierite, recrystallised from sedimentary material absorbed into the magma.

Physical Society, June 11.-Dr. A. Russell, vice-presi dent, in the chair.-E. A. Griffiths and E. Griffiths : The coefficient of expansion of sodium. The thermal expansion and increase in volume on liquefaction of sodium were determined by a method based on the following principle:-The difference in expansion of a volume of sodium and an equal volume of glass (or quartz) was measured by differential weighing under oil at various temperatures. A volume of about 250 c.c. of sodium was suspended from one arm of a short beam balance and a weighed glass bulb of equal displacement from the other arm. Sodium expands uniformly with the temperature up to its melting point. The value 0.000226 was deduced for the coefficient of expansion. In changing from the solid to the liquid state, an increase of 2.57 per cent. occurs in the volume.-T. Smith: Notes on the calculation of thin objectives. Lens systems which are symmetrical about an axis have in general six degrees of freedom for first-order aberrations. Thin systems have only three degrees of freedom, and in consequence of the limited range of glasses only two degrees of freedom are practically available. In achromatic combinations of two lenses these two degrees of freedom are controlled by the general shape as distinct from the total power of each lens. In general when two given conditions are satisfied the curvatures of the inner surfaces are not equal, so that a cemented combination of two lenses is not possible. Owing to the increased light transmitting powers it is often necessary to have only two glass air surfaces, and thus more than two component lenses are necessary. The effect of bending any thin system as a whole by increasing the curvature of each surface by the same amount is investigated, and it is shown that with two given kinds of glass a triple cemented lens can be formed satisfying two arbitrary aberration conditions. Illustrations are given of astronomical objectives of both double uncemented and triple cemented forms, and the glasses are determined for which a doublet can be cemented.-T. Smith: Tracing rays through an optical system. Trigonometrical formulæ have been used for tracing rays not lying entirely in one plane through optical

systems, as these can readily be arranged in a form suitable for logarithmic calculation. When a calculating machine is available such computations can be carried out more expeditiously by using algebraic formulæ; in form these correspond with the expressions for paraxial rays, and a comparison of the numerical result is likely to suggest what alterations should be made when a general ray does not behave as desired. If the two points in which a general ray meets an axial plane are defined as conjugate points, all pairs of conjugate points on a ray are connected by the same relations as hold for object and image points for paraxial rays, and the theory for paraxial rays can be extended to rays in general by placing a suitable interpretation on magnification, etc. The definition of conjugate points can be extended to include rays lying in axial planes, in which case the one point marks the intersection of the ray with the radial focal line formed by rays passing through its conjugate.-H. R. Nettleton: The accuracy of the lens and drop method of measuring refractive index. A simple arrangement for comparing on an optical bench the refractive indices of liquids for monochromatic light by the lens and drop method is described. The accuracy and sensibility of the method are discussed. Attention is directed to the accuracy obtainable in measuring a small radius of curvature of a lens face in terms of the well-known refractive index of water, and in measuring the refractive index of the glass of a lens.

Royal Meteorological Society, June 16.-Prof. H. H. Turner: Discontinuities in meteorological phenomena. Meteorological history is divided into "chapters" averaging 6 years long, with abrupt changes (or "discontinuities," as the author calls them) between. The dates of change are apparently settled by the movement of the earth's axis. They oscillate about mean positions in a cycle of 40-5 years, which appears in Brückner's collected "cold winters

for 800 years; in Nile flood records for 1000 years; and in measures of Californian tree rings for 520 years. The chapters are alternately hot and cold, wet and dry, as shown by rainfall and temperature records at Greenwich, Padua, and Adelaide.-C. Harding: Battle weather in western Europe, nine months, August, 1914, to April, 1915. The author briefly described the weather conditions bordering on the battle area of the western front. At the commencement of the war generally bright and dry weather prevailed, with occasional short spells of rain, but from mid-October to the end of February rainy and rough weather continued with but little cessation. Taking widely distributed stations over the British Isles, it was shown that the rainfall for the nine months in the north and west was below the average, but in the south and south-east it greatly exceeded the normal. With the western Continental stations the rainfall for the same period was everywhere excessive. The author says:-"It is not suggested that in the recent wet weather the rainy conditions have been generated by gun-firing, but it seems quite possible that at times, when the conditions are favourable to rain, the rains have been augmented or accelerated by the concussion initiated over the battle-grounds."

DUBLIN.

Royal Irish Academy, June 14.-Sir John Ross of Bladensburg, vice-president, in the chair.H. Ryan and Miss P. O'Neill: Studies in the diflavone group. II. Derivatives of diflavanone. By the action of benzaldehyde on diacetoresorcinol four isomeric substances were obtained. Three of these were cis-trans stereoisomeric dihydroxydichalkones, and the fourth was a structural isomeride of the others. a-Dihydroxydichalkone in the presence

of alcoholic hydrochloric acid condensed with benzaldehyde, anisaldehyde, and piperonal, to yield dibenzylidene, dianísylidene, and dipiperonylidene derivatives of diflavanone. It was also found that dibenzylidenediflavanone can be obtained directly from diacetoresorcinol by condensation with excess of benzaldehyde in the presence of alcoholic hydrochloric acid, and in the same way the authors obtained dipiperonylidenedimethylenedioxydiflavanone. The latter method

was also found well suited for the preparation of analogous monoflavanone derivatives, and was applied to the preparation of the flavindogenides derived from gallacetophenonedimethylether on the one hand, and benzaldehyde, anisaldehyde and piperonal on the other. PARIS.

Academy of Sciences, June 7.-M. Ed. Perrier in the chair.-A. Lacroix: Some remarkable contact metamorphic phenomena of Madagascar granite. A description of a new type of amphibole, termed imerinite, intermediate between the richterites and glaucophanes; petrographic examination proved the presence of monazite as well as other minerals. As the presence of the monazite appeared singular, several grams were isolated and analysed and proved to contain 1.05 per cent. of thoria, ceria, 39.51 per cent. oxides of lanthanum and didymium, 27.80 per cent. The thorium is unusually low.-G. Bigourdan: Equatorial observations of comets, minor planets, etc., made between 1880 and 1904.-Jules Amar: Functional re-education. A description of a new arthrodynamometer for measuring the values of the angular displacements of the limbs and absolute forces exerted by groups of muscles in the case of invalids recovering from wounds.-M. Agnus: The echo of the ball and shell. An explanation of the double detonation heard on the discharge of a rifle or gun.-Stanislas Meunier: The structure of the Kodai Canal meteorite (India); an example of cataclasis in meteoric irons.-P. Maze: The rôle of chlorophyll. The author regards the pigments in the higher plants as possessing a purely physical function, and considers the direct controlling action of chlorophyll on the assimilation of carbon dioxide as doubtful.Em. Bourquelot and A. Aubry: A comparative study of the influence of acetic acid on the synthetising and hydrolysing properties of a-glucosidase (glucosidase from low yeast, air dried). This ferment is very sensitive to the poisonous action of acids. It is destroyed in liquids containing very small proportions of acetic acid, and the fact that the two properties of synthesis and hydrolysis disappear simultaneously under the influence of these quantities demonstrates that both properties belong to one and the same

enzyme.

June 14.-M. Ed. Perrier in the chair.-J. Boussinesq: The approximate calculation of the effect of climate on the velocity of increase of temperature with depth in the soil.-C. Guichard: The W congruences which belong to a complex of the second order. Case where the equation in S has a triple root.-Pierre Delbet Pyoculture. Pus from a wound is suggested as the culture medium in vitro. It is concluded that if the general and local conditions are such that the patient cannot make headway against the microorganisms, then the latter will multiply rapidly in the pus secreted. If, on the contrary, the conditions are favourable, then the pus will be a less suitable medium of growth than the ordinary media. These hypotheses have been confirmed experimentally, and details of the method of applying them in practice are given.Ernest Lebon: A new table of divisors of numbers.E. Bompiani: The linear element of hyper-surfaces.Arnaud Denjoy: Derived numbers.-Thadée Peczalski: Researches on thermal conductivity. A description of a new arrangement for the determination of the

thermal conductivity of lead.-B. Bogitch: The superficial deformations of steels tempered at moderate temperatures. A study of the corrugations produced on a surface of polished steel on cooling down suddenly from temperatures of 225° to 400° C.-Louis Gentil: The Middle and Upper Cretacian in western Haut Atlas, Morocco.-D. Eginitis: Recent earthquakes at Leucade and Ithaca.-H. Colin: The distribution of invertine in the tissues of the beetroot at different periods in its growth.-F. Bordas: The sanitation of the camps and battlefields. Residual heavy tar oil, freed from napththalene and phenol, mixed with sodium resinate, forms a stable emulsion with water. This mixture is suggested as specially suitable for preventive treatment against flies.-J. Bergonié: The vibrations caused by an electromagnet worked with alternating current in non-magnetic bodies.-Th. Guilloz: The electric needle for the detection of projectiles in the human body.

BOOKS RECEIVED.

First Course in Chemistry. By W. McPherson and W. E. Henderson. Pp. x+416. (Boston and London Ginn and Co.) 5s. 6d. Geographic Influences in Old Testament Masterpieces. By Prof. L. H. Wild. Pp. xiii+182. (Boston and London: Ginn and Co.) 4s. 6d.

Reports from the Laboratory of the Royal College of Physicians, Edinburgh. Vol. xiii. Edited by Dr. J. J. G. Brown and Dr. J. Ritchie. (Edinburgh: Oliver and Boyd.)

Whitby Wild Flowers. By B. Reynolds. Pp. 60. (Whitby Horne and Sons.)

:

IS.

Educative Geography. By J. L. Haddon. Pp. 76. (London: G. W. Bacon and Co., Ltd.) IS. net. Memoirs of the Indian Meteorological Department. Vol. xxi. Part x. Correlation in Seasonal Variations of Weather. iv., Sunspots and Rainfall. By Dr. G. T. Walker. Pp. 17-59. (Simla: Government Central Branch Press.) 1.8 rupees.

A Critical Revision of the Genus Eucalyptus. By J. H. Maiden. Vol. iii. Part 2. Pp. 23-44+4 plates. (Sydney: W. A. Gullick.) 2s. 6d. Field Book of American Trees and Shrubs. By F. S. Mathews. Pp. xvii +465. (New York and London: G. P. Putnam's Sons.) 7s. 6d. net. Genetic Theory of Reality. By Dr. J. M. Baldwin. Pp. xvii +335. (New York and London: G. P. Putnam's sons.) 7s. 6d. net.

The Chemist's Year Book.

Edited by F. W. Atack. 2 vols. Pp. 914. (London and Manchester: Sherratt and Hughes.) 10s. 6d. net.

The Investigation of Mind in Animals. By E. M. Smith. Pp. xi + 194. (Cambridge: At the University Press.) 3s. net.

St. Bartholomew's Hospital in Peace and War. By Dr. N. Moore. Pp. iv + 56. (Cambridge: At the University Press.) 25. net.

A Report on Researches on Sprue in Ceylon, 1912–14. Pp. x+155. (Cambridge: At the University Press.) 7s. 6d. net.

A Map of the Western War Area. From the Seine to the Rhine, and from the Swiss Frontier to the Rhine Delta. With Contour Lines and Layered Colouring. Style B. Mounted in Sections, without Names. (Oxford: University Press.) 12s. 6d. net. Our British Snails. By Rev. Canon J. W. Horsley. Pp. 69. (London: S.P.C.K.) IS. net.

The Beothucks or Red Indians: the Aboriginal Inhabitants of Newfoundland. By J. P. Howley. Pp. xx+348+ plates xxxvii. (Cambridge: At the University Press.) 21S. net.

The Evolution of the Potter's Art. By T. Sheppard. Pp. xx. (London: A. Brown and Sons, Ltd.)

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