two to sight weeks after the paraplegia was complete, living altogether up to eleven or twelve months. At no time were any Trypanosomata found in the blood, nor post mortem in the viscera or glands. But in the spinal cord they were present in smail numbers, and inoculation of the cord into other rats has produced similar symptoms, whilst inoculation of the organs has been negative. In sections of the spinal cord amoeboid and adult forms of the Trypanosoma have been found, and also those lesions which Dr. Mort found in the nervous system of man in cases of sleeping sickness, viz., a considerable cellular exudation around the vessels. This is not found in monkeys, in which the organisms become generalised, and do not get localised in the nervous system as is the case in rats.

These experiments go to show that the organisms associated with the diseases of Gambia fever and sleeping sickness, which are thought by some to be the same disease in different stages, are quite distinct in their effects, and they are also distinct morphologically; that the Trypanosoma of sleeping sickness can be inoculated into rats, which has been denied; and that there is a great similarity in the lesions produced in the nervous systems of man and of rats, and in the localisation of the disease to the nervous system.

From experiments made, a double infection would seem to be quite possible, and to be a likely event in these diseases.

January 26.- On the Modulus of Torsional Rigidity of Quartz Fibres and its Temperature Coefficient. By Dr. Frank Morton, St. John's College, Cambridge, late Mackinnon Student. Communicated by Prof. J. J. Thomson, F.R.S.

In this research the dynamical method of experimenting was employed, and the investigaton was divided into three parts:

(1) The determination of the absolute value of the torsion modulus.

(2) The variation of the modulus between 15° C. and 100 C.

(3) The variation of the modulus between 20° C. and 1000° C.

The radii of the fibres used were determined by measuring their circumferences, the fibres being rolled between two fine glass capillary tubes and the number of revolutions made in travelling a distance of 5 mm. counted. By this method fibres of diameter 0.001 cm. were measured to 0.01 per cent.

In the second part of the research the jacket enclosing the fibre was heated by using the vapours of various liquids boiling under atmospheric pressure. The modulus of rigidity was found to increase as a linear function of the temperature, but the values of the temperature coefficient of the modulus obtained from different fibres were considerably different. In the experiments between 20° C. and 1000° C. the fibres were suspended inside a platinum tube, which was heated electrically. It was found that the modulus of rigidity increased with the temperature, at first as a linear function of it, but as the temperature rose the rate of increase gradually diminished and a maximum rigidity was attained at about 880° C. After passing this point the rigidity decreased very rapidly with increase of temperature.

Note on the Cause of the Period of Chemical Induction

in the Union of Hydrogen and Chlorine." By D. L. Chapman and C. H. Burgess. Communicated by Prof. H. B. Dixon.

The induction period in the union of hydrogen and chlorine exposed to light, which has been ascribed by various authors either to a change in the physical condition of the chlorine or of the mixture of hydrogen and chlorine, or to the primary formation of an unstable intermediate compound, has been shown by the authors to be due to impurities. The impurities are those which react with chlorine, such as ammonia and sulphur dioxide. At the ordinary temperature in the dark the reaction between these substances and chlorine is not completed. In the light or by raising the temperature these impurities can be entirely removed by the chlorine. The time required for their removal is the induction period during which

the chlorine is rendered incapable of combining with the hydrogen.

It has been hitherto supposed that an induced mixture of hydrogen and chlorine if left to stand for some time in the dark must be again induced before combination will proceed at its normal rate. This is not the case if a quartz actinometer is substituted for a glass one.

"The Theory of Symmetrical Optical Objectives.-Part II." By S. D. Chalmers. Communicated by Prof. Larmor, Sec.R.S.

In photographic objectives, consisting of two similar lenses symmetrical to a central stop, the back member is generally corrected for spherical and chromatic aberrations, astigmatism, and curvature of field for distant objects, and thus the whole system is perfectly corrected for unit magnification. The present paper discusses the aberrations for distant objects. In part i. it was proved that, to the first approximation, the above defects are corrected in the whole system when they are corrected in the single member. By geometrical constructions, using the symmetry with respect to the axis and to the stop, these results are extended to practical systems. The paths of parallel rays, incident on the combined system, are obtained from those of two sets of parallel rays incident on the single system; the aberrations of the combined system are expressed in terms of the single system with small errors negligible in practical systems-due to the image of the stop being imperfect.

"Exterior Ballistics. Error of the Day and other Corrections to Naval Range Tables." By Prof. Geo. Forbes, F.R.S.

Gun-sights are always marked for standard conditions of muzzle velocity (m.v.) and air density (a.d.). When either of these change the sights must be corrected. The author finds from theory that if a.d. is increased m fold, and the range is diminished m fold, then the elevation and time-of-flight must be diminished m fold; and, empirically, that up to 10° of elevation (10,000 yards for a 12" gun) elevation varies very closely as 1 [m.v.], as in vacuo. On these laws he calculated from the naval range table of a 12" gun, 850lbs. shot, 2463 m.v., at 2, 4, 6, 8, and 10 thousand yards, the table for a 6′′ gun, 100lb. shot, 1960ft. secs. The elevations only differed from the Naval 6" table by -I, -4, -2, +2, and +4 min. of arc.

The laws, therefore, may be applied with perfect confidence for the comparatively small variations that occur in any one gun.

Linnean Society, January 19.—Prof. W. A. Herdman, F.R.S., president, in the chair.-The Rev T. R. R. Stebbing exhibited and explained specimens of Crustacea, in various ways remarkable for structure, habits, habitat, or colouring.-Botanical collecting: Dr. A. Henry. The actual methods were briefly alluded to, stress being laid on truthful labelling of the specimens at the moment of collection, instead of months afterwards, when identical numbers were often given to plants of different provenance. Dr. Henry described observations made by him in China. He alluded to mimicry in plants, in the case of two species of Lysimachia (a protomorphic genus in China), one of which mimicked Paris quadrifolia, with 4 leaves, while the other recalled another species of Paris with 10-12 leaves. He referred also to the extraordinary richness of species on calcareous soils as compared with other soils, a fact constantly seen in China, and well marked also in France, and asked for some explanation. In China, as elsewhere, pure woods were rare, being only formed by a few conifers, like Abies Fargesii at high altitudes in Hupeh, Cupressus funebris in the same province at lower levels (the home of the Reeves's pheasant), Pinus Massoniana (almost everywhere in the central and southern provinces), other species of Pinus more local; also certain species of oak widely distributed; and Alnus nepalensis in Yunnan. The explanation of the occurrence of pure forests was also a subject not completely understood: e.g. in this country ash seeded freely, and in some places for a time looked as if it would grow into a pure wood; but apparently pure

forests of ash only occurred on extremely rich soil in some districts in Russia. With regard to botanical collecting, three stages had occurred. At an early period plants were collected to be merely named and classified; in fact, they were treated like postage stamps. The second period began with Sir Joseph Hooker, who inaugurated the study of the geographical distribution of plants. The third period, that of the present day, was a step forward, in that attention should be paid to the plants themselves as social organisms, living in harmony and yet in competition together; and Dr. Henry urged that the time had come when the hunt for new species should cease to be the sole aim of the collector, and the study of the known species be taken in hand in their living conditions. He advocated map-making of small areas, census-taking, measurements, records of natural seedlings, soil, shade, &c., and to illustrate this plan showed a series of slides taken in France, the idea of which was to explain how the commoner species of trees behaved at different altitudes and on different soils.-Cranial osteology of the fishes of the families Osteoglossidæ, Pantodontidæ, and Phractolæmidæ : Dr. W. G. Ridewood. This paper is a fourth instalment of the results of an extensive investigation upon the skull of the lower teleostean fishes begun in 1896. Descriptions are given of the skulls of Osteoglossum, Heterotis, Arapaima, Pantodon, and Phractolamus; and in a summary Dr. Ridewood points out that the evidence of the skull goes to show that the three genera Osteoglossum, Heterotis, and Arapaima, first brought together into the family Osteoglossidæ by Dr. Günther, constitute a perfectly natural group; that the Pantodontidæ are more closely related to the Osteoglossidæ than to any other family of fishes, as has been suspected since the first discovery of the genus Pantodon in 1876; and that the Phractolæmidæ do not in their cranial osteology offer any evidence of close alliance with either of these families.

February 2.-Prof. W. A. Herdman, F.R.S., president, in the chair.-Descriptions of some new species and notes on other Chinese plants: W. J. Tutcher. The species in question had been found on the island of Hong Kong, with one from Kowloon and one from Wei-hai-wei. Bentham's "Flora Hongkongensis " in 1861 enumerated 1053 species from the island, 159 of which had not at that time been found elsewhere, but at the present time only about 50 of these remain peculiar to the island. The flora as now known amounts to about 1400 species, of which 100 are regarded as endemic, though probably many will be found natives of the mainland Ferns amount to 100; grasses about as many; Leguminosæ nearly as many; between 70 and 80 Cyperaceæ; Compositæ more than 60, and orchids 60. Quercus Eyrei, first found by Capt. Champion, was not collected by any recent collector until the author re-found it in quantity; even Hance had declared that Champion must have been mistaken in his locality. The luxuriance usually associated with tropical vegetation is here wanting, due to the poverty of the soil, which is almost exclusively disintegrated granite. The new territory leased to Great Britain in 1898 has an area of about 300 square miles, that is, ten times the area of Hong Kong. Lantao is an island resembling Hong Kong, but its highest peak is 3050 feet, with many well-wooded ravines, and when explored will doubtless prove rich in plants.-Revision of the European marine forms of the Cirolaninæ, a subfamily of Crustacea Isopoda: Dr. H. J. Hansen. Three new species are described-Cirolana gallica, C. Schmidtii, and Eurydice affinis. Comparative tables of the genera and species are supplied, distinguishing eight European species of Cirolana, one of Conilera, and six of Eurydice.

Challenger Society. January 25.-Sir John Murray in the chair.--Mr. E. W. L. Holt exhibited and made remarks on some rare and interesting deep-water fish and Crustacea from West Ireland.-Dr. R. N. Wolfenden exhibited and made remarks upon some Copepoda from the Gauss (German Antarctic) expedition; their large size, up to 10mm., was remarkable, as also the fact that, of the 42 species from the Gauss and Belgica, five were common to the subpolar seas and continuous by way of the mesoplankton.

Sir John Murray spoke on the relation of oceanography to other sciences. He pointed out that recent expeditions had made only inconsiderable alterations in the contour lines of the sea-bottom published in the Challenger reports, and was of the opinion that no great changes were likely to be made by the soundings of future expeditions. He expressed his belief that the great ocean basins had been practically unaltered through geological time, but that the continents, including a zone of not more than 200 miles seaward of their present outline, had frequently altered their levels, supporting this belief by the fact that all known sedimentary rocks are of "terrigenous "character, to the exclusion of deep-sea materials. The meteorology of midocean, where the diurnal temperature range of the water is about 2° F., was contrasted with the meteorology over land-masses, where absorption and radiation are high, and the diurnal atmospheric range may amount to 80° F. As an example of the far-reaching effects of temperature, Sir John Murray cited the range of annual variation where hot and cold currents are at war, amounting in some cases to 40° F.; in such regions the animal death-rate is very high, and the dead organisms decomposing on the bottom start the formation of glauconite, a well-known constituent of sedimentary rocks. As another result of temperature, it has been estimated that a tropical Copepod lives twentyfour times as fast as an Arctic Copepod in the same period of time; this may explain the predominance of specimens and paucity of species in the Arctic as compared with the Tropical fauna. In connection with chemistry, he pointed out the gradual transference of lime from the poles to the tropics by organic agency; and, in connection with physiology, the possible relation between the serous and similar fluids of existing organisms, and the constitution of the primæval sea in which life first began on our earth.

The

Faraday Society, January 30.-Prof. A. K. Huntington in the chair.-Mass analysis of Muntz's metal by elec trolysis, and some notes on the electrolytic properties of this alloy J. G. A. Rhodin. The first portion of the paper describes an apparatus which was specially designed by the author for the purpose of the accurate and rapid determination of the copper content (which should lie between 60.5 and 61.5 per cent.) of Muntz's metal. author also discusses the electrochemical properties of Muntz's metal. The metal is largely used as a sheathing to protect ships' bottoms from certain mollusca and algæ, and to be successful it should dissolve in sea-water just to a sufficient extent as to render the surface poisonous, the best conditions being .the equal dissolution of the copper and zinc. The author shows how these may be calculated approximately by supposing that the electrolytic dissolution rate is proportional to the heat of formation of the ultimate compounds (zinc and cuprous chlorides), and to the conductivities of the metals which dissolve.-The equilibrium between sodium sulphate and magnesium sulphate R. B. Denison. Experiments conducted from the standpoint of the phase rule are described, the object of which was to determine whether the double salt of sodium and magnesium sulphates, 2MgSO,.Na,SO,, which has been described as a naturally occurring mineral, is capable of existence in contact with solution, that is, whether it has been formed in nature by the evaporation of saline waters. The corresponding potassium compound is known to occur in Stassfurt as langbeinit, and it was thought that a detailed investigation might result in the isolation of the sodium langbeinit from solution. Dilatometer and tensimeter experiments pointed fairly conclusively to the assumption that the compound sodium-langbeinit cannot exist in contact with solution, at least below 100° C., and hence this substance, if found as a mineral, must be a product of a higher temperature.-Refractory materials for furnace linings: E. K. Scott.

Mineralogical Society, January 31.-Prof. II. A. Miers, F.R.S., president, in the chair.-Danalite from Wheal Maudlin, Cornwall; crystallographic characters of bariumradium bromide: Prof. H. A. Miers.-Epidote from Inverness-shire: H. H. Thomas. The crystallographic and optical characters were described. A chemical analysis made by Dr. Pollard showed that the mineral contained a very low

of finding the form of pontoon which, advancing through the fluid at a given speed, would be unaccompanied by any displacement of fluid surface either before or behind.-A comparison of the lakes of Denmark and Scotland: Dr. Wesenberg-Lund. Dr. Lund had visited Scotland on the invitation of Sir John Murray with the view of making this comparative study. The greatest possible contrasts existed between the lakes of Denmark and the typical Highland lakes of Scotland, the Danish lakes being, for example, comparatively small and shallow, with great variations of temperature from season to season, the water being rich in lime, and the littoral region being characterised in most cases by luxurious vegetation forming the home of numerous animals. Scottish lakes like Loch Leven, however, approximated more closely in character to the lakes of Denmark. The paper contained an important discussion of the fauna of the two types of lakes, and of its influence on the lakes themselves and their surroundings. Danish lakes are gradually being silted up, and will before long disappear, while the lochs of Highland Scotland will remain practically unaltered through long ages.—On a new family and twelve new species of Rotifera of the order Bdelloida J. Murray. The great uniformity of structure hitherto observed throughout the order Bdelloida gives much interest to the discovery in the Scottish lochs of an animal showing great divergence from the general type. The new family, which is called Microdinadæ, is peculiar in the structure of head and jaws. The discs and wreaths are quite absent, so that there is no corona, unless the terminal cilia of the throat are regarded as such. The rostrum and toes are as in the genus Philodina. The jaws

The

of all other Bdelloida are ramate; those of Microdina are between ramate and malleo-ramate or malleate. The large teeth are all towards the anterior end of the jaws, and there are usually from one to two loops on the manubrium. A remarkable feature of the animal by which alone it could be distinguished from all other Bdelloida is a large crimson gland attached to the oesophagus.-Variations in the crystallisation of potassium hydrogen succinate due to the presence of other metallic compounds in the solution: A. T. Cameron. The crystals were obtained from solutions containing small quantities of ferric and chromic compounds, and may be described as oblique elliptic double cones showing curved surfaces only. The crystals belong to the same system as those of the acid succinate, and are evidently modifications due to the presence in small variable quantities of the other metallic compounds possibly in a state of solid solution.-(1) Continuants whose main diagonal is univarial; (2) the eliminant of a set of general ternary quadrics: Dr. Thomas Muir.

MANCHESTER.

Literary and Philosophical Society, January 24.Rigidity of gelatin H. Morris-Airey. After describing some of the properties of aqueous solutions of gelatin, the results of a series of measurements of the rigidity of these media were given. The cause of the period of chemical induction: C. H. Burgess and D. L. Chapman (see p. 380).

PARIS.

Academy of Sciences, February 6.-M. H. Poincaré in the chair. On the stability of ships: E. Bertin.—On the action of hail cannons: J. Violle. There are in the Beaujolais twenty-eight societies for breaking up the hail-storms common in that region by means of the hail cannon. A comparison of the damage done during the period 1891-1900 with the losses through hail subsequent to the introduction of the cannon (1900-1904) shows marked evidence in favour of the use of this means of dispersing the hail clouds. It has been frequently noticed that both lightning and thunder are suppressed within the protected zone, although they may be raging just outside this area.-Syntheses in the anthracene series. Symmetrical diamido-tetra-alkyl derivatives of the dihydride of y-tetraphenyl-anthracene: A. Haller and A. Guyot. As a result of the condensation of y-diphenyl-y-di- | hydroxy-anthracene dihydride with dimethylaniline two stereoisomeric compounds are produced, which, on account of the wide differences in their properties, are very readily separated. A similar reaction takes place with diethylaniline, but the stereoisomers are more difficult to separate.-The sub

stances producing softness in wine: A. Muntz. A discussion of the effect of the gummy matters present in wine on its taste. On the extension of the Cretaceous seas in Africa: A. de Lapparent. Traces left by the seas of the Upper Cretaceous have been recognised for some time in the Sahara and the Soudan, but up to the present there has been no direct proof of a communication between this and the Atlantic. Fossils recently collected by Lieut. Desplagnes and Capt. Théveniaud make the existence of this communication highly probable.-On the three methylcyclohexanones and the corresponding methyl-cyclohexanols: Paul Sabatier and A. Mailhe. The three cresols are readily reduced to the corresponding cyclohexanols by hydrogen in presence of reduced nickel at 200°-220° C. These were converted by heating with zinc chloride into methylcyclohexenes, and by oxidation into methylcyclohexanones. The latter substances are more conveniently obtained from the alcohol by the reaction discovered by Sabatier and Senderens, passing the vapours of the alcohol over copper heated to 300° C., the yield by this method being nearly theoretical.-On a measurement of the height of the reversing layer obtained with the aid of the large telescope of the Observatory of Mont Blanc : M. Millochau. Measurements of two calcium lines under good conditions gave a thickness of o".15.-Observations of the zodiacal light made at the summit of Mont Blanc: A. Hansky. A detailed account of observations taken under very favourable conditions on September 21-22.-On solutions of systems of linear differential equations with monodrome coefficients: Ed. Maillet.-On Poisson's integral and singular lines of analytical functions: P. Fatou.-On the whole of the curves traced on an algebraic surface, and on the Picard integrals of this surface: Francesco Severi.— On the deviation of freely falling bodies: M. de Sparre. Reply to a paper of M. Maurice Fouché on the same subject. On a new mechanical clutch: M. Hérisson.-An integrating thermometer: Ch. Féry. A synchronising electromagnetic brake: Henri Abraham. The axis of the motor carries a toothed wheel of copper, the teeth of which pass between the poles of an electromagnet, actuated by the same current as the motor. If synchronism is established, each tooth passes this space at the instant when the electromagnetic field is nil, and there is no braking action. If the synchronism is imperfect, the brake absorbs the whole of the extra energy of the motor.-Magnetic hysteresis at high frequencies in nickel and nickel steels: Ch. Eug. Guye and A. Schidlof.-On the direct fixation of ethero-organomagnesium derivatives on the ethylene linkage of unsaturated esters: E. E. Blaise and A. Courtot. Ethyl methacrylate reacts with magnesium-methyl-iodide giving the tertiary alcohol dimethylpropenylcarbinol, the ketone methyl-ethylacetone, and diisopropenyl. The conditions giving a maximum yield of either of these have been worked out.-On the cryoscopy of the sulphates: Albert Colson.-A new method of testing for ammonia: application to the examination of water for sanitary purposes: MM. Trillat and Turchet. In presence of potassium iodide and sodium hypochlorite, ammonium salts develop a black coloration, due to iodide of nitrogen, which can be estimated colorimetrically. The coloration appears to be less liable to be interfered with by certain substances commonly present in natural waters than is the case with Nessler's reagent.-On the evolution of carbon in combustibles: Isidore Bay and Just Alix. Some hereditary anomalies provoked by traumatisms: M. Blaringhem.-On the use of leucine and tyrosine as sources of nitrogen for plants: L. Lutz. These two nitrogenous substances can be assimilated both by phanerogams and fungi. The difference noted in a previous paper between these two classes of plants was due to the use of sand as a medium for the growth of the former.-On the cause of the impoverishment of springs in plains: M. Houllier. The author draws the conclusion that the progressive impoverishment of the springs in the basin of the Somme during recent years is the result of the increased use of the land for agricultural purposes, leading to a very considerable increase in the amount of water evaporated by plant transpiration.-The proportions of the gases in arterial blood during the course of anesthesia due to chloroform, remaining invariable so long as the pulmonary respiration remains very nearly normal: J. Tissot.-The mechanism of accommodation: H. Bertin-Sans and J. Gagnière. The experiments described, which were carried out with rabbits' eyes, support

Tscherning's theory, as opposed to that of Helmholtz.Observations on the absorption bands of blood and oxyhæmoglobin: MM. Piettre and Vila.-Myelitis produced by tuberculous toxins: E. Clément.--On the constitution of Djebel Hadid: Paul Lemoine.-On the Eocene strata in Western Morocco: A. Brives. On the mode of formation of high glacial valleys: Paul Girardin.

NEW SOUTH WALES.

Royal Society, November, 16, 1904.-Mr. C. O. Burge, president, in the chair.-On the occurrence of isolated crystals i of augite in the tufaceous mudstones near the top of the upper marine series at Gerringong: H. G. Foxall. The author gives the results of crystallographical and chemical examinations of isolated crystals of augite, together with a note on their occurrence.

December 7, 1904.-Mr. C. O. Burge, president, in the chair.-Mr. C. O. Burge delivered his presidential address on the connection between engineering and science. Among the future triumphs of engineering helped by science were mentioned the application of electricity to main line railways. Then there are promises as regards conveyance of power by electricity without wires. Increased economy in the utilisation of heat units in the ordinary steam engine will be a work of the future, thus saving our rapidly diminishing fuel supply. Other subjects mentioned as fit ones for the future were the i direct utilisation of the sun's rays for power, and of the rise and fall of the tide for the same purpose; the diminution of skin friction in ships; and of the resistance to air in ships and trains; the dispersion of fog by electricity; the further investigation of fatigue in metals used for construction; and the application of single phase electricity to traction.-The approximate colorimetric estimation of nickel and cobalt in presence of one another: R. W. Challinor. Use is made of the complementary colours of Ni and Co solutions. The method is to be applied to the solution of the weighed Ni and Co deposited by electrolysis. The mixed metals are dissolved in HNÓ,, the solution evaporated and diluted to a definite volume and a fraction taken. Standard Ni (NO3)2 or Co (NO,), solution is added until the colour matches a neutral tinted solution of known strength; both solutions are brought finally to the same dilution, the colours being compared by looking vertically down the tubes.-Note on a combined wash-bottle and pipette: J. W. Hogarth.

DIARY OF SOCIETIES.

THURSDAY, FEBRUARY 16.

ROVAL SOCIETY, at 4.30.- Polarised Röntgen Radiation: Dr. C. G. Barkla. The Effects of Momentary Stresses in Metals: Prof. B. Hop. kinson. The Halogen Hydrides as Conducting Solvents. Parts I.--IV. : B. D. Steele, D. McIntosh, and E. H. Archibald.-Further Observations on Slip-bands. Preliminary Note: W Rosenhain.

ROYAL INSTITUTION, at 5. Recent Work of the Geological Survey: Prof. J. J. H. Teall, F.RS.

SOCIETY OF ARTS, at 4.30 -The Indian Census of 1901: Sir Charles A. Elliott, K.C.S.I.

LINNEAN SOCIETY, at 8.-A Revised Classification of Roses: J. G. Baker, F.R.S.-The Botany of the Anglo-German Uganda Boundary Commission: E. G. Baker, Spencer Moore, and Dr. A. B. Rendle.

Schistose Breccia: Rev. J. F. Blake.-On the Wash-outs in the Middle Coal measures of South Yorkshire: F. F. Middleton. SOCIETY OF ARTS, at 8.-Some Miscorceptions of Musical Pitch: John E. Borland.

THURSDAY, FEBRUARY 23.

ROYAL SOCIETY, at 4.30 -Probable Papers: On some New Species of Lagenostoma: a Type of Pteridospermous Seed from the Coal-.measures: E. A. Newell Arber.-On a New Rhabdosphere: G. Murray, F.R.S.On Changes observable in the Liver Cells during Digestion, and their Relation to Hepatic Secretion: Prof. E. Wace Carlier. -The ColourPhysiology of the Higher Crustacea. Part III: F. Keeble and Dr. F. W. Gamble.-Phosphorescence caused by the Beta and Gamma Rays of Radium. Part II.-G. T. Beilby.

ROYAL INSTITUTION, at 5.-Recent Work of the Geological Survey: Prof. J. J. H. Teall, F.R.S.

INSTITUTION OF ELECTRICAL ENGINEERS, at 8.-Continuation of Dis cussion:-The Value of Overhead Mains for Electric Distribution in the United Kingdom: G. L. Addenbrooke.

FRIDAY, FEBRUARY 24.

ROYAL INSTITUTION, at 9.-Fungi: Prof. H. Marshall Ward, F.R.S. PHYSICAL SOCIETY, at 5.-On the Curvature Method of teaching Germetrical Optics: Dr. C. V. Drysdale. - Exhibition of Dr. Meisling's Colour Patch Apparatus: R. J. Sowter -A Method of illustrating the Laws of the Simple Pendulum, and an Exhibition of String Models of Optical Systems: J. Schofield.

INSTITUTION OF CIVIL ENGINEERS, at 8.-Morecambe Sewerage: Method of Laying a 15-inch Cast-iron Sewer under the London and NorthWestern Railway: F. D. Flint.-The Reconstruction of Bow Bridge over the River Lea: H. M. Rootham.

The Melting of Floating Ice.-Heat A Lunar Rainbow.-J. McCrae

366

366

F.R.S.

Notes on Stonehenge. III. The Earliest Circles. (Illustrated.) By Sir Norman Lockyer, K. C.B.,

366

Animal Life. (Illustrated.) By R. L.

367

Notes

The Condition of Chemical Industries in France. By W. R.

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Our Astronomical Column::-

371

Blood Pressures in Man. By Prof. T. Clifford Allbutt, F.R.S.

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Radiation Pressure. By Prof. J. H. Poynting,
F.R.S.

Geographical Results of the Tibet Mission
The London Conference on School Hygiene
University and Educational Intelligence
Societies and Academies

Diary of Societies