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during a month or two of rainy season, and how many weeks or months must pass before it gets to the sea, and where it has been in the interval, and what has become of the air from which it fell, we need not wonder that the distance of the earth's axis of equilibrium of centrifugal force from the instantaneous axis of rotation should often vary1 by five or ten metres in the course of a few weeks or months. We can scarcely expect, indeed, that the variation found by the International Geodetic Union during the year beginning June, 1891, should recur periodically for even as much as one or two or three times of the seeming period of 385 days.

Mr.

One of the most important scientific events of the past year has been Barnard's discovery, on September 9, of a new satellite to Jupiter. On account of the extreme faintness of the object, it has not been observed anywhere except at the Lick Observatory in California. There, at an elevation of 4500 ft., with an atmosphere of great purity, and with a superb refractor of 36" aperature, they have advantages not obtainable elsewhere. The new satellite is about 112,000 miles distant from Jupiter, and its periodic time is about 11h. 50m. Barnard concludes a short statement of his discovery with the following sentences :-"It will thus be seen that this new satel lite makes two revolutions in one day, and that its periodic time about the planet is less than two hours longer than the axial rotation of Jupiter. Excepting the inner satellite of Mars, it is the most rapidly revolving satellite known. When sufficient observations have been obtained, it will afford a new and independent determination of the mass of Jupiter. Of course, from what I have said in reference to the difficulty of seeing the new satellite, it will be apparent that the most powerful telescopes of the world only will show it" (dated Mount Hamilton, September 21, 1892).

Sir Robert Ball, in calling my attention to it, remarks that "it is by far the most striking addition to the solar system since the discovery of the satellites to Mars in 1877." To all of us it is most interesting that during this year, when we are all sympathizing with the University of Padua in its celebration of the third centenary of its acquisition of Galileo as a professor, we have first gained the knowledge of a fifth satellite in addition to the four discovered by Galileo.

Rudolph Virchow (COPLEY MEDAL).

Professor Virchow's eminent services to science are known throughout the world, and they are far too varied and numerous for enumeration.

He survives Schwann, Henle, and the other pioneers in several branches of natural history who came from the school of Johannes Müller, and at the present time occupies a position of influence and honour equal to that of his great contemporaries Helmholtz, Ludwig, and Du Bois-Reymond.

His contributions to the study of morbid anatomy have thrown light upon the diseases of every part of the body, but the broad and philosophical view he has taken of the processes of pathology has done more than his most brilliant observations to make

the science of disease.

In histology he has the chief merit of the classification into epithelial organs, connective tissues, and the higher and more specialized muscle and nerve. He also demonstrated the presence of neuroglia in the brain and spinal cord, and discovered crystalline hæmatoidine, and the true structure of the umbilical cord.

In pathology, strictly so called, his two great achievements-the detection of the cellular activity which lies at the bottom of all morbid as well as normal physiological processes, and the classification of the important group of new growths on a natural histological basis—have each of them not only made an epoch in medicine, but have been the occasion of fresh extension of science by other labourers.

In ethnological and archæological science Professor Virchow has made observations which only the greatness of his other work has thrown into the shade; and, so far from confining himself to technical labours, he has been known since he migrated to Würzburg and returned to Berlin as a publicspirited, far-seeing, and enlightened politician."

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Universally honoured and personally esteemed by most of the leading pathologists in this country, as well as on the Contine and in America, who had the good fortune to be his pur Prof. Virchow is a worthy successor of the many illest. men of science to whom the Copley medal has been awardel

Nils C. Dunér, Director of the Observatory of Lund (RUM10, MEDAL).

Dr. Dunér has been continuously at work, since 1871, astronomical observations (see "R. S. Catalogue ").

He began to turn his attention to spectroscopic subjects : 1878, and commenced the publication of his systematic work: Stellar Spectra in 1882.

In 1884 he brought to a conciusion his wonderful observat vn of stars of Vogel's III Class. His memoir contains a deat study of the spectra of nearly 400 stars, all which are most difficult objects to observe. This volume is one of foundations on which any future work in this direction muste based.

In 1891 he published another series of researches on the r tion of the sun, comparing true solar with telluric lines regions up to 75° of solar latitude. The result showed a ciz nution of angular velocity with increasing latitude, thus spect scopically confirming Carrington's results.

Professor Charles Pritchard, D.D., F.R.S., Director of the Oxford University Observatory (ROYAL MEDAL). Professor Pritchard began his publications on astronom♪. subjects in 1852. His first paper and several others which bot followed, have dwelt with the construction of object glasses ar telescope adjustments.

He was president of the Royal Astronomical Society in t years 1867 and 1868.

The ser

He was appointed first Director of the newly-founded obser vatory at Oxford in 1874. It is now the most active Univers observatory in the kingdom, as many as fifteen stude receiving instruction in observatory work at times. vices he has rendered to astronomy in devising, and keeping a high standard, the work of the observatory in many directives including its use as a school, are very noteworthy.

Immediately on the establishment of the observatory he sa the beneficial effects of photographic investigation, and fr applied the method, with the old wet-plate photography, to th problem of the physical libration of the moon. He saw tha this problem was encumbered in heliometric work by the fat that a set of the observations must take a considerable ti and therefore they were made on a constantly changing dr. necessitating great labour in reduction. By the observara being made in two or three seconds, the picture of the moon di not alter in the time. The result was to show import variations from Bouvard's work, which variations in the important particulars were confirmed by Dr. Hartwig.

Next (1885) the relative motions of the Pleiades were take up with a view of tracing gravitational effects in the varic members of the group. This question is not ripe for solving but it induced heliometer observers to take up the question, important progress is now being made.

The photometric work detailed in the "Uranometria Non Oxoniensis," also published in 1885, consisted in measuring the light received from all stars visible to the naked eye, to 10 ̊so1D declination, by means of a wedge photometer devised by Pro Pritchard-a form of photometer now in the hands of mat astronomers. In the course of this work Prof. Pritchard, at bown expense, took an assistant to Egypt to determine the effec of atmospheric absorption in a more constant climate than of Oxford. This photometric work has been recognized by award of the gold medal of the Royal Astronomical Society.

Having fully determined the capacity of photography fr accurate measurement, Prof. Pritchard next applied it to paral determinations of stars of the second magnitude. Some th stars altogether have been investigated, and this work has been published. Thirty is a greater number than any othe astronomer has attempted.

Prof. Pritchard is now working on the International Char the Heavens, and taking part in researches to ensure an accura photometric scale.

John Newport Langley, F.R.S. (ROYAL MEDAL). Some of the most important of Mr. Langley's researches her been upon the Physiology and Histology of Secreting Glands

Extending the observations of Kühne and Lea on the pancreas, Ir. Langley showed in an elaborate series of researches, exending over the salivary and most of the important secreting lands of the body, that the formation, as a morphological lement within the secreting cell, at the expense of its prooplasm, of the material to be used in the secretion is a general inction of secreting cells. The dependence of this function pon the activity of nerves, and upon other forms of excitation, ach as the action of drugs, has been greatly elucidated in he course of these researches. Concurrently with the morphoogical changes within the cells, the chemical changes which ccur within the secretion as the result of nerve activity or inctivity have been investigated, and many important facts rought to light regarding the nature of the action or modifiations of the action which may be brought to bear upon the ecreting cell through the nervous system. These researches re published partly in the Philosophical Transactions, and artly in a long series of articles in the Journal of Physiology, which have extended over several years. It is not too much to ay that these researches of Mr. Langley upon secreting glands ive him a claim to occupy the highest rank as a physiological nvestigator.

The other most important researches which Mr. Langley has published have been-(1.) Upon the central nervous system, ncluding especially an investigation into the anatomical changes which result from central lesions; (2.) Upon the sympathetic neryous system, and particularly a number of researches, based ipon physiological methods, into its peripheral distribution to nvoluntary muscle and glands. Mr. Langley's eminence in hose branches of physiology to which he has mainly devoted his attention is universally admitted, and has been publicly recogized by his having been requested more than once by international assemblies of physiologists to investigate and report on lifficult cases submitted to them (vide "Transactions of the nternational Medical Congress," 1881, and "Proceedings of he Physiologica! Congress at Basel," 1890).

Prof. François Marie Raoult, of Grenoble (DAVY MEDAL). For his researches on the freezing-points of solutions and on he vapour pressures of solutions.

Sir Joseph Dalton Hooker, F.R.S. (DARWIN MEDAL). Although the regulations relating to the award of this medal direct that it is to be treated rather as a means of encouraging young naturalists to fresh exertion than as a reward for the lifeong labours of the veteran, there would seem to be a special appropriateness in awarding it to one who was intimately Associated with Mr. Darwin in the preparation of he "Origin of Species." That no one was more closely Associated than Sir J. D. Hooker with Mr. Darwin in the work is abundantly proved by the following passage in the ntroduction to the "Origin of Species" :-"I cannot, however, et this opportunity pass without expressing my deep obligaions to Dr. Hooker, who, for the last fifteen years (1844-59), as aided me in every possible way by his large stores of knowedge and his excellent judgment."

NOTES.

MR. W. FLINDERS PETRIE has been appointed to the chair f Egyptology, founded at University College, London, under he will of the late Miss Amelia B. Edwards. He hopes to egin his new duties soon after Christmas, and to undertake the ollowing work :-(1) Lectures on current discoveries, on history, nd on the systematic study of Egyptian antiquities; (2) lessons n the language and philology of Egypt; (3) attendance in the brary on fixed days for the assistance and direction of students orking there; (4) practical training on excavations in Egypt. THE American Philosophical Society, as we have already ated, proposes to celebrate next year the one hundred and ftieth anniversary of its foundation. It has now been arranged at reunions will be held at the Hall of the Society in Philaelphia from May 22 to 26, 1893, "at which papers may be fered by title by such delegates as may honour the Society with eir presence.

THE foundation stone of the new buildings of the Durham ollege of Science, Newcastle, will be laid by Lord Durham on {onday, December 5.

MR. EDGAR R. WAITE, curator to the Leeds Philosophical Society, has received from the Government of New South Wales the appointment of assistant curator in the Australian Museum at Sydney, where he will have special charge of the reptile and fish sections. The Yorkshire Post says that at Leeds Mr. Waite has in many ways actively identified himself with local scientific research and studies, having for some years been, in conjunction with Mr. Denison Roebuck, responsible for the secretarial work -an honorary position-of the Yorkshire Naturalists' Union, and also editor of the Naturalist.

ON November I an industrial school which seems likely to be of good service was opened at Lucknow by Sir Auckland Colvin. It is intended to provide a suitable education for children of the artizan class-an education which comprises instruction in reading and writing, arithmetic, elementary mechanics, physics, and drawing, the whole being in subordination to manual training in the workshop, under skilled instrucManual training will for the present be confined to carpentry, but ultimately training in iron and other metal work will be added to the curriculum. Drawing will be taught to every pupil from the outset.

tors.

VARIOUS members of the department of biology in connection with Columbia College, New York, are now delivering lectures which are addressed especially to persons who desire to keep abreast of the later advances in biology without entering any of the technical courses. The subjects of the lectures are the history of the theory of evolution; the cellular basis of heredity and development; the origin and evolution of fishes; and Amphioxus and other ancestors of the vertebrates.

THE so-called "Boxing Kangaroo" now being exhibited at the Westminster Aquarium is a fine male of Macropus giganteus There is, no doubt, a certain amount of humbug in attributing "boxing" qualities to this animal, but it is very interesting to find that a member of the low Mammalian order, "Marsupialia," can be so well trained and instructed.

THE weather during the past week has remained very dull in all parts of the country, with occasional fog in London and other places, while some heavy rain has fallen in the north and west. The anticyclone which for some time past had been situated over the eastern portion of the United Kingdom gradually dispersed, and the distribution of pressure became favourable to the passage of cyclonic disturbances across the country. Towards the close of the period an area of very high pressure formed to the southward of our islands, the barometer reading 30 ̊5 ins. and upwards, while to the north of Scotland it was more than an inch lower. Under these conditions strong westerly winds became general, and gales were experienced on our exposed coasts. Temperature was at first mild and very uniform over the whole country, there being generally little difference between the day and night readings, while the air was very damp. On Tuesday, however, the thermometer fell several degrees, with some snow and hail in Scotland and Ireland. The Weekly Weather Report shows that for the period ending November 26 rainfall was deficient in all parts of the country except the south of Ireland, where more than twice the average amount fell. Bright sunshine was considerably below the mean in all districts, except in the north of Scotland, where there was 22 per cent. of the possible amount, while the Channel Islands had 16 per cent. It ranged from 3 per cent. in the south-west of England (where the amount quoted for the previous week should have been 20) and midland counties, to I in the east of England and less than o'5 in the north-east of England.

On the 18th ult. Captain H. Toynbee, late Marine Superintendent of the Meteorological Office, delivered a lecture before the Shipmasters' Society on "Weather Forecasting for the British Islands." The chief object of the lecture was to explain

how a careful observer in the British Islands may form a good judgment of the coming weather. The lecturer showed, with the aid of diagrams, the tracks followed by storm centres, with reference to the conditions of areas of low and high pressure. The reason why storms usually proceed in a north-easterly direction across or skirting these islands was explained as owing to the high barometer generally to be found in the Atlantic in the vicinity of the Azores, while in the neighbourhood of Iceland there is a region where the barometer is generally lower than in the space surrounding it. The storms generally advance so as to leave the low pressure on their left, and the high pressure on their right-moving round the south and east sides of the prevailing low pressure. Considerable stress was laid upon the importance of observing the cirrus clouds, the different motions of which, in conjunction with the indications of the barometer, are useful guides both as to the approach of a storm and the track along which the centre is moving. Several illustrations of these facts were given by the lecturer, who also gave many valuable hints as to what may be learnt from the published daily weather charts.

THE Leeds Naturalists' Club seems to be in no hurry about the publication of its Transactions, those for the year 1890 having only just been issued. The volume, however, has been prepared with great care, and shows that much good work is being done by the Club. Among the contents is a most interesting abstract of a lecture by the Rev. Edward Jones on relics found in Yorkshire caves. Reference was made to the cave at Kirkdale, near York, and the Victoria Cave of Settle, both of which have been well worked and have given valuable results; but attention was directed mainly to the cave found at Elbolton or Thorp, which is situated ten miles north of Skipton and two miles from Grassington. Through the energy of the president and members of the Skipton Natural History Society, this cave, which has been handed over to them, has been worked with great earnestness, and many bones have been turned up. Human remains, repre senting some thirteen bodies, have been found in an excellent state of preservation. These human beings must have been buried there, as they were all found in a sitting position, with the knees brought under the chin. The cave, however, was not used only as a burial-place, for the remains of charcoal fires, burnt bones, and pieces of pottery have been found. At the time when the lecture was delivered, the excavations had not revealed anything older than the Neolithic period. Among the finds are several specimens of bones of bears, red deer, foxes, dogs, badgers, grizzle and brown bears, &c. Some time after the delivery of the lecture the members of the Club made an excursion to this interesting cave, which was explored for a distance of a hundred feet, and to a vertical depth of thirty feet. The visitors saw many stalactites and stalagmites in course of fcrmation, and the osseous remains of animals, including some now extinct. Mr. Jones pointed out the former location of several human skeletons.

MR. J. W. TOURNEY contributes to Science (November 11) an excellent paper on cliff and cave dwellings in Central Arizona. He refers especially to dwellings in cliffs rising a hundred feet or more above Beaver Creek, which flows into the Verde river. In the perpendicular walls of one of these cliffs is a well-preserved ruin known as Montezuma's castle. It is midway between the rim of the cliff and the bed of the stream, and is neither house nor cave, but a combination of the two. Not accessible from the summit of the cliff, it can only be reached from below, and even here not without the use of a ladder, which, if short, the climber must pull up from one ledge to another in making the ascent. The entire front is of artificial walls built of large, flat pieces of limestone, with openings here and there for doors and windows. The rooms are small, only about five feet to the ceiling. Generally a small opening

two or three feet in diameter connects one room with anothe and a small orifice in the ceiling gives access to the room ab The openings in the ceilings are never directly under one height of one story. The floors are mostly of flat stones other, so that any one who might stumble could only fal ported on timber cut from the surrounding mountains. M of the timbers are still sound. The rooms all show consi able skill in their construction. Those in the rear are di dungeon-like caves hollowed from the solid rock, and are ar the abode of thousands of bats, which fly about in great bers when disturbed by visitors. A few miles above M zuma's castle, on the opposite bank of the creek, a conspic cone-like mountain rises a few hundred feet above the surro

ing country. The summit is a narrow rim enclosing a crate some three hundred feet in diameter and with nearly per dicular walls.

hundred feet upon the dark-blue water of a small lake in Standing on the rim one can look down. and of unknown depth, is known as Montezuma's wellb bosom of the mountain. The lake, a hundred yards in diamer the steep sides of the crater are a number of caves, which one time were the abode of man. A few are natural, but t greater number are the result of human effort. The rin crowned with the fallen walls of an ancient ruin more th hundred feet long. Far down the mountain-side, below level of the water in the crater, the outlet of the well flows in between an opening in the rocks. This stream is large constant, and at present is used to irrigate a ranch in the val below. Ages ago the builders of caves and castles utilized same stream to irrigate portions of the neighbouring valley.

THE fourth volume of "Reports from the Laboratory the Royal College of Physicians, Edinburgh," edited by J. L Tuke and D. Noel Paton, has just been published. The w completed in the Laboratory during the past year was so l that an account of the whole of it could not be included in the present volume.

A LARGE dirigible balloon is being constructed (La N informs us) at the military balloon works at Chalais-Me under the direction of Commandant Renard. It will be sin in form to the La France of 1884-5, but longer; meas about 230 feet in length and 43 feet in its greatest diameter. a new arrangement of motor it is expected to be able to m headway against air-currents not exceeding 40 feet per sec (or 28 miles an hour). The motor is not fully described, bi will act either with gasoline or the gas of the balloon, giving effective force of 45 horse-power on the shaft. The total we of machinery, with supply of gasoline, &c., will be aborti kilogrammes (or 66 lbs.):per horse power. Previously t not been possible to make petroleum motors with a less we than 150 to 200 kilogrammes per horse-power. The screw be in front, and a large rudder behind; the former will about 200 turns per minute. The first experiments balloon are to be made in the early spring.

DR. HEYDWEILER, of Würzburg, has constructed a 1a mirror electrometer for high potentials (Zeitschr. für li“ It is a kind of torsion-balance with bifilar suspension, charged bodies being a sphere and a ring. The attract between the two, when at different potentials, is zero what sphere is at the centre of the ring, and also when it is infin removed. Hence at some intermediate distance it is a mum. In the instrument as constructed there are two sp of 2 cm. diameter attached to the ends of a conducting barb in the form of an S. The combination is suspended in 1 zontal plane by two brass wires o'r mm. thick attached to? middle of the bar. Two brass rings 10 cm. across are fixed vertical position such that the spheres can be made to co

h their centres. ce of 3'1cm., this being a little less than the distance of ximum attraction. The deflections are indicated by those of irror carried by a thin glass rod attached to the curved arm ow, and the motion is damped by a vane immersed in some etable oil. The tangents of the angle of deflection are protional to the differences of potential to within o'9 per cent., ween the scale readings o'05 and 04. The instrument is t adapted to potentials ranging from 6000 to 60,000 volts, but 1 potentials above 35,000 it is best to immerse it entirely in

In the zero position the spheres are at a dis

AN account of a series of experiments to determine the temature of the flame of water-gas is given by Mr. E. Blass, of en, in Stahl und Eisen. The instruments employed were borgh's air pyrometer, Chatelier's electric pyrometer, Hart- | in and Braun's telephonic pyrometer, and others by Siemens, ger, and Ducretel. It was found that Chatelier's formula the variation of the specific heat of water vapour and other es at high temperatures was practically reliable. The tematures of combustion were taken for various proportions of and gas, beginning with a large excess of the latter. With 8 cubic metres of air to one of gas, the temperature was 5°C. Calculated according to the old formula this would ve been 521. Allowing for variation of specific heat, the oretical value becomes 409. For 0 714 of air, the temperae was 1170, for 4'18 it was 1218, for 9'79 it was 655, and for proportion of air just sufficient for combustion the flame perature was 1169°.

A NEW "shortened telescope,” constructed by Dr. R. Stein1, is described in the Zeitschr. für Instr. for November. The nciple resembles that adopted by Dallmeyer and Dr. A. Stein1 in their telephotographic objectives. A negative system is oduced between the object-glass and the eye-piece, thus in asing its equivalent focal length. If a be the focal length of objective by itself, r its distance from the negative lens, and magnification times that produced without the negative s, the total length of the tube is given by l=r+m (a − r). a telescope actually constructed on this system, the objectss had a focal length of 16 2 cm. Its distance from the rest surface of the negative lens was 12 cm., the equivalent al length 60 8 cm., and the total length 278 cm. Hence the gnification was 3'75 times that obtained by using the objecalone. In this case, then, a magnification of 22 diameters s obtained with an effective aperture of 4 cm., a total length 278 cm., and a one-inch eye-piece. If the same magnification illumination had to be obtained by a long-focus objective, length would have to be 6. 8 cm. Thus the length is reduced more than one-half without the usual disadvantages of short scopes and eye-pieces of high power.

CCORDING to a writer in the Pioneer Mail of Allahabad, thatch on Burmese houses gives a tempting shelter to snakes, cially during the rains, and many of the occupants of the ses would be surprised if they knew the number of snakes share the shelter of their roof on a rainy night. One night fficer was wakened up by a noise in his room; and by the of a lighted wick, floating in a tumbler of oil, he made out two combatants were disputing the possession of the small in the centre of the bedroom. The belligerents turned be a snake and a rat, that somehow had jostled against other in the tiny tenement.

VALUABLE report on the geology of north-eastern Alabama adjacent portions o Georgia and Tennessee, by C. WilHayes, has been published as a Bulletin of the U.S. ogical Survey. Mr. Hayes explains that in writing the

report he has tried to keep it as free as possible from technical terms, and, without sacrificing scientific accuracy, to present the facts in such a way as to make them intelligible to the largest possible number of readers in the region under consideration. Many details which would be of interest to the geologist have been purposely omitted, and only those which were considered essential are given. It is expected that the atlas sheets covering this region will shortly be published by the U.S. Geological Survey, and supply the details to those specially interested which are omitted from the report.

A SECOND edition of Prof. Oliver J. Lodge's "Modern Views of Electricity" has been published by Messrs. Macmillan and Co. A new chapter on recent progress has been added.

A VOLUME on "The Pharmacy and Poison Laws of the United Kingdom" has been issued from the office of The Chemist and Druggist. It contains also a brief account of the pharmacy laws in force in Australasia, Canada, and Cape Colony.

MR. CHARLES E. MUNROE, Torpedo Station, Newport, Rhode Island, U.S.A., has completed the manuscript of the The second part of his index to the literature of explosives. first part was issued in 1886. The second will be issued in pamphlet form if an adequate number of subscriptions is obtained.

MESSRS. FRIEDLÄNDER AND SON, Berlin, send us the latest of their lists of the books which they offer for sale. It is a list of works relating to ornithology.

Upon

PENTA-IODIDE and penta-bromide of cæsium, together with several other penta-halogen compounds of the metals of the alkalies containing mixed halogens, have been isolated by Messrs. Wells and Wheeler, and are described by them in the current number of the Zeitschrift für Anorganische Chemie. Cæsium pentaiodide, CsI5, is obtained in an impure form when the crystals of the tri-iodide of cæsium, CsIg, previously obtained by Prof. Wells and described in our note of February last, vol. xlv. p. 325, is treated with hot water, or when solid iodine is treated with a hot solution of cæsium iodide. Either of these processes produce it in the form of a black liquid, which solidifies in the neighbourhood of 73°. The tri-iodide of cæsium, moreover, which is only sparingly soluble in alcohol, is found to be much more readily soluble when a quantity of iodine, corresponding to two atoms for each molecule of the tri-iodide, is added. cooling, crystals of the penta-iodide of cæsium are deposited. Remarkably well-formed crystals are obtained upon evaporation of a more dilute solution over oil of vitriol. The crystals are black and the faces extremely brilliant; they sometimes attain a diameter of a centimetre. They belong to the triclinic system according to Prof. Penfield, by whom they have been measured. They are at once distinguished from crystals of iodine by their form and brittleness. They melt at about 73°. When exposed to the air they lose iodine about as rapidly as crystals of free iodine. These crystals are anhydrous, and yield analytical numbers agreeing with the formula CsI. The pentabromide of cæsium may be similarly obtained by agitating a concentrated solution of caesium bromide with a large excess of bromine. When such a mixture is allowed to stand at a low temperature the excess of bromine slowly evaporates and the penta-bromide separates in the form of a dark red solid substance. Cæsium penta-bromide CsBrg, is a very unstable substance, losing bromine rapidly at the ordinary temperature. Anothe interesting compound is cæsium tetrachloriodide, CsCI, which was obtained by dissolving forty grams of cæsium chloride in mixture of six hundred cubic centimetres of water and two hun. dred cubic centimetres of concentrated hydrochloric acid, adding

thirty grams of iodine, and then saturating the liquid with chlorine gas. The temperature was raised slightly during the operation, and upon subsequent cooling the compound CSC,I was deposited in the form of pale orange-coloured prismatic crystals belonging to the monoclinic system. The compound is only slightly soluble in water, but, with a little loss due to decomposition, may be recrystallized from that liquid. It is, however, quite stable in the air, and only decomposes upon heating, thereby producing the tri-halogen compound, CsCl,I, fusing at 238°, the melting-point of this latter compound. A similar compound, containing rubidium instead of cæsium, RыCI, may be obtained in like manner in large orange-coloured tabular crystals, likewise belonging to the monoclinic system, but of different habitus to the crystals of the cæsium compound. An analogous compound containing potassium, KCII, was prepared so long ago as the year 1839, by Filhol. Messrs. Wells and Wheeler finally describe sodium and lithium salts of this description, both of which, however, contain water of crystallization. They are

represented by the formulæ NaCl,1.2H2O and LiCl,I.4H,O. Both crystallize well, the former in rhombic prisms; the latter, however, is so extremely deliquescent that measurements of the crystals have not been obtained.

THE additions to the Zoological Society's Gardens during the past week include two Common Marmosets (Hapale jacchus) from South-east Brazil, presented by Mrs. Comolli; an Otter (Lutra vulgaris) British, presented by Mr. Frederick Collier; a Black-backed Jackal (Canis mesomelas, jv.) from South Africa, presented by Miss Thornton; a Common Jackal (Canis aureus, ?) from Fao, Persian Gulf, presented by Mr. W. D. Cumming, C. M.Z. S.; two Short-headed Phalangers (Belideus breviceps, 89) from Australia, presented by Capt. S. M. Orr; a Lemur (Lemur) from Madagascar; six Crab-eating Opossums (Didelphys caucrivorus), four Ypecha Rails (Aramides vpecha) from South America, a Green-cheeked Amazon (Chrysotis viridigenalis) from Columbia, a Yellow-cheeked Amazon (Chrysotis autumnalis) from Honduras, purchased; a Nilotic Monitor (Varanus niloticus) from Africa, received in exchange; two Shaw's Gerbilles (Gerbillus shawi) born in the Gardens.

OUR ASTRONOMICAL COLUMN.

COMET HOLMES (NOVEMBER 6, 1892).-The elements and ephemeris of this comet have been the subject of much computation during the present month. The first result obtained gave a place resembling in many particulars that of the long-sought. for Biela comet; but owing to an error in one of the observations, the corrected elements stated otherwise. The current number of Astronomische Nachrichten (No. 3129) gives four different systems of elements which have as yet been deduced, and it is quite worth while to produce them here, showing also the difference between the observed and reduced places for each in particular :

Elements, Berlin M.T. 1892.

1892.

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The latest information about the elements is that which has originated from Prof. Kreutz, who has found elliptic elements for the comet; he also says that the elements indicate that perturbations have taken place on account of the comet's proximity to the planet Jupiter. The elements are reduced from the three

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Further observations of this comet are reported (2 rendus, No. 21). At Algiers, MM. Trépied, Rambard, found its position on November 15, at 8h. 53m. 418. Ap mean time, to be: App. R. A. oh. 43m. 22:28. Apr. +37 43′ 39. The corresponding values found at Lyca G. Le Cadet at 8h. 47m. 33s., Paris mean time, were R. A. oh. 43m. 22 72s. App. Decl. + 37° 43′ 59 comet presented a bright nebulosity in the form of an e segment with its axis directed in the position angle length and breadth both being 10'. The northern edge are rounded and well defined. At the focus of the ellipse a densation could be distinguished, about 20" broad, w prolongation inclined to the axis of the ellipse. An atte calculating the elements of the orbit has been made la Schulhof. The slow motion of the comet renders this tas difficult. Among the various systems of elements tenar fixed there is only one which fairly agrees with all obser In this the excentricity is as small as 0.355386, so that probably be possible to follow the comet throughout is with the most powerful instruments. The other elemers determined are: =0°0′ 39′′ 1, & = 328° 32′ 40′′ ́7, ¿ — 20 204 and log g 0'360966.

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At Bordeaux, M. F. Courty succeeded in photography brighter portions of the comet on November 13, with hour's exposure. Another photograph, taken by MM. F2 Prosper Henry at Paris, was presented to the Academy Tisserand. It was obtained on November 14, with the photographic equatorial. The exposure lasted two hours. a very fine photograph, showing a well-defined and circular contour. The nucleus is bright, excentric and lerg out. Several stars can be seen through it. There is except the lengthening of the nucleus, which does not beyond the limits of the nebulosity.

A BRIGHT COMET.-A telegram from Kiel states that W. R. Brooks has discovered a bright comet. As dete: at Cambridge, U.S., its place was, on November 2 16h. 446m. Cambridge M. T.

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ASTRONOMICAL INSTRUMENTS UP TO received a circular signed by Dr. L. Ambronn, of the G Observatory, and Herr Julius Springer, publisher in setting forth the contents of a work which they pro publish with regard to the general principles, construction methods of using astronomical instruments in general a book, of course, to be of the greatest value to must be completely done, but any one who is acquaint the compiler and publisher mentioned above will be s each will do his share thoroughly and honestly. In cons such a compendium of instruments as this is proposed we might say it would be impossible for one man to do for the present state of the feintechnik has reached sac pitch and the branches of astronomy are so numerous, the an undertaking would simply be out of question object of this circular, besides stating the lines on w work will be written, is to request the co-operation of all tories. Astronomical science, especially the theoreti owes much, as we all know, to German workers, so th rely on a good response being given to this request.

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