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Melicerta. I coiled one of these round the wall of a deep cell, and thus brought into the field of view, at once, more than a hundred living Melicerte of all ages and sizes, and all with their wheels in vigorous action; a display never to be forgotten.

Such a tank, so stocked and managed, would probably enable a patient and ingenious observer to decide several other points, about which we are, at present, in ignorance: to say whether the same individual always lays eggs of the same kind, or whether it may lay now female eggs, now male, now ephippial eggs; and to say what determines the kind of egg that is to be laid; whether it is the age of the individual, or the supply of food, or temperature, or sexual intercourse that is the potent cause.

It would, too, hardly be possible for the male, to escape the observation of a naturalist, who possessed a tank in which were hundreds of Melicerta: and the male is as yet almost unknown. Judge Bedwell found in the tubes of the female, in winter, a small Rotiferon resembling the supposed male, that I had seen playing about M. tubularia; only the former had a forked foot, and sharp jaws that were at times protruded beyond the coronal disc. Its frequent occurrence in the tubes in various stages of development, and the nonchalance with which the female suffered it to nibble at her ciliary wreath, inclined the observer to conclude, that the animal was the long sought-for male. Unfortunately it was only observed when in motion, so that its internal structure was not made out; and the matter therefore still rests in some doubt.

No doubt it is a strong argument that the female would probably suffer nothing but a male to take such liberties with her; but it would seem, from the following account, that it is possible for such freedoms to be pushed too far.

Mr. W. Dingwall, of Dundee, was on one occasion watching a male Floscule circling giddily round a female, and constantly annoying her by swimming into her fully expanded coronal cup. Again and again she darted back into her tube, only to find her troublesome wooer blocking up her cup, and sadly interfering with, what to a Floscule is, the very serious business of eatingfor these animals will often eat more than their own bulk in a few hours. It was clear at last that the lady would not tolerate this persistent interference with her dinner; for when-after waiting, rather a longer time than usual, closed up in her tube-she once more expanded, only to find him once more in his old position, she lost all patience, and effectually put an end to his absurdities, by giving one monstrous gulp, and swallowing her lover. It will not surprise you to hear that he did not agree with her, and that after a short time she gave up all hope of digesting her mate, and shot him out into the open again, along with the entire contents of her crop. He fell a shapeless, motionless lump; the two score and ten minutes of a male Rotiferon's life cut short to five; but, strange to say, in a second or two, first one or two cilia gave a flicker, then a dozen; then its body began to unwrinkle and to plump up; and, at last, the whole corona gave a gay whirl, and the male shot off as vigorous as ever, but no doubt thoroughly cured of its first attachment.

I have taken Melicerta ringens, as an example of what yet remains to be done, even with an animal which is as common in a ditch, as a fly is in a house; but almost every other Rotiferon would have done equally well, for there is scarcely a single species, whose life-history has been thoroughly worked out.

To me, natural history in many of its branches seems to resemble a series of old, rich mines, that have been just scratched at by our remote ancestors, and then deserted. Our predecessors did their best with such feeble apparatus as they had; it was not much, perhaps, but it was wonderful that they did it at all with no better appliances; and it irks me to think that we, who are equipped in a way which they could not even dream of, should turn our backs on the treasures lying at our feet, and go off prospecting in new spots, contented too often with a poor result, merely because it is from a new quarter.

Besides, the love of novelty is a force too valuable to be wasted on a mere hunt for new species in any one group of animals, especially unimportant ones. It should rather be used to make us acquainted with the more striking forms of many groups. Let us have no fear of the reproach of superficial knowledge; everyone's knowledge is superficial about almost everything; and even in the case of those few who have thoroughly mastered some one subject, their knowledge of that must have been superficial for a great portion of their time. Indeed, the taunt is absurd. I can imagine that a superficial knowledge of law,

or surgery, or navigation may bring a man into troubl what possible harm can it do himself, or anyone else, th content with knowing five Rotifera instead of tive be And yet if any naturalist were to study only F Philodina, Copeus, Brachionus, and Pedalion, it would gw the greatest possible pleasure, as well as an excellent notion of the whole class. Let any tyro at the seaside wi ways and growth of a Plumularia, or of a rosy feather e knowledge of the groups to which they belong could not be dignified even with the term "superficial "—"lin"punctiform" would be more appropriate; but the ple that he would derive from such a study, could not be g. counting the number of animals that he had examin would depend on the man himself; and might. I should imagine, far exceed that derived by the study of a hundred the number of forms in books; especially when such a had been undertaken, not from a natural delight in it, be some irrelevant reason, such as to support a theory, to a an opponent, to earn a distinction, or to pass an examin In truth that knowledge of any group of animals, which rightly be called superficial when contrasted with the knot. of an expert, is often sufficient to give us a satisfactory acqu with the most interesting creatures in it; to make with processes of growth and reproduction too marvellos imagined by the wildest fancy; and to unfold to us the h creatures who, while possessing bodily frames so unlike .. that we are sometimes at a loss to explain the function parts, yet startle us by a display of emotions and glimmerings, that raise a score of disquieting questions.

Moreover, there is another excellent reason why we sh confine our attention to one subject; and that is, that e most ardent naturalist must weary at times of his special po Variety is the very salt of life; we all crave for it, a natural history, at all events, we can easily gratify the craveg we are tired of ponds and ditches, there are the rock poob south-western shores, and the surface of our autumn root of oar-weed torn at random from a rocky ledge, 1 whelk shell from deep water, a rough stone from low wate the rubbish of the dredge, -each and all will afford us deng amusement. It is wonderful, too, what prizes lurk in things, and how often these fall to beginners. The very time that I tried skimming the sea with a muslin net, I. piece of green seaweed off the muslin, intending to the away; but, seeing a little brown spot on it, I dropped the (not a square inch) into a bottle of sea-water, instead. the brown speck started off and darted wildly round the It was too small to be made out with the naked eye, bai ti time I had brought my lens to bear, it had vanished. 1. all over the bottle, and could see nothing, neither with the nor without it. I was half inclined to throw away the but, as I was certain that I had seen something in it two before, I corked up the bottle and took it home. looked at it, there was the little brown creature flying ab wildly as ever. I soon made out, now, that I had caugh tiny cephalopod-something like an octopus-and wild a “ I fished it out, and dropped it into a glass cell. dropped the water from the pipette into the cell; but thes itself had vanished again; I could not see it either to the or the cell. I was not going to be tricked again; so I' the cell under the microscope, and there was my prize: less, but for its panting; and watching me, as it were microscope with its big blue-green eyes. It was almost less, and was dotted at wide intervals with very miast: spots, set quincunx fashion-spots absolutely invisible sharpest unaided sight.

When

As I looked it began to blush-to blush faint or deeper orange, then orange-brown; a patch of color another there, now running across one side of the b fading away, again to appear on a tentacle; till at last, covered from its alarm, each black spot began to quie rapid expansions and contractions, and then to spread on 5 varying tints, till its wavering outlines had met the opof its neighbouring spots; and the little creature, reg. colour and its courage at the same moment, rushed off on«! in a headlong course round the cell.

I was the merest beginner when I saw this, but I had 1-luck, knowing nothing whatever about it, and never ha the subject a thought, to see, with my own eyes, how ca cuttlefishes are protected by their loss of colour, and 1980 how the loss takes place.

doubt the sea-side of our south-western coasts-I mean recka, not the thundering shores of Bude and Bos "-is a e for microscopists; but there is no need that we should * far aheld. Our inland woods, our lanes and pastures, well to us a thousand beauties and wonders. The scarlet nel will show its glorious stamens, the flowers of the sort glow like a costly exotic; wild mignonette will rival fantastic shape the strangest orchid; the humblest grass tuft of glistening crystals; the birch and salad-burnet out their crimson tassels; the Jungermanns will display romic volcanoes, the mosses unfold the delicate lacework ⚫denty urns. But the time would fail me to name one f those sources of wonder and delight that lie all around - most of which, as in the case of the Rotifera, contain points on which we are all happily ignorant, and * in the best of all possible conditions for deriving endasure and instruction from them. Besides, my time and your mest. I think, be drawing to a close; I would then only **ore suggest, that we should not only explore for ourselves pastures new "-no matter how imperfectly-but that and encourage those, who can be our most efficient guides, ze us with the main results in the simplest language. one of the most charming subjects, that can interest -eings, admits of being so treated; and there can be no Pason why the Muse of Natural History (for no doubt there Muse) should resemble that curious nymph among the , whom Mr. Michell found lying under the moss of at tree, half smothered in a heap of her cast-off skins, he types of successive classifications, and abandoned

ture.

ay, however, books in such matters are of little importnd names and classifications of still less: both these deed, are of ephemeral interest; they are the pride of and the reproach of to-morrow. It is to the living themselves that we must turn, fascinated not only with auty and their actions, but with the questions which the lation of them perpetually provokes, and very rarely in the long procession of the humbler creatures, who can here life first develops into consciousness, and why it does here consciousness first stretches beyond the present so as de the past, and why that happens; or at what point, h, memory and consciousness themselves are lighted up by faint flashes of reason?

Je how nothing now of such matters, and probably we never "I w much; but the mere fact that the study of natural rresistibly draws us to the consideration of these quesives to her pleasant features an undoubted dignity, and he charming companion of our leisure hours to the rank imate sharer of some of our gravest thoughts.

THE TOTAL ECLIPSE.

HE U.S.S. Pensacola arrived at Saint Paul de Loanda on I ember 6, after a voyage of 51 days from New York, made the ports of Horta, Fayal, in the Azores, Nover 23; of Saint Vincent, in the Cape Verdes, November 12, of Saint George's Parish, Sierra Leone, November 18md of Elmina, on the Gold Coast, November 26-28.

ily on landing at Loanda, it was found that the Rio eamer, sailing bi-weekly for Muxima, had left two viously, and that recent washouts along the line of the to de Ferro Trans-Africano made it impracticable for pedon to reach either Muxima or Cunga early enough * sufficient time for mounting and adjusting the instru for the eclipse.

refore at unce decided to locate the Expedition at or - Ledu. Mention should be made here of the courteous of His Excellency the Governor of Loanda, for his heres: in the Expedition, and the facilities he offered The prosecution of the various fields of its work.

did came to anchor alongside H. M.S. Bramble in le bay to the north of Cape Ledo, on the afternoon of -9 December 8. The Eclipse Station was selected in a Furable spot close to the shore cliffs, and the sites of the al instruments were determined before night. for ten days hard work sufficed for getting a large of the apparatus in readiness for the eclipse. I placed bigelow in charge of the direct photoheliograph of nearly

40 feet focal length, and detailed Mr. Davis to assist him. Mr. Jacoby was intrusted with the charge of the time-determinations, and longitude and latitude work. The Bramble was at Cape Ledo on a mission like that of the Pensacola, and attending upon the English Eclipse Expedition in charge of Mr. A. Taylor, F.R.A.S.; and through the courtesy of her commanding officer, Captain Langdon, R.N., advantage was taken of her run to St. Paul de Loanda and return, December 14-17, to make a chronometric determination of the longitude, by comparison with the time at Loanda as determined by Mr. Preston, who was left there by the Expedition for the gravity and magnetic work. Also, on the Bramble's second return to Loanda, on December 23, another comparison was made.

Prof. Abbe was in charge of the meteorological work and of the organization of parties of observers from the ship's company. A large amount of valuable material results from his work.

The mounting and adjustment of the extensive apparatus for the total eclipse, I reserved for myself. A duplex polar axis eleven feet in length had been constructed of six-inch iron tubings, and mounted with great stability. This axis was driven by powerful clock-work of extreme precision, made by Mr. Saegmueller, of Washington. On this single axis was mounted the totality-battery, consisting of 2 Brashear reflecting telescopes of 8 inches diameter, four Clark telescopes of 3, 5, 7, and 8 inches aperture, the second being rigged with an eyepiece enlarging the sun's image to a diameter of 4 inches, the third being used as a high power directing telescope, while the fourth, a photographic doublet with 10 inch back lens, loaned by the Harvard College Observatory, was arranged for a series of twelve exposures, two of which were made through an orthochromatizing screen provided by Mr. Carbutt; two six-inch Dallmeyer rapid rectilinear lenses of 24 and 38 inches focus; one Schroeder triple objective, of 6 inches aperture and 22 inches focus; one Gundlach orthoscope of 3 inches aperture and 21 inches focus ; two flint spectroscopes and one quartz spectroscope loaned by Harvard College Observatory; a duplex photometer of 75 inches focus also provided by Prof. Pickering, and his reversing layer spectroscope for photographing a spectrum trail for fifteen seconds both before and after second and third contacts; a 5 inch Ross lens of 42 inch focus; a 4 inch Spencer objective of 36 inch focus, and a 6:4 inch Merz-Clark objective, both rigged with the means of automatic variation of aperture during totality; and lastly, two duplex cameras provided by Dr. Wright of the Sloane Laboratory of Yale University, for photographic record of the polarization of the corona. In all there were 23 objectives and two mirrors, with their axes adjusted into parallelism.

With the exception of the Gundlach camera, which was reserved for a special investigation of the extreme outer corona, all this apparatus was operated automatically, by an adaptation of the pneumatic organ-valve system of Mr. Merritt Gally, of New York. Exposing shutters were opened and closed, sensi tised plates were exchanged for others as soon as exposed, and all the mechanical movements were accomplished with entire precision. Also, by employing an ordinary chronograph in conjunction with the valve system, the exact time of beginning and end of each exposure became a matter of accurate record.

All this apparatus was brought into operation during the period of total eclipse, and over 300 exposures were made in a period of 3m. 10sec.; but no photographs of the corona were secured, as the sun was completely obscured by clouds. However, the entire success of the pneumatic movements is a result of no little value in view of eclipse work in the future.

In addition to this, a silver-on-glass mirror, of 20 inch diameter and 75 feet focal length, by Brashear, lent to the Expedition by Prof. Langley, was so mounted as to throw an image of the corona up the cliff and just underneath the sun at the time of totality. At the focus a beautiful 10 inch image of the sun was formed, and 20 x 24 inch plates of the highest sensitiveness were in readiness to record the coronal streamers. This unusual apparatus was also rendered inoperative by clouds.

With the direct photoheliograph, however, very gratifying success was secured. Seventy pictures of the partial phases were made before totality, and forty after. The serious obstacles to the operation of so long a tube were successfully overcome by means of a skeleton mounting, a combined form of an equatorial stand and tripod; and Prof. Bigelow's sand-clock enabled the precise and easy following of the sun. The revolving plate holder, of 22 inches diameter, actuated automatically by compressed air, in which the principles of the apparatus of the

National Electric Service Company were employed, was a thorough success. Exposures were made at intervals of six

seconds.

A few hours before the eclipse came on, the Pensacola went out to sea, and stood in the centre of the eclipse-track at the time of totality. Atmospheric conditions were slightly more favourable there than at the main station of the Expedition, and some interesting results were obtained. During totality, however, the clouds were so thick that it is very doubtful whether the true solar corona was seen at all.

The Eclipse Station was completely dismantled by December, 27, and the Pensacola left Cape Ledo on the afternoon of the same day.

Returning to Loanda, it was found that two of the three detached parties of the Expedition sent into the interior to observe the eclipse were unsuccessful on account of clouds. The third has not yet been heard from.

U.S.S. Pensacola, December 31, 1889.

DAVID P. TODD.

SCIENTIFIC SERIALS.

Without

Rendiconti del Reale Istituio Lombardo, December.-Results obtained from Dr. L. Weigert's therapeutic treatment of pulmonary phthisis, by Prof. A. Visconti. Seven patients in various stages of consumption have been subjected to this treatment for the purpose of testing its efficacy. It consists in administering superheated dry air (150° to 180° C.), which is inhaled through a specially prepared apparatus, for which Dr. Weigert claims that it acts directly on Koch's bacillus of tuberculosis. In the incipient stages of the disease satisfactory results were obtained in some respects, such as relief of the cough, greater freedom of respiration, less profuse perspiration, and increased appetite. But it was doubtful whether the germ itself was killed, while in the advanced stages the malady continued its normal development without being perceptibly arrested by the treatment. actually condemning Weigert's method, Prof. Visconti cannot at present regard it as an efficacious remedy against phthisis.-On the determination of the coefficient of dynamic and electromotor produce, by P. Guzzi. The author here describes a method of determining this coefficient, for which he claims certain advantages over that proposed by Dr. J. Hopkinson in the Electrician of December 3, 1886, especially in the case of engines of over 100 horse-power. His method of calculating the yield of the dynamo and electric motors is based exclusively on electric measurements made with safer and more handy instruments than Hopkinson's dynamometers. Two dynamos of about the same type and dimensions are connected together in such a way that one moves the other as motor, as in the Hopkinson apparatus. But instead of communicating to the system the dynamic energy required to maintain it in motion with the velocity and intensity of the normal current, Guzzi's instrument communicates the equivalent electric energy derived from any

external source whatsoever.

Rivista Scientifico-Industriale, December 31, 1889.-Researches on the absorption of hydrogen by iron, and on the tenacity of certain metals after absorbing gases, by Prof. M. Bellati and S. Lussana. It has already been shown by Hughes (NATURE, vol. xxi., 1880, p. 602) that steel and iron immersed in diluted sulphuric acid become very brittle, and that the same phenomenon is produced when these metals are used as negative electrodes in a voltameter. Prosecuting the same line of research, the authors here describe a series of experiments tending to show that the action of electrolytic oxygen on the tenacity of platinum, and of hydrogen on that of copper and zinc, is uncertain; also, that the absorption of hydrogen produces very probably an increase of tenacity in platinum, as it certainly does in iron, but, on the contrary, a diminution in nickel. Nor can these different results be explained by the simple passage of the current, Möbius having already shown that the elasticity of metals is not perceptibly affected by this cause.-Action of arsenate of hydrogen on potassium permanganate, by D. Tivoli. Some experiments are described, from the results of which the author infers that the solution of potassium permanganate is capable of rapidly and completely absorbing arsenate of hydrogen.-S. Giuseppe Terrenzi gives a somewhat complete list of the land and fresh-water mollusks occurring in the Narni district, Umbria. This fauna presents nothing remarkable, all the species being common to other parts of Umbria, and generally to Central

Italy. All are described or mentioned by the Marchese P in his "Etude de la Faune Malacologique terrestre a de l'Italie et de ses îles" (Paris, 1878).

SOCIETIES AND ACADEMIES.
LONDON,

Royal Society, January 30.-"On the Germination
Seed of the Castor-oil Plant (Ricinus communt.
Green, M.A., B.Sc., F.L.S., Professor of Botany -
Pharmaceutical Society of Great Britain. Communic
Prof. M. Foster, Sec. R. S.

The work embodied in this paper deals) with the which, during germination, render the reserve material, w for the use of the embryo, (5) with the forms in which th absorbed by it and the mode of their absorption, and z the parts played in the process by the endosperm an embryo respectively.

A ferment is found to exist as a zymogen in the resting which is readily developed by warmth and weak acids active condition. The results of its activity are the spot of the fat with formation of glycerine and (chiefly t acid. Further changes, brought about by the protuple endosperm cells, form from the latter a lower carbon and unlike ricinoleic acid, is soluble in water and is These changes do not take place in the absence of freeA quantity of sugar also is formed, which appears to hair glycerine as its antecedent.

The proteids of the seed, which consist of globie albumose, are split up by another ferment, with forme peptone and asparagin.

The only products which enter the embryo are a cr acid, sugar, possibly some peptone, and asparagin. C ation of the structure of the cotyledons, which are the t organs, shows that the mode of absorption is always dil,

"Investigations into the Effects of Training Wall Estuary like the Mersey." By L. F. Vernon Harcourt." M. Inst. C. E. Communicated by A. G. Vernon Ha F.R.S.

The present investigations were carried out with a model of the Mersey estuary, from near Warrington to the sea beyond the bar. The experiments were directe. solution of two problems-namely, (1) the influence of in walls in the wide upper estuary on the channel below Live and across the bar; and (2) the effects of training walls a lower estuary on the channel across the bar.

The experiments indicate that, whereas training wail. upper estuary would be injurious, owing to the resultin tion, training walls in the lower estuary would impro depth of the outlet channel; and that such trainin combined with dredging, offer the best prospect of fort direct, stable, and deepened channel across the bar.

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February 6.-"Memoir on the Symmetrical Functions Roots of Systems of Equations." By Major P. A. Mac. Royal Artillery. Communicated by Prof. Greenhill, Ft. The object of the present memoir is the extension tu 1* of algebraical quantities of the new theory of symmetric f which has been developed by the author in regard to a system in vol. xi. and succeeding volumes of the 4 Journal of Mathematics. In the theory of the single the conceptions and symbolism are to a large extent anthr and are based upon the properties of single integra and their partitions into single integral parts. In this set former theory may be regarded as being unipartite.

In the present generalization to the case of m syst quantities the fundamental ideas proceed, not from number, but from a collection of single numbers la to number, weight, degree, part, and suffix, the collectio numbers invariably replaces the single number of the t the single system. In this view the theory of the # *m-partite.

The quantities, to which the symmetric functions rele be regarded as the solutions common to non-home equations each in m variables. Schlafli, in the Vienos 7: tions (Denkschriften) for 1852, added another linear o geneous equation in m variables, and then forming the el

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1 equations, thereby obtained an identity which is antal in the subject. This identity involves those symfunctions which are here termed fundamental, and marks tarting point of the present investigation.

particular, three distinct laws of symmetry are established, generalizations of those established by the author in the rean Journal of Mathematics (vol. xi.). Of these the first are of fundamental importance, and are examined in detail. aling idea in these theorems, as in the whole investigais the "separation" of a partition; the separation bearing an: relation to the partition as the partition to the number section of numbers.

nclusion, the memoir consolidates and largely generalizes her's recent researches alluded to above.

Swary 13.—“ On the Unit of Length of a Standard Scale George Shuckburgh, appertaining to the Royal Society." eral J. T. Walker, R.E., F.R.S.

- determinations of the length of the seconds pendulum, were made in London by Kater and at Greenwich by and are described in the Philosophical Transactions 18, 1829, and 1831, the distance between the upper and ges of the pendulum was measured off on a standard wach had been constructed by Sir George Shuckburgh. ale had not yet been compared with any of the modern tard scales, but it had been preserved with much care with ruments appertaining to the Royal Society.

the autumn of 1888, M. le Commandant Defforges, an r of the French Geodetic Survey, came to England to are in operations for the determination of the difference ule between Greenwich and Paris, and also to determine gth of a French seconds pendulum at Greenwich. He by undertook to comply with a suggestion which was made by me, to compare the portion of Shuckburgh's scale had been employed by Kater and Sabine with one of the 1 metre bars of the International Bureau of Weights and in Paris. The Council of the Royal Society assented, cale was sent across to Paris and brought back again by (ji zgent.

e details and results of the comparison are given in a account by Commandant Defforges, from which it will that the scale was compared with the French metrical ale, N, at the temperature of 48°7 F., at which the disBetween Kater and Sabine's divisions, o and 39'4, of the cigh scale was found equal to 10006245 metre. On 12 to the temperature of 62° F., which was employed by and Sabine, this distance becomes 1'0007619 metre, which alent to 39400428 inches if we adopt the relation 39 370432 inches, which was determined by Colonel C.B., of the Ordnance Survey, and is given in his Die work on the comparisons of standards of length. the actual length of the space o to 39'4 on the Shuckburgh ay be regarded with some probability as differing by not than about o'0004 inch, or, say, the 100,000th part, from tity which the scale indicates.

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hysical Society, February 7.-Annual General Meeting. o. Reinold, F. R.S., President, in the chair.-The reports Council and of the Treasurer were read and adopted. mer stated that there had been a very satisfactory increase e number of members during the year. The number now 360, of whom 80 are Fellows of the Royal Society. the year the Council had proposed to change the time of ag of the Society from Saturday afternoon to Friday 2. The change was adopted by the members by a vote of 30 and had resulted in a larger attendance at the meetings. the year the second part of vol. i. of the translations of ortant foreign memoirs had been issued to the members, and

hoped that a third part would be published early in rent estion, The Council had to regret the loss by death ree well-known members-James P. Joule, Warren de la and Father Perry. A valuable collection of books had ven the Society by the Royal Astronomical Society. the Treasurer's report, it appeared that the balance of the has been increased by 120 during the year. Prof. ef, of Munster, was, at the recommendation of the Council, dan honorary member of the Society. The result of the eketion of officers was declared as follows:-President : WE. Ayrton, F.R.S.; Vice-Presidents: Dr. E. AtkinWalter Baily, Shelford Bidwell, F.R.S, and Prof. S. P. pon. Secretaries: Prof. J. Perry and T. H. Blakesley;

Treasurer: Prof. A. W. Rücker, F.R.S.; Demonstrator: C. V. Boys, F.R.S.; other Members of Council: W. H. Coffin, Sir John Conroy, Bart., Conrad W. Cooke, Major-General Festing, F.R.S., Prof. J. V. Jones, Prof. O. Lodge, F.R.S., Prof. W. Ramsay, F.R.S., W. N. Shaw, H. Tomlinson, F. R.S., and G. M. Whipple. Votes of thanks were then passed (1) to the Lords of the Committee of the Council on Education for the use of the room in which the Society met; (2) to the auditors, Prof. Minchin and Dr. Fison; (3) to the President and officersof the Society for their services during the year.-The meeting was then resolved into an ordinary science meeting. Messrs. E. W. Smith and C. E. Holland were elected members of the Society, and Mr. Sidney Evershed was proposed as a member. -The paper on galvanometers, by Prof. W. E. Ayrton, F. R. S., Mr. T. Mather, and Dr. W. E. Sumpner, was then resumed by Prof. Ayrton. A long table of numbers accompanying the paper, and representing the result of experiments on many galvanometers, was explained. From this it appeared that galvanometers of the D'Arsonval type were exceedingly efficient in proportion to the amount of wire used in the coils. It was for this reason that voltmeters with strong permanent magnets could be made sensitive even with an exceedingly large external resistance in series so as to diminish the power absorbed by the instrument. The space occupied by the wire was so exeedingly valuable that the extra resistance did not too much diminish the sensibility. The most sensitive galvanometers should therefore be made of the permanent magnet type. If, however, the magnetswere to form part of the moving system, as in most galvanometers, the experiments showed that instruments of the Rayleigh, Gray, or Rosenthal type were the best. The coils should be numerous and small, as Mr. Boys had previously shown. As an astatic system of needles sets itself perpendicular to the earth's field, it was recommended that astatic galvanometers should be placed so that the needles pointed east and west. The controlling magnet would then not need to be turned round as it was raised or lowered. It was recommended to calibrate low-resistance ballistic galvanometers for quantity by measuring the deflection for a known current. This obviates the necessity for large condensers or high potentials. The method, although not new, is not described in text-books. In conclusion, Prof. Ayrton asked for information with regard to microscope galvanometers. C. V. Boys, F.R.S., thought that the factor of merit of galvanometers should not be given in scale divisions per micro-ampere under the condition of constant controlling moment. This gave too great an advantage to instruments of the Gray or Rosenthal type. Great sensibility could be obtained by diminishing the moment of inertia of the suspended parts, the practical limit being determined by the trouble due to the silk fibre. Spider lines, when used in place of silk fibres, gave better results. It was possible by using a good suspending arrangement to use needles" long and a period of 20 seconds, and to gain a sensibility far greater than those indicated in the paper. Ballistic galvanometers should be made with needles as light as possible. The method proposed, of winding the central part of the coil in the opposite sense to the rest, would probably not be good, owing. to the unevenness of the field produced. The conclusion come to by the author, that D'Arsonval galvanometers of great sensibility should be made with small coils placed in a very strong field, was one he had himself come to, but had finally abandoned owing to difficulties caused by diamagnetism in the copper and to excessive damping due to Foucault currents. Mr. Swinburne thought that the factor of merit of a galvanometer should be determined differently according as it was to be used for the measurement of current, or quantity, or for null methods merely. He saw no great advantage in making practical instruments proportional. The name D'Arsonval should be dropped, as the instrument denoted by it was invented by Varley years ago. He would like to know the relative sensibility of the telephone and the Lippman galvanometer. Prof. Fitzgerald stated that Lord Rayleigh had shown that the microscope method of observing angular deflections was as sensitive as the ordinary method of mirror and scale, even when only the mirror was used as a pointer, so that if a pointer were attached it would be far more sensitive. The drawback, however, was that it was impossible to distinguish with the microscope between lateral displacements of the needles and the angular motion whose measurement was required. To get over this error it was necessary to read both ends of the pointer, but this was hard to do. Prof. Ayrton replied to the different points raised in the discussion.

Entomological Society, February 5.-The Right Hon. Lord Walsingham, F.R.S., President, in the chair. -The Presi dent announced that he had nominated Mr. J. W. Dunning, Captain H. J. Elwes, and Mr. F. D. Godman, F. R.S., VicePresidents for the session 1890-91.-Mr. F. D. Godman exhibited a specimen of Papilio thoas, from Alamos, Mexico, showing an aberration in the left hind wing. Mr. R. Trimen, F. R.S., remarked that butterflies of the genus Papilio were seldom liable to variation. -Mr. C. G. Barrett exhibited a series of specimens of Phycis subornatella, Dup., from Pembroke, the east and west of Ireland, the Isle of Man, and Perthshire; and a series of Phycis adornatella, Tr., from Box Hill, Folkestone, Norfolk, and Reading; also a number of forms intermediate between the above, taken in the Isle of Portland by Mr. N. M. Richardson. He said that these forms proved the identity of the two supposed species, which he believed were both referable to P. dilutella, Hb. He also exhibited specimens of Hesperia lineola, and a pale variety of it taken in Cambridgeshire; specimens of Epischnia bankesiella, a recently-described species, taken in Portland; and a specimen of Retinia margarotana, H.-S., a species new to Britain, discovered amongst a number of Retinia pinivorana, which had been collected in Scotland.Mr. W. H. B. Fletcher showed a series of Gelechia fumatella, from sandhills in Hayling Island and near Littlehampton, and, for comparison, a series of G. distinctella, from the same places. He also showed a few bred specimens of G. terrella, and a series of preserved larvæ. He stated that on the downs the larva live in the middle of the tufts of such grasses as Festuca ovina and allied species.-Mr. H. Goss read a communication from Dr. Clemow, of Cronstadt, St. Petersburg, on the subject of the coincidence of vast flights and blights of insects during the years 1510, 1757, 1763, 1782, 1783, 1836, and 1847, and the epidemic of influenza. During the year 1889 no unusual activity in the insect world had been recorded. Mr. H. T. Stainton, F. R.S., and Mr. McLachlan, F. R. S., made some remarks on the subject, the purport of which was that there was no connection between epidemics and the occurrence of swarms of insects.-Mr. G. A. J. Rothney communicated a paper entitled "Notes on Flowers avoided by Bees." It appeared, according to the author's observations, made in India, that dahlias were exceptionally attractive, but that the passion-flower was only resorted to by a few species of Xylocopa; and that, with one exception, he had never seen any insects feeding on the flowers of the oleander. Mr. Slater, Colonel Swinhoe, Mr. Trimen, Lord Walsingham, and Mr. McLachlan took part in the discussion which ensued.-Dr. D. Sharp read a paper entitled "On the Structure of the Terminal Segment in some male Hemiptera."-Colonel Swinhoe read a paper entitled "On the Moths of Burma," which contained descriptions of several new genera and 107 new species. Dr. F. A. Dixey read a paper entitled "On the Phylogenetic Significance of the wing-markings in certain genera of the Nymphalide." A discussion ensued, in which Lord Walsingham, Mr. Jenner-Weir, Captain Elwes, and Mr. Trimen took part.

Zoological Society, February 4.-Prof. W. H. Flower, F.R.S., President, in the chair.-The Secretary read a report on the additions that had been made to the Society's Menagerie during the month of January 1890.-A communication was read from Mr. W. K. Parker, F.R.S., containing an account of the morphology of the Hoatzin (Opisthocomus cristatus). The author treated of the early stages of the development of this Reptilian Bird, and its shoulder-girdle, sternum, and hind limbs. A communication was read from Mr. A. D. Bartlett, containing observations on Wolves, Jackals, Dogs, and Foxes. Mr. Bartlett's remarks tended to show that all the varieties of Domestic Dogs owe their origin to Wolves and Jackals, and that the habit of barking has been acquired by, and under the influence of, domestication; also that the Dog is the most perfectly domesticated of all animals. -A communication was read from Mr. G. E. Dobson, F.R.S., containing a synopsis of the genera of the family Soricidæ. The author recognized nine genera, and divided them into two sub-families. New methods of defining the genera were introduced, each genus was briefly characterized, and remarks on certain genera, not admitted in the synopsis (although hitherto generally recognized), were appended. Mr. F. E. Beddard read a paper containing observations upon some species of Earthworm of the genus Perichata.A communication was read from Mr. J. M. Leslie, containing notes on the habits and oviposition of the clawed Aglossal Frog (Xenopus lavis), as observed at Port Elizabeth, Cape Colony, where this species was said to be of ordinary occurrence.-Mr.

Oldfield Thomas read an account of a collection of M from Central Vera Cruz, Mexico, made by a scient he si tion organized by the authorities of the Mexican Museum the superintendence of Dr. F. Ferrari-Perez. The co consisted of about 100 specimens, belonging to 21 = Amongst these, two (a Hare and a Squirrel were desa new, and proposed to be called Sciurus nigr me'in as Lepus vera crucis.

Geological Society, February 5.—W. T. Blanford. F President, in the chair.-The following communicato read :-The variolitic rocks of Mont-Genèvre, by tire J. Cole and J. W. Gregory.-The propylites of the V Isles of Scotland, and their relations to the andes = diorites of the district, by Prof. John W. Judd, F.R.S

EDINBURGH.

Royal Society, January 27.-Rev. Prof. Flint, Viet dent, in the chair.-Prof. Calderwood read a naper on 25 and man's place in Nature. A discussion followed.

February 3.-Sir W. Thomson, President, in the chir William Peddie read a paper on new estimates of distance. He showed that the ratio of the latent vaporisation of a liquid to six times its surface-tension g approximation to the number of molecules per linear that liquid. The liquids water, alcohol, ether, chin carbon bisulphide, turpentine, petroleum, and wood spac according to this method, 50, 52, 30, 15, 19, 30, 40, 2* millions, respectively, of particles per linear centimetr course no stress is to be laid upon the relative values of numbers; the point of interest is the complete agreeme the order of the unknown quantity.-Prof. Tait com a paper by Prof. Dittmar on the gravimetric com water.-Mr. John Aitken read a paper on the number o particles in the atmosphere of certain places in Great Br** on the Continent, with remarks on the relation betwe amount of dust and meteorological phenomena. that dust condenses moisture before the air is saturated. I same number of dust particles per cubic centimetre, th. spheric transparency depends upon the depression of bulb, being large when the depression is large, bat be small before the depression vanishes. Increase of tem:also reduces transparency when the number of particles the same, for increase of temperature means increase of pressure. As a rule, quantity of dust decreases when increases. When calms occur dust accumulates. This.0the radiating power of the air, so that it cools quickivu. forms. Thus a fog may be regarded as a suspendel d.. — dust-measuring instruments intended for use at Ben Nesas exhibited.

PARIS.

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Academy of Sciences, February 10.-M. Hermit chair.-Note on an unpublished memoir of Descartes' in the right of the author to the priority of a discovery in the of polyhedrons, by M. De Jonquieres. Some pas pointed out in the memoir which show that Descartes Les applied the formula F+S=A+2, and furnished the elem the demonstration, hence his name should be assocare. that of Euler as an independent discoverer of the famous -A physical process for the measurement of the inchin the declination-thread of meridian-circles, by M. Hamy. ordinary astronomical methods this value can be determ within half a degree, but using the process described, 1 sible to obtain it within a few seconds. The complete tion will be given in the coming number (January) of the. Astronomique.-Upon the exponential function, by M. A demonstration is given of a relation of the form N+N1+eN,.... +cN=0.

a, b,
., being whole numbers, N, N., Ng,.
cients. Starting with the polynomial function
F()=2(3-4)+(-b)μtis...

the author deduces that assuming (1) to hold

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