is considerable. Thallium has three oxalates, much resembling those of the potassium series; their solubility, however, increases (instead of decreasing) as the oxalic factor accumulates. The normal oxalate dissolves in 68 parts of water at 15°, and in II of boiling water. The density is 6:31. On heating, it behaves like plumbic oxalate. The crystals of this salt belong to the clino-rhombic system, but are quite unrelated to any of the corresponding potassic or ammonic oxalates hitherto described. The plane of the optic axes is parallel to the plane of symmetry; the double refraction is very energetic. Hydro-thallous oxalateTIHCO + Aq. crystallises in the clino-rhombic system; but its primitive form is reconcilable with that of hydro-potassic oxalate. The specific gravity is 3971. It is soluble in 19 times its weight of water at 15, and in less than its weight of boiling water. There is also an anhydrous salt, whose primitive form is an oblique rhomboidal prism, likewise incompatible with the potassic salt. In both, the double refraction is energetic, and the acute bisectrix positive: but, in the former, the plane of the optic axes is parallel to the plane of symmetry; in the latter, it is normal to that plane. In the former, the proper dispersion is strong, with p< ; in the latter, it is weak, with p > v. The oxalateTIC2O1+3H,С„O ̧ + Aq, ("quadroxalate "), is closely akin to the corresponding potassic salt, both in composition and geometrical form. It shows a powerful double refraction. The plane of the optic axes is almost normal to the base. The proper dispersion of the axes is decided, with p<; the acute bisectrix is negative, and very oblique to the base. The crystals are very fragile.

Thallous picrate is anhydrous. Its colour is yellow, when prepared with but once cooling; but, by Deville's method, this is gradually modified to a vermilion-red. At 150° the dry red salt is soon transformed into the yellow modification. Thallous picrate is less soluble than potassic picrate, one part of it requiring 280 parts of water at 15°, while potassic picrate requires 245. Its density is 3039. Even a temperature of 270 fails to decompose it, but at 300° it detonates with violence. The red crystals are clino-rhombic; they have a vitreous lustre, and the plane of their optic axes is parallel to that of symmetry. The mean value of the index of refraction is B = 1827 (for the yellow line of sodium).

Reduction of Cupric Salts by Tannin

E. PALLUCCI has pointed out that tannin in all its forms reduces cupric oxide in alkaline solution, and forms a red precipitate of cuprous oxide, just in the same way as glucose does; and that the neglect of this circumstance has led to many errors in the estimation of sugar and vegetable juices, and especially in the valuation of the must of the grape : for this liquid contains the tannin derived from the skins of the grapes; and consequently, if the quantity of sugar contained in it is determined by that of the cuprous oxide thrown down, without regard to the reducing power of the tannin, the sugar in the must, and therefore also the alcohol which it is capable of yielding by fermentation, will be over-estimated. This source of error may, however, be casily eliminated by first treating the liquid under examination with basic lead acetate, which completely precipitates the tannin; the glucose may then be estimated in the filtrate.

The importance of attending to this matter in saccharimetric researches will be evident, when it is remembered that tannin is a substance very widely diffused in the vegetable kingdom; and that many vegetable substances, in which sugar is frequently sought for, contain at certain stages of their growth a quantity of tannin two, three, four, or even five times as great as that of their sugar; the greater number of fruits, not excepting the grape, belong indeed to this category. Other substances besides tannin, as for example gallic acid, pyrogallic acid, and many colouring matters, including that of wine, are also capable of reducing the alkaline cupric solution; but all these, as well as tannin, are completely precipitated by basic acetate of lead.-[Ann. di Chem. app. alla Med., Sept. 1869, p. 132.]

In the preparation of quinine and cinchonine, a black, tarry substance is found in considerable quantity. This product, the quinoidine" of commerce, contains a number of cinchona alkaloids, but is not used to any great extent in medicine. MM. Henry, Duguet, and Perret have much increased its value by converting the alkaloids into picrates, thus forming a mixture which can be used with advantage as a very cheap and efficient febrifuge.

GEOLOGY

The Tithonian Stage

PROFESSOR PICTET has communicated to the Swiss Society of Natural Sciences a most interesting report, containing a detailed discussion of a question which has lately acquired much importance, namely, the limitation of the cretaceous and jurassic periods. The Tithonian beds (Titonische Etage) of Oppel, as is well known, occupy a sort of intermediate position between the great jurassic and cretaceous series of deposits, and they have been referred by different authors sometimes to one and sometimes to the other of these great formations. Thus, Professor Oppel himself considered that his Tithonian stage brought the jurassic period a step forward in time, whilst M. Hébert regarded the deposits studied by him as carrying the lower part of the cretaceous formation further back. Of late years these doubtful deposits have been detected in many places, scattered from the Carpathians to the Mediterranean, through Italy, Switzerland, France, and Spain.

Professor Pictet considers that wherever these beds occur, the arrangement of the strata is in accordance with the following sectional view :

1. Neocomian stage proper.

2. Valangian stage and marls with Belemnites latus. 3. Berrias limestone.

4. Tithonian stage.

5. Bed with large specimens of Aptychus (Kimmeridgian). 6. Jurassic fauna with Ammonites tenuilobatus.

The question to be settled is where, if anywhere, in this section the line of division between the jurassic and cretaceous formations is to be drawn, between 3 and 4, between 4 and 5, between 5 and 6, or finally through the middle of 4, dividing it into a jurassic and a cretaceous Tithonian.

The Stramberg limestone, which the author regards as nearly identical with the limestone of the Porte de France and Aizy, contains 55 species of Cephalopoda, of which 50 have been described as new by Zittel, whilst the other 5 have their analogues in the cretaceous period. This would seem to be in favour of the cretaceous nature of this bed; but the Brachiopoda, which have been thoroughly worked out, tell a different tale of 38 species 26 are new, I belong to the jurassic period, and 1 (Terebratula janitor, Pict.) is common to this deposit and that of the Porte de France. It appears, however, that the strict contemporaneity of these fossils is somewhat doubtful, inasmuch as Zittel has found that the molluscan fauna of Stramberg (omitting Cephalopoda and Brachiopoda) is nearly identical with those of Wimmis and Mount Salève, which have been hitherto regarded as Corallian. But neither at Wimmis nor at Mount Salève does Terebratula janitor occur, nor are any of the Cephalopoda of Stramberg found there, so that it is possible the Stramberg deposit consists of two beds, of which the newer contains the above-mentioned Cephalopods and Terebratula janitor, and the older corresponds with the Swiss deposits at Wimmis and Mount Salève the latter might then be the highest term of the jurassic series, and the upper Stramberg bed the lowest of the cretaceous, thus carrying the divisional line through No. 4 of the above section. M. Coquand has found the fauna of Terebratula moravica, which is also that of Wimmis and Mount Salève, occupying deposits in Provence which are covered by beds containing Kimmeridgian and Portlandian Ammonites, and therefore evidently jurassic. From the consideration of these facts the author infers that there have been in different regions two different orders of succession. In one (Provence, Saleve, Wimmis,) the stages are nearly in conformity with those which occur in the rest of France, and the limits of the jurassic and cretaceous periods appear to be clear. In the other, included between the Carpathians and Italy (with a portion of the French Alps, &c.), the Tithonian stage prevails upon the confines of the two great periods.

By an investigation of the paleontology of the beds thus characterised as forming the Tithonian stage, Professor Pictet arrives at the following divisions in ascending order :I. The fauna of Ammonites tenuilobatus.

2. The fauna of the inferior Tithonian, known principally from Rogoznik, the blue marble of the Apennines, and probably the Tyrolese limestone with Terebratula diphya.

3. The fauna of the upper Tithonian or Stramberg limestone (Terebratula janitor).

4. The lower Neocomian stage, especially the Berrias limestone (Terebratula diphyoides).

Jurassic characters predominate in Nos. 1 and 2; No. 3 is rather cretaceous; hence the divisional line, if drawn at all, will fall between Nos. 2 and 3. But the author is of opinion that there is no necessity for drawing this line, and he remarks that the whole of the four stages are combined by strong palæontological analogies. Species pass from 1 to 2, from 2 to 3, and from 3 to 4; Nos. 2 and 3 especially, which would be separated by the line of demarcation of the two periods have about onethird of their species in common. This line would therefore be a very feeble one, and we should have to admit that in this Tithonian basin at any rate the separation of the cretaceous from the jurassic periods is singularly compromised.

[We have given so long an analysis of the argumentative part of Professor Pictet's paper, that we cannot refer to his concluding remarks, except to say that they contain some important observations on the method to be followed in geological investigations.]

PHYSIOLOGY

Reaction of Nerve-Substance. FUNKE some years ago affirmed that nerve, like muscle, became acid after work, and at death. In this he was supported by Heidenhain, and opposed by Ranke and others. He now reasserts his former statement, using the delicate reagent cyanin instead of litmus, and finds strong proofs of the correctness of his views. The matter is not unimportant, as it is one of the few bases on which rests the broad general assertion that nervous [and mental] action is accompanied by material changes. [Centralbt. med. Wissensch. 1869, No. 46.]

Action of Muscarin.

SCHMIEDEBERG and KOPPE have published an account of the pharmacy and physiological action of muscarin, the active constituent of agaricus muscarius (amanita muscaria). This mushroom poison seems to be not unlike the Calabar bean in its action, and belladonna is in many respects antagonistic to it.

MAX SCHULTZE's Archiv für Microscopische Anatomie v. 4, contains, among other papers:

"Ueber die Nervenendigung in der Netzhaut des Auges bei Menschen und bei Thieren." Von Max Schultze. Description of certain fibrilla ensheathing the rods and cones of the vertebrate retina, and believed by Max Schultze to be the real nerve endings. An important memoir, tending to harmonise the results obtained from the study of invertebrate and vertebrate eyes. "Untersuchungen über den feineren Bau des Pancreas." Von Dr. Giovanni Saviotti aus Turin. Description by a pupil of Köllicker's, of fine intercellular passages in the pancreas, similar to those discovered by Hering in the liver. "Die haaretragenden Sinneszellen in der Oberhaut der Mollusken." Von Dr. W. Flemming in Rostock. A detailed description of certain fimbriated cells in the epidermis of acephalous mollusks, and gasteropods, not wholly unlike, and occuring in the midst of, ciliate cells, but believed by Flemming to be organs of sense. 'Ueber Radiolarien und Radiolarien-artige Rhizopoden des süssen Wassers." Dr. Richard Greeff, Privatdocenten in Boon. Description of species of Clathrulina, Acanthocystis, and several species of new genera Astrodisculus, Hyalolampe, with discussion of their habits, anatomy, &c.

Von

PFLUGER'S Archiv, ii. 9 and 10, contains:—“Quecksilberluftpumpe." Von II. Busch. A modification of the mercurial pump employed by Pflüger. The chief novelty is the occlusion of the orifices of the various parts by means of mercurial shoulder cups. "Das Unterscheidungsvermögen des Geschmacksinnes für Concentrationsdifferenzen der schmeckbaren Körper." Von Fr. Keppler in Tübingen. Keppler found it easiest to distinguish by taste variations of strength in "saline" solutions, less easy in "acid" or "sweet" liquids, and least easy in "bitter" liquids, though bitter substances (such as quinine) are those which require the smallest quantity to make a definite impression. "Ueber die Abhängigkeit der Leber von dem Nervensystem." Von E. Pflüger. Nebst Tafel II. und III. An important memoir in which Pflüger extends to the liver, the observations already made by him on the salivary glands and pancreas, affirming the direct continuation of the nerve fibres with the secreting cells. "The hepatic cell is a nucleated swelling of the axis cylinder of a nerve.' Contains also many other points of interest, touching the structure of the liver, and strongly supports the views of Dr. Beale. "Ueber den Einfluss des

Cyangases auf Haemoglobin nach spectroscopischen Beobachtungen." Von E. Ray Lankester. A short note affirming, in opposition to some German observers, that cyanogen forms a definite compound with Haemoglobin analogous to those of carbonic oxide, &c. "Zur Kenntniss der Wirkungen des Weingeistes.' Von Dr. F. Obernier, Privatdocent und Assistenzarzt der medic. Klinik zu Bonn. A somewhat polemic paper contesting the views of Bouvier, &c., noticed in NATURE, No, 2.

SOCIETIES AND ACADEMIES

LONDON

Royal Society, November 30.-Anniversary Meeting.-The President delivered his annual address, in which he touched upon several points of interest. One of the first subjects to which he drew attention was the Royal Society's Catalogue of Scientific Papers, the printing of which proceeds satisfactorily. He remarked: "While the aid to be derived to scientific research from the index according to authors' names is fully recognised, there can be no doubt that the value of the Catalogue will be greatly enhanced by the fulfilment of the second part of the plan announced in the preface, namely, by the publication of an Alphabetical Index of Subjects. The preparation of such an "Index Rerum" as is contemplated, has been for some time a subject of anxious, as well as careful, consideration by the Library Committee, and they have at length arrived at what, they have reason to hope, will be a most satisfactory solution of the question through a communication with Professor Julius Victor Carus, of Leipsic, who they found would be willing himself to undertake the task. I am happy to announce that the Council, acting on the recommendation of the Library Committee, have entered into a very satisfactory arrangement with Professor Carus, who will be able to commence his labours in the ensuing spring. From the well-known scientific accomplishments of Professor Carus, and his extensive experience in the peculiar work to be performed, as well as the confidence which will be reposed in him by all acquainted with the nature of the undertaking and interested in its success, we may consider the Society most fortunate in securing his services." The Meteorological Department of the Board of Trade, superintended by a Committee of the Royal Society, was next referred to; it is stated to be making good progress. Concerning the great Melbourne telescope the President remarked: "Its performance since erection does not appear to have given the same satisfaction at Melbourne that it did at Dublin; but the defects complained of may arise partly from an imperfect knowledge of the principles of the instrument and inexperience in the use of so large a telescope, partly from experimental alterations made at Melbourne, and partly from atmospherical circumstances. Those who are acquainted with the difficulties which Sir J. F. W. Herschel experienced at the Cape, will not be surprised that they should be felt at Melbourne to a much greater extent, on account of the far greater size of the speculum. But I have no doubt that if the instrument be kept in its original condition and as carefully adjusted as it was at Dublin, it will perform as well in ordinary observing weather. The high impression of its power produced by the trials which were made of it when at Dublin, is maintained by a sketch of a portion of the Great Nebula near ŋ Argus, made by M. Le Sueur during two nights in June last. Some change in this nebula from the time when it was described by Sir J. F. W. Herschel had been indicated by Mr. Powell and other observers, though with instruments so much inferior in power to his 20-foot reflector, that little reliance could be placed on them; however, here the evidences of change are indisputable. The peculiar opening in the nebula which Sir John Herschel has compared to a Lemniscate, is still very sharply marked, but its shape and magnitude have altered. Its northern extremity is opened out into a sort of estuary; one of the remarkable con. strictions seen in 1834 has disappeared, and the other has shifted its place. Two stars which were then exactly on the edges of the opening are now at some distance within the bright nebulosity; the nebula has become comparatively faint near Argus. Another remarkable change is the formation of a V-shaped bay south and preceding the Lemniscate, whose edges are so bright that if it had then existed it could not have been overlooked in the 20-foot reflector. Another feature, which, however, was perhaps not within reach of that telescope, is an oval which M. Le Sueur describes as full of complicated dark markings and pretty bright nebular filaments." The angular magnitude of the

changes which have been observed, is so great as to suggest a strong probability that this nebula is much nearer to us than the stars which are seen along with it. It may be also noticed that M. Le Sueur saw nothing to make him believe in any development of stars in addition to those seen by Sir J. F. W. Herschel." The Council of the Society believes that an attempt to encourage and aid spectroscopic researches is an object in full unison with the highest purpose of the Royal Society's existence; and they have, therefore, after most careful deliberation, resolved to act on this conviction. A telescope of the highest power that is conveniently available for spectroscopy and its kindred inquiries is being constructed, and will be entrusted to such persons as, in their opinion, are the most likely to use it to the best advantage for the extension of this branch of science; and, in the first instance, there can be but one opinion that the person so selected should be Mr. Huggins. The President said: "The execution of this project was much facilitated by the receipt of £1,300 from a bequest made to the Society by the late Mr. Oliveira; and in the beginning of the year proposals were received from the chief opticians of the time, of which that of Mr. Grubb was accepted last April. The conditions proposed were, that the object-glass of the telescope should be of 15-inches aperture, and not more than 15-feet focus, that the arrangements of its equatorial should be such that it could be easily worked by the observer without an assistant, and that the readings of its circles could be made without leaving the floor of the observatory. Mr. Grubb was fortunate enough to secure two discs which had been exhibited by Messrs. Chance at the French Exhibition. They are of firstrate transparency, and as the construction which has been adopted admits of the lenses being cemented, this object-glass will transmit an unusual portion of light. The respective indices of the glasses were determined by making facets on their edges at an angle of 60", and observing spectral lines through the prisms thus formed with a spectroscope of such magnitude as to admit of their being placed on its table. The distinctness with which even faint lines are seen through 12 inches of the glass is a most satisfactory proof of its purity and clearness. From these Professor Stokes computed the curves for the lenses, and his numbers were almost identical with those which Mr. Grubb had obtained. I may mention that some fears had been entertained that the equality of curvature in the adjacent surfaces might call up a ghost, if the lenses were used uncemented, and that this has been tried and no such effect was visible. Subsequently a rather novel addition has been made, bearing upon the radiation of heat from the stars. An object-glass intercepts so much of the heatrays that, to economise the infinitesimal effect which is expected, a metallic mirror is more promising. The equatorial is, therefore, at the suggestion of Mr. De la Rue, provided with the means of changing the 15-inch achromatic for an 18-inch reflector; and this has been accomplished by means notable for their facility and their safety. The instrument will be ready for trial in December of the present year." The rest of the address referred to the recent dredging expedition. The President then proceeded to the award of the Medals. The Copley Medal was awarded to M. Victor Regnault for the second volume of his "Relation des Expériences pour déterminer les lois et les données physiques nécessaries au calcul des Machines à Feu," including his elaborate investigations on the Specific Heat of Gases and Vapours, and various papers on the Elastic Force of Vapours. The President remarked that the name of M. Victor Regnault had been associated for the last quarter of a century with the most refined and delicate experimental inquiries connected with the measurement of heat. The amount of labour involved in his researches upon the specific heat of simple and compound bodies, upon the dilatation of gases and vapours, upon the comparison of the airthermometer with the mercurial thermometer, upon the elastic force of aqueous vapour, upon the determination of the density of gases, and upon hygrometry, must excite the astonishment of all who could estimate the difficulty of the problems attacked, the precision of the results attained, and the fundamental character of the data which he had determined. The Council has awarded a Royal Medal to Sir Thomas Maclear, Astronomer Royal at the Cape of Good Hope, for his measurement there of an arc of the meridian. The President re

minded his audience that our sole knowledge of the figure of the southern hemisphere rested on the arc of the meridian measured by La Caille, and now remeasured and extended by Maclear. The original measurement, notwithstanding the well-known ability of the great astronomer under whose superintendence it was executed, had not commanded confidence. Maclear's

The

arc has an amplitude nearly four times as great as that of La Caille, and is, on this account, as well as on account of the greater accuracy in detail, far more deserving of confidence. The degree which is derived from it is 1,133 feet shorter than that of La Caille; and as La Caille's is 1,051 longer than that given by the spheroid, which, according to Airy, represents the average of northern arcs, it is evidently a near approximation to the truth. This is even more distinctly shown by the close agreement of the latitudes computed from the geodetic measurements with those given by the sector-that of the north extremity being o"4 in defect, that of the south extremity o":5 in excess.-A Royal Medal has been awarded to Dr. Augustus Matthiessen, F.R.S., for his researches on the electrical and other physical properties of metals and their alloys. President remarked that these researches embraced the determinations of the specific gravities, the expansion due to heat, the thermo-electric properties, the electric conducting-power, and the effects of temperature upon the electric conductingpower. Dr. Matthiessen's investigation of the electric conducting-power of commercial copper had resulted in very great improvement of the conducting.power of the copper wire used in submarine telegraphy. Closely connected with this branch of his researches were the investigations which Dr. Matthiessen carried out for the Electrical Standard Committee of the British Association, of which he was one of the most active members. The resistance-coils issued by that Committee, which had been very generally adopted as standard instruments, were all constructed of an alloy of platinum and tin, which, after a long series of experiments, Dr. Matthiessen recommended as specially fitted for that purpose. Under the auspices of the British Association, Dr. Matthiessen undertook, a few years ago, the investigation of the chemical constitution of cast-iron, and of the influence exerted upon the physical properties of that metal by the several other elements which generally occur in association with it. He had lately elaborated a method of producing pure iron, which promised to be fruitful in interesting and important results in the hands of himself and the other chemists with whom he has been associated in this inquiry. Dr. Matthiessen's researches published in the Philosophical Transactions, on the action of oxidising agents upon organic bases and on the chemical constitution of narcotics (the latter investigation having been conducted in conjunction with Professor G. C. Foster), furnished proofs of the success of his labours in organic chemistry. His researches were distinguished as well for their diversity as for their uniformly complete and trustworthy character. The following officers are elected for the ensuing year :-President: Sir Edward Sabine, L.L.D.; Treasurer: W. Allen Miller, M. D., LL.D. Secretaries: W. Sharpey, M.D., LL.D.; and G. Gabriel Stokes, LL.D. Foreign Secretary: Professor W. Hallows Miller, LL.D. The other members of the Council are: Frederick Currie, M. A.; Warren De la Rue, Ph. D.; Sir P. de M. Grey Egerton, Bart.; Professor W. H. Flower, F.R.C.S. Eng.; William Huggins; J. Gwyn Jeffreys; John Marshall, F.R.C.S. Eng.; Augustus Matthiessen, Ph. D.; Captain Henry Richards, R. N.; the Marquis of Salisbury, M.A.; C. W. Siemens; John Simon, F. R. C.S.; Archibald Smith, M. A.; Professor H. I. Stephen Smith, M.A.; Professor John_Tyndall, LL.D.; and Professor Alexander W. Williamson, Ph.D.

Royal Astronomical Society, November 12.-First Meeting of Session. Mr. Warren De la Rue, F. R.S., vice-president, in the chair. The Chairman opened the meeting by referring to the illness of Admiral Manners, the president of the society, an announcement which was heard by all present with much regret. The minutes of the last meeting having been read and confirmed, and upwards of 100 presents announced, Mr. Carrington read a paper descriptive of his observatory near Farnham, Surrey, and of a variety of ingenious contrivances for securing its efficiency, and especially the correct measurement of time. Mr. Carrington intends observing with an alt-azimuth, which he has designed to ensure the comfort and consequent accuracy of the observer. The telescope-tube rotates freely on its axis, which is always horizontal; it carries the vertical circle, and in front of the object glass a right-angled prism, the front face of which may be directed on any object by the axil rotation of the tube of the telescope. The Astronomer-Royal was then invited by the Chair. man to describe his recent invention of a method of correcting the chromatic dispersion of the atmosphere. He described the various contrivances by which that object might be secured.

Mr.

The simplest method of all was the employment of a series of different angles suited to the altitude of the object; but as this has some inconveniences Mr. Simms suggested the employment of an adjustable prism, as, for example, adjustable tilting of the field-glass of the eye-picce. This method, though simple, introduced undesirable optical effects. It appeared necessary, therefore, that the correction should be effected outside the eye-piece; and the best method seemed to be the combination of a convexo-concave and a convexo-plane lens, the convexity of the latter fitting into the concavity of the former, and admitting of being rotated within it, so as to vary the corrective effect according to the state of the air or the position of the object observed. Mr. Cayley, F.R.S., afterwards noticed that the desired effect could be secured by combination of two prisms, in one of which there is a convex, and in the other a concave cylindrical surface of the same curvature; when these cylindrical surfaces are made to rotate on each other, the opposite faces of the combination can assume any relative position between parallelism and an inclination equal to the sum of the refracting angles of the component prisms. Both contrivances are described in Brewster's Optics; and it is satisfactory to consider that the troublesome effect of atmospheric chromatic dispersion can be corrected effectually by contrivances so well known.-The AstronomerRoyal then invited the attention of the meeting to a proposition which had been made by the American observers, that the passage of Venus over the solar chromosphere should be observed by spectroscopists during the transit of 1874, for the purpose of determining the solar parallax. Mr. Huggins described the methods of observation available for the purpose. Proctor expressed doubts as to the accuracy of the suggested method, remarking that the phenomenon, to be observed to the best advantage, would require other stations than those selected for observing internal contacts, and that the effect of parallax, by causing Venus to cross different parts of the chromosphere, as seen from different stations, would be a fatal objection, since we have no reason for believing that the chromosphere is uniformly deep. He remarked also that we are not merely ignorant of the exact point at which Venus will cross the sun's limb, but of the angle at which her path will be inclined to the limb. Mr. Stone intimated his belief that we should find a number of difficulties cropping up around the new method, which might render observations as unsatisfactory as those made in 1769 upon the internal contact.-After some remarks by the Chairman upon the advantages of applying photography to the coming transits, a paper by Mr. Alexander Herschel, on the November meteors, was read to the meeting. Mr. Herschel shows that there is evidence of a triplicity in the meteoric stream, since in 1868 three distinct maxima were observed in England, America, and China. In 1867 and 1866 also, three maxima were observed, but they were not separated by so wide an interval. Mr. Proctor then read a paper on the application of photography to the transit of 1874. The paper was illustrated by a chart exhibiting the passage of the earth through the shadow-cone of Venus, and showing along what lines stations should be placed, at any time, so that the relative displacement of Venus might be along a radial line of the sun's disk. By so selecting stations (or times) he remarked, the whole question would become simply one of parallax, no appreciable error would come in through misplacement of the fiducial cross-lines, and so photography would do the best work it was capable of, for determining the sun's distance. In reply to Mr. Proctor's comments on the importance of the coming transits, Mr. Stone pointed out the close correspondence of the results he has deduced from the observations in 1769., with the various other determinations of the sun's distance, and expressed his doubts whether any important improvement can be made in 1874 and 1882. Mr. Birt then read a paper on the spots which are visible on the floor of the lunar ciater Plato, of which he exhi bited an interesting drawing. Mr. Browning read a paper on the changes of colour which the equatorial belt of Jupiter has recently exhibited; and indicated the importance of a careful series of observations directed to the determination of any periodicity which may exist in these changes. In describing the American photographs of the eclipse of last August, Mr. De la Rue remarked that they confirm the evidence already afforded by his own observations in 1860, and those of Major Tennant in 1868, that the corona, in part at least, is a solar phenomenon. The meeting closed with an announcement on the part of the Chairman, that a medal had been struck at the Imperial Mint of France in honour of Hind, Goldschmidt, and Luther, on the occasion of the discovery of the hundredth planetoid in 1868.

Geological Society, November 24.-Prof. T. H. Huxley, LL.D., F.R.S., President, in the chair.-Robert Arnold Barker, M.D., Civil Medical Officer, Cachar, Bengal, was elected a Fellow of the Society. The following communications were read :-(1), On the Dinosauria of the Trias, with observations on the Classification of the Dinosauria," by Prof. Huxley, LL.D., F.R.S., President. The author commenced by referring to the bibliographical history of the Dinosauria, which were first recog He nised as a distinct group by Hermann von Meyer in 1830. then indicated the general characters of the group, which he proposed to divide into three families, viz. :

:

I. The MEGALOSAURIDA, with the genera Teratosaurus, Palæosaurus, Megalosaurus, Poikilopleuron, Lalaps, and probably Euskelosaurus;

II. The SCELIDOSAURIDE, with the genera Thecodontosaurus,
Hylaosaurus, Pholacanthus, and Acanthopholis; and
III. The IGUANODONTIDE, with the genera Catiosaurus,
Iguanodon, Hypsilophodon, Hadrosaurus, and probably Ste-
nopelys.

He

Compsognathus was said to have many points of affinity with the Dinosauria, especially in the ornithic character of its hind limbs, but at the same time to differ from them in several important particulars. Hence the author proposed to regard Compsognathus as the representative of a group (Compsognatha) equivalent to the true Dinosauria, and forming, with them, an order to which he gave the name of ORNITHOSCELIDA, The author then treated of the relations of the Ornithoscelida to other Reptiles. He indicated certain peculiarities in the structure of the vertebrae which serve to characterise four great groups of Reptiles, and showed that his Ornithoscelida belong to a group in which, as in existing Crocodiles, the thoracic vertebrae have distinct capitular and tubercular processes springing from the arch of the vertebra. This group was said to include also the Crocodilia, the Anomodontia, and the Pterosauria, to the second of which the author was inclined to approximate the Ornithoscelida. As a near ally of these reptiles, the author cited the Permian Parasaurus, the structure of which he discussed, and stated that it seemed to be a terrestrial reptile, leading back to some older and less specialised reptilian form. With regard to the relation of the Ornithoscelida to birds, the author stated that he knew of no character by which the structure of birds as a class differs from that of reptiles which is not foreshadowed in the Ornithoscelida, and he briefly discussed the question of the relationship of Pterodactyles to birds. He did not consider that the majority of the Dinosauria stood so habitually upon their hind feet as to account for the resemblance of their hind limbs to those of birds, by simple similarity of function. The author then proceeded to notice the Dinosauria of the Trias, commencing with an historical account of our knowledge of the occurrence of such reptilian forms in beds of that age. identified the following Triassic reptilian-forms as belonging to the Dinosauria:-Teral, saurus, Platavsauris, and Zandledon from the German trias; Thecodontosaurus and Palæosaurus from the Bristol conglomerate (the second of these genera he restricted to P. cylindrodon of Riley and Stutchbury, their P. plutyodou being referred to Thecodontosaurus); Cladyiden from Warwickshire; Deuterosaurus from the Ural; Ankistrodon from Central India; Clepsysaurus and Bathygnathus from North America; and probably the South African Pristerosaurus. --Sir Roderick Murchison, who had taken the chair, inquired as to the lowest formation in which the bird-like character of Dinosaurians was apparent, and was informed that it was to be recog nised as low as the Trias, if not lower.-Mr. Seeley msisted on the necessity for defining the common plan both of the Rep tilia and of the ordinal groups before they could be treated of in classification. He had come to somewhat different conclusions as to the grouping and classification of Saurians from those adupted by the President. This would be evident, in so far as concerned Pterodactyles, from a work on Ornithosauria which he had just completed, and which would be published in a few days. -Mr. Etheridge stated that the dolomitic conglomerate, in which the Thecodont remains occurred near Bristol, was distinctly at the base of the Keuper of the Bristol area, being beneath the sand. stones and marls which underlie the Rhætic series. There were no Permian beds in the area. He regarded the conglomerates as probably equivalent to the Muschelkalk. It was only at one point near Clifton that the Thecodont remains had been found. — Prof. Huxley was pleased to find that there was such a diversity of opinion between Mr. Seeley and himself, as it was by discus. sion of opposite views that the truth was to be attained. He