for by local environment; constant civil intertribal war being the means of isolating communities, so that no friendly intercourse is held, by reason of which, together with other attendant causes, an incongruity of language may have unknowingly been established. With reference to geology, Mr. Thomson said it was somewhat remarkable that the general geological features of British Papua are in a very considerable degree identical in character with those of Australia, several specimens being coincident with those of the Silurian series from gold-fields in New South Wales, while some of the fossiliferous rocks were obtained from beds of clay similar to those at Geelong and Cape Otway in Victoria. Mineral areas of great value might yet await discovery by the penetrating eyes of British pluck and enterprise in Papua.

SECTION F.

ECONOMICS AND SOCIAL SCIENCE AND STATISTICS. Mr. R. Teece, President, chose for the subject of his opening address, "The New Theory of the Relation of Profit and Wages." Papers were contributed by Mr. Alfred de Lissa, Sydney, on "The Organization of Industry "; by the Hon. N. J. Brown, Tasmania, on "The Incidence of Taxation"; by Mr. H. H. Hayter, Government Statistician, Victoria, on "Disturbance of Population Estimates by Defective Records"; by Mr. A. J. Ogilvy, on "Is Capital the Result of Abstinence?"; by Mrs. A. Morton, Tasmania, on "The Past Attitude of Capital towards Labour, and the Present Attitude of Labour towards Capital"; by Mr. T. A. Coghlan, Government Statistician, N.S. W., on "The Wealth of Australasia"; by Mr. A. J. Taylor, Hobart, on "The Value of Labour in relation to the Production of Wealth regarded from the Standpoint of a Physicist "; and by Mr. E. P. Nesbit, South Australia, on "Insanity and Crime."

SECTION G.

ANTHROPOLOGY.

The Rev. Lorimer Fison, President, said in the course of his opening address that in anthropological study the two main things required were first a patient continuance in collecting facts, and second the faculty of seeing in them what is seen by the natives themselves. But the natural tendency to form a theory as soon as a fact was seized, and looking at facts in savagery from the mental standpoint of civilized man, would lead investigators into fatal mistakes. The best way to gain information was to live with the natives, learn their language, and gain their confidence, or get information from the men living amongst them. References to aborigines, their manners and customs, in books, might be collected and classified by many readers, and thus facilitate investigation. In conclusion he dwelt upon the magnificent and all but untrodden field afforded by British New Guinea and its outlying groups of islands; and two extremely valuable books-the Rev. Dr. Codrington's on "The Melanesian Tribes," and "The Maori Polynesian Comparative Dictionary," by Mr. Edward Tregear, of New Zealand -were recommended for study.

The Rev. Dr. Gill, who has spent thirty-three years as a missionary in the Hervey Islands, read papers on "The Story of Tie and Rie" and "The Omens of Pregnancy," the latter baving reference to superstitions still current in the island of Mangaia.

A paper on "New Britain and its People" was read by the Rev. B. Danks. According to the author, the bush people differ very much from the coast tribes, the latter being evidently invaders and conquerors.

Some interesting details as to Sydney Natives Fifty Years ago," were given by the Rev. W. B. Clarke. Among other papers were the following: "Group Marriage and Relationship" and "The Nair Polyandry and the Dieri-Dieri Pirauru," by the Rev. L. Fison; "The Samoa and Loyalty Islands," by the Rev. S. Ella; "The Cave Paintings of Australia," by the Rev. J. Matthew; "The New Hebrides," by the Rev. D. Macdonald; "The Origin of the Sense of Duty," by Mr. Alex. Sutherland; "Notes on the Taunese," by the Rev. W. Gray.

SECTION H.

SANITARY SCIENCE AND HYGIENE.

Prof. W. H. Warren, of the University of Sydney, gave in his residential address a sketch of sanitary engineering from its earliest days, and then proceeded to discuss the various schemes

which have been proposed for disposing of the sewerage of

towns.

Dr. James read a paper on " Cremation as a Step in Sanitary Reform." Papers were also contributed by Dr. E. Ö. Giblin, on "The Etiology of Typhoid"; by Miss Violet Mackenzie, on "Physical Education and Exercise in Schools"; by Dr. Barnard, on "Infection in Disease"; and by Dr. A. Moulton, on "Sewerage of a Seaside City.'

SECTION I.

LITERATURE AND FINE ARTS.

This Section, although it assembled for the last time at the Hobart meeting, proved to be very popular. The President, Prof. Morris, of the University of Melbourne, referred in his opening address to the subject of Universities in Australia. He urged that it was not wise to multiply Universities. "In this matter," he said, "the law of supply and demand cannot be trusted, if it ever can be in the matter of education; and the Legislatures should be very careful not to permit the promiscuous conferring of degrees. Let them increase teaching facilities as much as generosity may make possible; do not lower the standard, as at least in the higher education competition does. In America there are five or six degree-giving Universities to every million inhabitants, and a degree by itself has no value. If Australia were one country, as it ought to be, two Universities would probably be quite enough, or, better still, even one, but it would need to be arranged somewhat on the pattern of the University of New Zealand, with teaching bodies in different places, but one uniform standard of examination for each degree. This would lead to emulation between the different teaching Colleges, and would surely have happy results. Unfortunately Australia is not one, and at present it looks as if, in spite of the wishes of the people, our absurd divisions were likely to continue. Yet it is worth consideration whether the Universities might not agree upon a common standard, and arrange that the courses in the Universities of the different colonies should be parallel and homogeneous. Educated men should be the first to show that the day of discord is over, and to welcome the arrival of unity and co-operation."

66

Among the contributions to the proceedings of this Section were papers on Elementary Science in Primary Schools," by Mr. James Rule, senior inspector of schools, Tasmania; "Secondary Education in Australia," by Mr. Percy A. Robin; and "The Rationale of Examinations," by Mr. F. J. Young. A Committee was formed to establish a Home Reading Union for Australia.

SECTION J.

ENGINEERING AND ARCHITECTURE.

Mr. C. Napier Bell, President, referred in his opening address to sanitary engineering. In Australia, he said, the best attention of engineers should be devoted to sanitary engineering; first, to cleanse the towns, and second, to save the sewage to irrigate the land. On this subject Australian engineers should pause before copying the practice of Europe, which, enjoying an abundant rainfall, has never felt the same necessity for irrigation, and has had abundant stores of fossil manure to draw upon. Water irrigation was even more important, and he foresaw for engineers a noble task in providing irrigation for Australia. After dealing with the irrigation works of the older countries, he touched upon the importance of mining and electrical engineering. Then he remarked the neglect of warming and ventilation by architects and engineers, and argued that in the climate of Australia the art of cooling must certainly become as important as that of heating. In conclusion, he explained the necessity for sound theoretical and scientific knowledge in the engineer, and said that if the people of the colonies would entertain the honourable ambition, once more popular than now, of being remembered to the distant ages of the future, they must emulate those mighty peoples of the past who left imperishable records of their life in the ruins of their vast public works.

Among the papers read in this Section was one by Mr. Edward Dobson, on The Evidence for the Prevalence of Human Habitations in Prehistoric Times." It was devoted to showing that, whilst rectangular forms prevailed in the early buildings of the East and in North America, the circular form had prevailed through Africa (with the exception of the Nile Valley) and through Switzerland and Northern Europe, in

THE DRAPER CATALOGUE OF STELLAR SPECTRA.

THE Observatory of Harvard College has played a prominent part in the development of astronomical photography. It was here, on July 17, 1850, that Prof. Bond obtained the first photographic image of a star, and from that time forward much important work has been accomplished, culminating in the Draper Catalogue of the photographic spectra of 10,347 stars. The progress of this latter branch of astronomical work has been but slow, and it is a remarkable fact that its extraordinary development during the last few years has followed from the revival by Prof. Pickering of the method of observation first employed by Fraunhofer in 1824. Accounts of the progress of the work have been published from time to time, and have been noticed in our columns. A complete account of the 'Preparation and Discussion of the Draper Catalogue," which has recently been issued, forms vol. xxvi., part i., of the Annals of the Astronomical Observatory of Harvard College.

The earlier attempts to photograph the spectra of the stars were made with spectroscopes having slits, although, from the time of Fraunhofer, it was recognized that a slit was not an essential part of a stellar spectroscope. In 1863, Dr. Huggins succeeded in photographing the spectrum of Sirius, but none of the characteristic lines were visible. In 1872 Dr. Henry Draper, to whose labours in the field of astronomical photography the Draper Catalogue forms a fitting memorial, succeeded in obtaining a photograph showing four lines in the spectrum of Vega. Dr. Huggins again took up the work, and since 1879 has obtained a considerable number of photographs, none of which, however, appear to show anything approaching the amount of detail now obtainable. In all these attempts the spectroscope was attached to the eye end of the telescope, so that the image of the star was formed on the slit, a cylindrical lens being interposed in order to give width to the spectrum.

In the method which has been so pre-eminently successful, the slit and collimator, which form an essential part of an ordinary spectroscope, are dispensed with, the rays from a star already possessing the necessary parallelism and its image being almost a perfect slit without length. It is only necessary, therefore, to fix a prism in front of the objective of a telescope, and to introduce some means of widening the spectrum, to obtain a complete stellar spectroscope. For eye observations the necessary width is obtained by the use of a cylindrical lens in conjunction with the eye piece of the telescope. For photographic work, the prisms are so arranged that the spectrum lies along a meridian, and it is then only necessary to allow the | driving clock to be slightly in error to obtain a widened spectrum. The clock error must of course vary according to the magnitude and declination of the star.

The great advantage of the slitless spectroscope" depends upon the fact that every scrap of light passing through the object glass is utilized; with the ordinary spectroscope it will seldom happen that all the light passes through the slit, and it is further reduced by absorption in the lenses and prisms of the spectroscope. Further, on account of the large focal length of the telescopes employed, a high dispersion is obtained even with a prism of small angle; and a large number of spectra can be photographed at a single exposure. Prof. Pickering has photographed the spectra of as many as 260 stars on the same plate, and the labour involved in the construction of the Draper Catalogue has thus been enormously reduced. Indeed, the whole of the 10,347 spectra were photographed on 585 plates. The improvement in photographic processes has undoubtedly done much to facilitate the work, but it is lamentable that the "wholesale" method was not applied twenty years ago, for even with the less perfect processes then in vogue, our knowledge would have been much advanced.

An important feature of Prof. Pickering's work is the method of enlargement of the negatives, which renders the fainter lines clearly visible. "The negative is covered by a diaphragm, having a slit in it which is made to coincide with the spectrum. An image is then formed by an enlarging lens in the usual way. A cylindrical lens is next interposed near the enlarging lens, with its axis perpendicular to the lines in the spectrum. The width of the latter may thus be increased indefinitely without In the case of faint stars very narrow changing the length. spectra only can be obtained. Their energy is so feeble that they are capable of decomposing the silver particles only if allowed to fall upon them for a long time. In the enlargement the energy of the sun is substituted for that of the star, and thus an indefinite number of silver particles may be decomposed." (Introduction, p. xix.) The original negative may, perhaps, be compared to a "relay" in electrical apparatus.

The preparation of the Draper Catalogue involved five different steps, which are thus stated on p. 74:

I. Measurement of the spectra on each plate, including the determination of their positions, intensities, and the classes to which they belong.

II. Identification of each spectrum with that of a star in the Durchmusterung or other catalogue.

III. Reduction of the measures of brightness to the scale of the Harvard Photometry.

IV. Catalogues of plates.

V. Preparation of the final catalogue, bringing forward the places of all the stars to 1900, including various methods of checking and correcting the results.

That a catalogue of spectra may be of service to astronomers, a sound system of classification is essential, and this, as far as possible, should have some reference to chemical or physical constitution. The notable classifications which were suggested by eye observations were those of Secchi, Vogel, and Lockyer, but it is not surprising to find that the greater detail shown on the photographic plates requires modifications of these in order that all the spectra may be included. A detailed but somewhat arbitrary classification has been adopted by Prof. Pickering, the chief merit of which is that it readily lends itself to translation into other systems. Varieties of Secchi's first type are indicated by the letters A, B, C, D, those of the second type by the letters E to L, of the third type by M, and of the fourth type by N; bright line stars are referred to as O, planetary nebulæ as P, and other spectra as Q. Of the varieties of the first type, A includes all the stars with spectra similar to Sirius, and B those with spectra of the Rigel type, in which, in addition to lines of hydrogen, there is a small number of strong lines of which the origins are at present unknown.

Results of special interest, such as the discovery of bright lines in the spectra of variable stars of long period, have already been referred to in NATURE, and we shall now confine ourselves to the more general results. As some of the most interesting spectra belong to stars of small magnitude, it is necessary to be very guarded in making generalizations. Still, the fact that Prof. Pickering's researches have extended in some cases to stars of the ninth and tenth magnitude perhaps justifies the assumption that all types of spectra are now included. We cannot do better than let Prof. Pickering speak for himself.

"The general conclusion derived from the study of these spectra, is the marked similarity in constitution of the different stars. A large part of them-those of the first type-have a spectrum which at first sight seems to be continuous, except that it is traversed by broad dark bands due to hydrogen. Closer inspection shows that the K line is also present as a fine dark line. If the dispersion is large and the definition good, many more dark lines are visible, as stated above. These lines may be divided into two classes-first, those which predominate in many stars in the Milky Way, especially in the constellation of Orion; and, second, those present in the solar spectrum. Nearly all the brighter stars may be arranged in a series, beginning with those in Orion, in which the auxiliary lines are nearly as intense as those due to hydrogen. Other stars may be found, in which these lines successively become fainter and fainter, until they have nearly disappeared. The more marked solar lines then appear, become stronger and stronger, and the hydrogen lines fainter, until they gradually merge into a spectrum identical with that of the sun. At least, several hundred lines appear to be identical, and no differences can be detected. Continuing the sequence, the spectra pass gradually into those of the third type. Certain bands become more

marked, and the spectra of the third type may be divided into four clas-es. In the fourth of these classes the hydrogen lines are bright instead of dark. This spectrum seems to be characteristic of the variable stars of long period when near their maximum. As stated above, it has led to the detection of several new variable stars, and has been confirmed in many of the known variables. Slight peculiarities are noticed in the spectra of many stars, so that they cannot be arranged in an exact sequence; but these deviations are not sufficient to affect the general law. The number of stars not included in the above classification is very small. A few stars like y Cassiopeia, B Lyræ, and Centauri resemble the stars of the Orion type, but some of the lines are bright instead of dark. Stars of the fourth type, whose spectra appear to be identical with that of carbon, are not included in the above classification. Other stars, whose spectra consist mainly of bright lines, like those of the planetary nebulæ, may be included with them in a fifth class. It also appears that the position of the lines in both cases is probably identical with that of corresponding lines in stars of the Orion type." (Introduction, p. xvii.)

It would be difficult to find fault with the masterly way in which Prof. Pickering and his assistants have done their work. Our chief source of complaint, which no doubt arises more from impatience than anything else, is the lack of detail with regard to the spectra themselves. For investigations to which such a work as the Draper Catalogue should naturally lead, a mere estimation of the type of spectrum serves for little more than a determination of the relative numbers and distribution of the spectra of the various types. For the present, however, this is practically all that Prof. Pickering tells us. We are left quite in the dark, for instance, as to what is actually seen in the photographs of the spectra of stars of Secchi's fourth type, although we are informed that the photographic spectra are as characteristic as the visual. It would be interesting too, to know the differences in the sub-divisions of Secchi's third type.

All stars north of 20° of the fourth magnitude and brighter have been photographed on a large scale with the 11-inch refractor, and a discussion of these will occupy a subsequent volume of the "Annals.' This will be awaited with interest by all who are engaged in researches in astronomical physics.

We are delighted to find that the work of the Henry Draper Memorial is to be extended beyond the mere routine of photographing stellar spectra. "A broader field has been assigned to the Henry Draper Memorial by Mrs. Draper than was at first proposed. Instead of confining its work to the study of the spectra of the stars, their physical properties in general will be investigated. The liberal support given to it should give yet more striking results in the future than have hitherto been attained." (Introduction, p. xxiv.)

Laboratory work has already been commenced, and to aid the study of spectra in the electric arc, a 10-h. p. dynamo has been generously presented by the Edison Electric Co.

In the final chapter the Draper Catalogue is discussed with reference to the visual observations of Vogel and Konkoly. A similar comparison has already been given in NATURE, vol. xliv. p. 133, by Mr. Espin, and we need not further refer to it. We regret to find, however, that a discussion of the photographic spectra in relation to the new classification suggested by Mr. Lockyer has not been included.

It will be a source of gratification to Mr. Lockyer to find that his suggestion that stars of the Wolf-Rayet type are the first results of nebulous condensations is fully confirmed by Prof. Pickering's work. Their spectra greatly resemble those of the planetary nebula, the chief difference being that the characteristic nebula line near wave-length 500 is absent. This, Mr. Lockyer explains, is due to increased temperature, and this view is strengthened by the fact that the line was seen only during the later stages of the visibility of Nova Cygni. Nebule and bright line stars form Group I. of his classification.

So far, this is the chief point where the Draper Catalogue throws any additional light on Mr. Lockyer's views, and further discussion must be reserved until more details of the spectra are published.

66

The distribution of spectra" forms the subject of chapter vii., and we gather that the stars down to magnitude 6 25 are distributed as follows among the different classes of spectra :— Class A Class K 0.18 B M 0'013 "Peculiar " 0'007

0.61

0'02

F

0'12

0:05

According to Secchi's classification, placing Classes A, B, and F in the first type, G and K in the second, and M in the third, we have of the first type o°75, of the second o‘23, of the third oor, peculiar o'or" (p. 151).

To study the distribution in space, the sky was divided into 48 zones, and the results are thus summarised on p. 152. "It appears that the number of stars of the second and third type is nearly the same in the Milky Way as in other parts of the sky. Considering, therefore, only the stars whose spectra resemble that of our sun, we should find them nearly equally distributed in the sky. The stars of Class A, on the other hand, are twice as numerous in Region M (through which the Milky Way passes) as in Region N (an equal area away from the Milky Way), and in the case of Class B this ratio exceeds four. The Milky Way is therefore due to an aggregation of stars of the first type, a class to which our sun seems to bear no resemblance as regards its spectrum. Spectra of Class B seem to conform still more closely to the region of the Milky Way, although probably they are not sufficiently numerous to materially affect its light. The Milky Way must therefore be described as a distinct cluster of stars to which, from its composition or age, the sun does not seem to belong.'

The statement that the sun bears no resemblance to stars like those which chiefly constitute the Milky Way is not quite so precise as it might be. The lines in the spectra, so far as we know them, indicate the same substances in each, and the tendency of evidence is to show that the sun is a type of what the stars of the Milky Way will become.

Not the least interesting part of the researches connected with the formation of the Draper Catalogue is that dealing with the determination of photographic magnitudes. Elaborate investigations have been carried out by Prof. Pickering with his usual skill and care, and we hope to refer to them in some detail on another occasion.

No satisfactory method of applying the slitless spectroscope to the determination of velocities in the line of sight, except in the special case of a spectroscopic binary, has yet been devised, and this branch of research must therefore be carried out in the usual way. A. FOWLER.

UNIVERSITY AND EDUCATIONAL
INTELLIGENCE.

OXFORD. We regret to notice that the Savilian Professor of Geometry (J. J. Sylvester, Hon. D. C. L.), has had to apply for leave of absence and dispensation from the performance of statutory duties on account of ill-health. Mr. J. Griffiths, Fellow and Tutor of Jesus College, will lecture on the "Recent Geometry of the Circle and Triangle" for the Professor.

At a meeting of the Hebdomadal Council, Rev. W. Inge, Provost of Worcester College, and Rev. W. W. Jackson, Rector of Exeter College, were elected to be members of the Delegacy for the Training of Teachers under the provisions of the Statute approved by Convocation, November 24, 1891; and in a Congregation holden February 23, Joseph Wells, Fellow of Wadham College, and George R. Scott, Fellow of Merton College, were likewise elected members of the same Delegacy. In a Convocation holden on March 1, Mr. Henry Balfour, Trinity College, was appointed Curator of the Pitt-Rivers Museum, to hold office until December 31, 1898, and during that period to enjoy the same status in regard to the University Museum as the Professors teaching in the Museum, and to receive a stipend of 200 a year from January 1, 1892. The Curators of the University Chest were authorized to expend a sum not exceeding £150 a year from January 1, 1892, for seven years, on assistance and current expenses in the PittRivers Museum.

CAMBRIDGE.-Mrs. Phillipps offers to the University a sum of £2000 to found an "Arnold Gerstenberg Scholarship" in memory of her brother. The Scholarship is to be held by men or women who have passed the examination for the Natural Sciences Tripos, and intend to pursue the study of mental and moral philosophy.

A grant of £40 has been made to H. Kynaston, B. A. of King's, from the Worts Fund, to enable him to investigate the geology of the Eastern Alps in the ensuing summer.

Prof. Foster is appointed an Elector to the Downing Professorship of Medicine, to the Professorship of Zoology, and to

the Professorship of Botany; Prof. Dewar an Elector to the Professorship of Chemistry; Prof. Liveing an Elector to the Jacksonian Professorship; Prof. G. H. Darwin an Elector to the Cavendish Professorship of Physics; Prof. Sir G. G. Stokes an Elector to the Professorship of Mineralogy; Dr. J. Hopkin son an Elector to the Professorship of Mechanism and Applied Mechanics; Prof. Ray Lankester an Elector to the Professorship of Zoology; Mr. W. H. Hudleston to the Woodwardian Professorship of Geology; and Dr. Gaskell an Elector to the Professorship of Physiology.

At the Congregation on February 25, graces for the establishment of two lectureships in Agricultural Science, one of which should be held by a Director of Agricultural Studies, were rejected by 103 votes to 91. A grace for the appointment of a Syndicate to consider the question of degrees in science was rejected by 154 votes to 105. The latter was opposed by a number of the teachers in natural science, as tending to place their students in a position of isolation, and perhaps of inferiority, as compared with others.

The Rev. W. M. Campion, D.D., Fourth Wrangler in the Mathematical Tripos of 1849, and formerly an Examiner for the Mathematical and Moral Sciences Tripos, was on February 23 unanimously elected President of Queen's College, in succession to the late Dr. G. Phillips.

SOCIETIES AND ACADEMIES.
LONDON.

Royal Society, February 25.-"Note on the New Star in Auriga." By J. Norman Lockyer, F. R.S.

Since my note of February 11, observations of the new star have only been possible at Kensington on seven eveningsnamely, February 11, 12, 13, 16, 22, 23, and 24. The 13th and 22nd were the only two very fine nights.

The star now appears to be fading. In the photograph of the region taken on February 3, the Nova appeared to be brighter than x Auriga (magnitude 5'0), but in that taken on February 23 it is not brighter than the companion to this star, which is fainter than sixth magnitude. No marked diminution in brightness was noticed before February 22.

The colour has not appreciably changed since the star was first observed.

Photographs of the spectrum were attempted on all the dates named. Those of February 11, 12, 16, and 23, however, were insufficiently exposed, but they show that the dark lines were still more refrangible than the accompanying bright ones, and that the same lines were present as in the previous photographs. A plate was exposed for 2 hours 35 minutes on February 24, but no impression was obtained. The photograph taken on February 13 is identical with those referred to in the notes which I have already communicated to the Society. In the three photographs of February 22, there appears to be a slight diminution in the intensity of the H and K lines, but otherwise there is no decided change.

There is no evidence of revolution during the twenty days of observation. In all the photographs the dark lines are more refrangible than the bright ones, and the relative velocity deduced from those of February 3, 7, 13, and 22 appears to be about 600 miles per second. As this only represents the velocity in the line of sight, we are still ignorant of the real velocities of the two bodies. The constant relative velocity indicated by the displacement of the bright and dark lines may be regarded as confirming the supposition that two meteor-swarms or comets have collided, the velocities being so great, and the masses so small, that neither was captured by the other.

The relative velocity of 600 miles per second seems at first sight to be abnormally great, but if we regard each of the component swarms as moving at the rate of 300 miles per second, the velocities are quite comparable with those of other bodies in space. The star 1830 Groombridge, for example, moves at the rate of 200 miles per second across the line of sight, and its real velocity may be much greater.

Eye observations have been made on every available occasion. The chief variation from those previously reported is the general fading of the continuous spectrum, and the consequent unmasking of the lines between and D. Micrometric measures of four new lines in this region were made by Mr. Fowler on February 23 and 24. These, with the other lines observed at Kensington in the region F to C, are shown in the table which follows. The corresponding lines observed in the spectra of new stars which have previously appeared, and those in the spectra of some of the bright-line stars, are added for comparison.

The complete spectrum, including the photographic region, is shown in a diagram (which was exhibited). This, and the light curve of the spectrum from F to C, were drawn by Mr. Fowler and Mr. W. J. Lockyer on February 22, and confirmed by Mr. Fowler on February 23. The 3-foot reflector and McClean spectroscope were employed in each case.

The changes which are taking place in the Nova are exactly what would be expected according to my hypothesis that new stars are produced by the collisions of meteor-swarms. The

rapid fading of the star demonstrates that small bodies and not large ones are engaged, and this is further confirmed by the observed diminution in the brightness of the continuous spectrum relatively to the bright lines. If two condensed bodies were in collision, it is evident that the lines would fade first.

Chemical Society, February 4.-Prof. A. Crum Brown, F. R.S., President, in the chair. -The following papers were read-Pedetic motion in relation to colloidal solutions, by W. Ramsay. The pedetic or Brownian motion of small particles depends (1) on the size of the particles, (2) on their density, and (3) on the nature of the medium in which they are sus

pended. If an electrolyte be added to a liquid containing such particles in a state of pedetic motion, the movement is soon arrested, owing to the particles touching one another, and cohering to form clots or clusters. If no electrolyte be present, the particles do not tend to touch each other. From microscopic observations, it is calculated that a particle with a mass of 28 x 10 grams moves through, approximately, its own diameter, 14 x 10 c.m., in a second. Such a particle has one hundred billion times the estimated mass of a water molecule; hence, if its pedetic motion be produced by bombardment from water molecules, these must exist in complex groups of considerable mass and some stability. The fact that pedesis is stopped by the addition of an electrolyte would appear to indicate that the water complices are disintegrated in the presence of ions. The effect of pedetic motion in a liquid is to cause hydrostatic pressure; such hydrostatic pressure would be less on a membrane capable of penetration by the molecular aggregates or particles than on one not so permeable. It is not unlikely that these particles obey gaseous laws in regard to pressure on the sides of the containing vessel, as microscopic observations show that the relative velocity of the particles depends on their mass and density. L. Meyer has pointed out the great discrepancies existing between measurements of the osmotic pressures of solutions and the pressures calculated on the assumption that the dissolved substances obey gaseous laws. These discrepancies may be best explained by considering that combination of the dissolved substance with the membrane walls takes place, and that, subsequently, dissociation of the compound occurs at the other side of the cell wall, as in the case of hydrogen penetrating a palladium diaphragm. The author is disposed to conclude that solution is merely subdivision and admixture, accompanied by pedetic motion, that the true osmotic pressure has never been measured, and that a continuous passage can be traced between visible particles in suspension and matter in solution. The acid action of drawing-paper of different makes, by W. N. Hartley. An examination of numerous samples of the best drawing-papers shows that they all contain free sulphuric acid. Water in which the paper has been steeped yields a precipitate of barium sulphate, and solutions of helianthin and azolitmin painted on to the paper give the acid reaction. The interactions occurring in flames: a correspondence between Sir G. G. Stokes and H. E. Armstrong. Sir G. Stokes considers that the facility with which steam is decomposed by glowing carbon favours the view that, at a high temperature, oxygen co ubines with carbon in preference to hydrogen. He considers it necessary to distinguish carefully between the changes which take place in the partial combustion of a molecule and those which are produced in neighbouring molecules as a result of the heat liberated. This latter change

may be termed a thermo-chemical one, in contradistinction to a pure chemical change. In the blue base of a candle flame, where oxygen is plentiful, pure chemical change may occur. The blue part envelops for a little way the highly luminous shell in which glowing carbon is present. This carbon may owe its origin to a thermo-chemical change, the heat being derived from the pure chemical change occurring just outside it. The hydrocarbon spectrum may be due to a gas formed by a pure chemical change; this gas is generally supposed to be acetylene, but Sir G. Stokes considers that it is more probably methane. This unknown gas is a hydrocarbon, which, when burnt in the pure state, would show but feebly, if at all, the hydrocarbon spectrum. For, in order that it should show its spectrum, its molecule must be in a state of violent agitation; this might be expected to be the case if it had just been formed as the result of partial decomposition, but would not be so merely because it was going to be destroyed by union with oxygen. Dr. Armstrong, while admitting that the facts do not justify the assertion that oxygen combines with hydrogen in preference to carbon when a hydrocarbon is burnt with insufficient oxygen, is unprepared to adopt the view, advocated by Sir G. Stokes and Prof. Smithells, that the carbon is the more combustible, and thinks that the actual condition of affairs is far less simple than is expressed in the statement of either of these views. There seems to be very little opportunity in flames for simple heat changes to occur, the molecules of different kinds being so mixed up together. Thus opportunity is given for interactions to occur, the end result of which is the same as that of a simple heat change of the chief substance concerned; merely because a change occurring at one moment is reversed the next, and so escapes notice. In this way, con

tiguous molecules may play the part of surfaces, and that there can be little doubt that such actions are of primary importance may be inferred from the well-known fact that the extent to which the dissociation of water vapour takes place depends on the character of the surface in contact with which it is heated, and not solely on the temperature. In fine, it seems permis. sible to doubt whether, under the conditions present in flames, carbon is ever separated by simple heat changes. It will certainly be unwise at present to infer that the oxidation of the hydrocarbons, or the separation of carbon and also of hydrogen from them, takes place entirely in any one way. -Properties of alcoholic and other solutions of mercuric and other chlorides, by S. Skinner. The author has determined the variation in the boiling-point of alcohol produced by dissolving it in mercuric, lithium, magnesium, and calcium chlorides, as well as the variation in the boiling point of a solution of hydrogen chloride of constant boiling-point produced by mercuric chloride. He has also studied the distribution of mercuric chloride between the two solvents, water and ether. The results indicate that mercuric chloride affords a case in which the measure of the property is a simple function of the quantity of salt present, whereas in the case of the other chlorides, the measure of the property involves some higher power.-The isomeric a-bromocinnamic acids, by S. Ruhemann. An account is given of experiments on the action of ammonia and phenylhydrazine on the a bromccinnamic acids.

Entomological Society, February 10.-Mr. Frederick DuCane Godman, F.R.S., President, in the chair.-The President nominated Lord Walsingham, F. R. S., Captain Henry John Elwes, and Dr. D. Sharp, F.R.S., Vice-Presidents for the session 1892-93.-Mr E. Meyrick exhibited a number of specimens of Euproctis fulviceps, Walk., taken by Mr. Barnard, showing the extraordinary variation of this Tasmanian species, all the males of which had been "sembled" by one female. The males were represented by various forms ranging from black to white, which had all been described as distinct species. Dr. Sharp, Mr. Hampson, Mr. McLachlan, Colonel Swinhoe, Mr. Elwes, Mr. Poulton, and Mr. Jacoby took part in the discussion which ensued.-Dr. Sharp exhibited samples of pins which he had tried for preventing verdigris, and stated that silver wire was the best material to use, as insects on silver, pins remained intact, whilst those on gilt pins were destroyed by verdigris.Mr. G. T. Porritt exhibited a series of specimens representing Huddersfield forms of Polia chi, including nearly melanic specimens, found there during the last two seasons. He said these forms had not hitherto been observed elsewhere.-Mr. Tutt exhibited a series of Hadena pisi, comprising specimens very grey in tint, others of an almost unicolorous red with but faint markings, and others well marked with ochreous transverse lines; three distinct forms of Hadena dissimilis; red and grey forms of Panolis piniperda, and a dark form of Eupithecia fraxinata; also a specimen of Sciaphila penziana.—The Rev. Dr. Walker exhibited specimens of Arge titea, A. lachesis, A. psyche, A. thetis, and other species of the genus from the neighbourhood of Athens; also specimens of Argynnis phobe, taken in Grenada in May 1891.-Mr. W. Farren exhibited a series of specimens of Peronca variegana var. cirrana, and P. schalleriana var. latifasciana, from Scarborough; Eupecilia vectisana, from Wicken Fen; and Elachista subocellea, from Cambridge. Mr. G. A. J. Rothney sent for exhibition a number of species of ants collected in Australia, in May and June 1886, which had recently been named by Dr. Forel. The collection included: Iridomyrmex purpurens, Sm., I. rufoniger, Lowne, 1. gracilis, Lowne, I. itinerans, Lowne, Ectatomma metallicum, Sm., E. nudatum, E. mayri, Aphanogaster longiceps, Sm., Polyrhachis ammon, Fab., Myrmecia nigriventris, Mayr, and mgrocineta, Sm.; and a variety of Camponotus rubiginosus, Mayr, from Brisbane; also a few species from Honolulu ; and a species of Monomorium, which Dr. Forel had not yet determined.-Mr. C. O. Waterhouse read a paper entitled "Some Observations on the Mouth Organs of Diptera," which was illustrated by numerous diagrams.-Mr. E. Meyrick read a paper entitled "On the Classification of the Geometrina of the European Fauna." Mr. Hampson, Mr. Elwes, Mr. McLachlan, Colonel Swinhoe, Mr. Tutt, and Mr. Distant took part in the discussion which ensued.

Zoological Society, February 16.-Osbert Salvin, F.R.S., Vice-President, in the chair.-Mr. W. T. Blanford, F.R.S., exhibited two heads and a skin of the Yarkand Stag, lent for