struction were arranged for hospital assistants and others with reference to plague inoculation and bacteriological work.

MR. C. CARUS-WILSON has printed a paper, read by him before the Geological Society of London, on the pitting of flint surfaces. He directs attention to the frequently polygonal and rudely hexagonal character of the outer ends of the pits found on flints in a certain stage of decomposition, and to the considerable amount of water that may be absorbed by the external layers of such flints. But he shows much uncertainty of view as to the mode of origin of the pits; the suggestion made in the text that their polygonal outlines are connected with the crystalline form of the absorbed water as it froze seems, to say the least, fantastic. In a footnote, however, the author compares these outlines with the shrinkage-cracks of such rocks as basalt, and regards the ice merely as the agent that split off the lost portions of the flint. Would it not be simpler to regard the rudely polygonal outlines as resulting from the intersection of successively formed and adjacent cup-like surfaces of fracture?

We have received the report of the chief inspector of mines in Mysore for the year 1907-8, which opens with the statement that there was a large diminution in the number of applications for mining licenses as compared with the previous year; the statistics of licenses granted show, on the other hand, an increase from 101 in 1906 to 242 in 1907. The gold production showed a decrease of 5.84 per cent. as against a decrease of 8.67 per cent. in 1906, the comparison in each case being with the previous year; it amounted to a value of 2,041,129. in 1907, and the total value of bullion produced from the commencement of mining operations in 1882 to the end of June, 1908, was 28,598,1551. Air blasts seem still to be frequent, but there was a decrease in the number of accidents. Statistics are given of the production of manganese and chrome, 82,835 tons and 11,197 tons respectively, but as regards other minerals it is reported

that the statistics have been handed over to the curator of the Geological Museum for report as to whether it is possible to extract any useful information from them.

THE Proceedings of the Royal Society of Edinburgh (vol. xxix., p. 602) contains a paper, by Mr. E. M. Wedderburn, on the deep-water oscillations recently described by Prof. Pettersson (NATURE, August 12, p. 197). Working on a suggestion made by Sir John Murray, Mr. Wedderburn

adduces evidence to show that the oscillations observed in the Skagerak are analogous to those which have been observed by the Scottish Lake Survey, and that they really show the presence, not of a long-period tide, but of a temperature seiche, having its node at the mouth of the Skagerak and its loop at the point of observation.

AN important paper on evaporation in Egypt and the Sudan, by Mr. B. F. E. Keeling, is published by the Survey Department of Egypt. The author first deals with the results of comparisons of various types of evaporimeters used in Egypt at different times. Those now in use are mostly of the Piche and Wild patterns, exposed in doublelouvred screens; their readings are apparently comparable in different climates, if similarly exposed, where the mean wind velocities are not widely different. A table is given showing the mean daily evaporation at stations in the Nile Valley; in Egypt and the North Sudan it is greater in the summer, while in the rainy areas it is at a maximum in the dry winter season, as is to be expected. One section of the report deals with the evaporation from open expanses of water. In the neighbourhood of Cairo the mean amount was 4.2 mm. per day (winter 3 mm., summer 5.3 mm.); on Lake Victoria it is estimated at 3 mm. per day. In the last section some remarks are made on the relation of evaporation to other meteorological factors; the mean daily curve of evaporation at Helwan closely follows the curve of saturation deficit.

IN the September issue of Man Prof. Flinders Petrie describes a find of string nets of the seventeenth Egyptian dynasty which are practically unique. They were found associated with an untouched burial near Thebes. This is, perhaps, the most varied and rich collection of funeral remains which has ever been brought from Egypt. It will be preserved as an entire group in the Royal Scottish Museum, Edinburgh. The corpse was enclosed in a single coffin painted with wings in blue and gold. On the neck was a splendid golden collar; on each arm a gold armlet; round the waist an electrum girdle, copied from a Nubian pattern, made of seeds and leather. The whole collection of jewellery weighs half a pound avoirdupois-the largest group of gold-work which has ever left Egypt. The string nets associated with these remains, of which Prof. Petrie gives photographs, illustrate the remarkable skill in stringworking attained by the Egyptians of that era. He also announces the discovery, at Memphis, of the great palace of King Apries (about 580 B.C.). Scale armour, bronzes, a remarkable silver plaque with a gold figure of Hathor, and a great carved portal, now in ruins, are part of the discoveries at this site.

IN the September issue of Man Dr. C. G. Seligmann describes what is known as the Bandar cult among the

question of changes on the east-coast region of England during the historical period, undertaken by the research department of the Royal Geographical Society. Mr. Sheppard, after pointing out that the coast line between Bridlington and Spurn Point is of special interest because, while on the one hand enormous tracts of land have disappeared within historic times, on the other large areas have been formed, embanked, and cultivated, divides his district into five sections, the Holderness coast from Bridlington to Kilnsea, Spurn Point, the North Humber shore, the South Humber shore, and the Humber itself. Each district is treated from the point of view of geological

Bandar being the title applied to the canonised spirits of eminent persons to whom, soon after their death, offerings are presented in order to induce them to protect the worshipper from evil and to grant him good fortune. One of the most important of these spirits is Kosgama Bandar, who takes his name from the village in which he lived in the eighteenth century or earlier. He seems to have rebelled against the King of Kandy, by whom he was captured and executed. He and similar spirits exercise authority under the control of Skanda, one of the four guardian deities of Ceylon. Dr. Seligmann prints, with a translation, a curious invocation addressed to this spirit.

FASCICULES I and 2 of the Bulletin des Séances de la Société français de Physique for 1909 contain thirteen memoirs, several of which have already been noticed in these columns. Amongst those not previously dealt with may be mentioned that by M. G. Delvalez, on the Hall effect in liquids. According to the electronic theory of conduction of electricity, this effect should be extremely small, while experiment appeared to show that it was a million times greater than the theoretical value. M. Delvalez has succeeded in showing that these observed effects were due to the convection currents in the liquid, set up because it is a mobile conductor carrying current through a magnetic field. The motion generates an electromotive force, which has been measured as the Hall effect. By using an alternating electromotive force to produce his main current, and arranging to balance the Hall electromotive force against the fall of potential down an induction free resistance traversed by the main current, he has shown that the effect is very small, certainly less than one three-thousandth of the value previously observed.

THE use of platinum felt, as suggested by Monroe in 1888, in place of asbestos as a filtering medium is recommended by Mr. W. O. Snelling in a paper in the Journal of the American Chemical Society (vol. xxxi., pp. 456–461). In addition to its insolubility in almost all the ordinary chemical agents, it has the advantage of extraordinary porosity, combined with the power of retaining completely and easily such finely divided precipitates as barium sulphate and calcium oxalate; a series of tests showed that the filtration was six times more rapid than with an asbestos filter containing one-third the quantity of asbestos. The precipitate can be dissolved off, and the felt used again and again; moreover, a damaged filter can readily be patched by the adding of chloroplatinic acid and igniting. The use of the "Monroe crucible for atomic-weight determinations is especially advocated. Another issue of the same journal contains a paper by Mr. J. T. Stoddard on rapid electro-analysis with stationary electrodes (ibid., pp. 385-390), in which it is claimed that by using a kathode of gauze or of mercury, a stationary anode, and a heavy current, complete decomposition of the metal can be effected as rapidly as with a rotating electrode; under these conditions the liberation of gas, and the convection currents consequent on the heating of the liquid, appear to provide sufficiently for the agitation of the fluid without recourse to mechanical methods.

THE Philippine Journal of Science for March contains a third paper by Raymond F. Bacon on the Philippine terpenes and essential oils, and a paper by Mr. H. D. Gibbs on the oxidation of phenol. The latter author has taken advantage of the tropical sunshine to study the red coloration which is developed by phenol when exposed to air and light, and has carried out the investigation with remarkable care and thoroughness. He shows that the phenol becomes coloured in presence of oxygen, but not of hydrogen, nitrogen, and carbon dioxide. The action is caused by oxidation, quinol, quinone, catechol, and carbon dioxide being produced; the principal coloured compounds are probably quinone condensation products, the red colour being attributed to phenoquinone. The oxidation is not appreciable in the dark at room-temperatures, but becomes measurable at 100°, and fairly rapid at the boiling point of phenol. In sunlight the rate of coloration is rapid, and increases with the temperature; it is affected by the ultraviolet absorption of the glass, by atmospheric conditions, and by the altitude of the sun. Ozone, is very reactive; it gives the same products as oxygen, and in addition

glyoxylic acid has been detected. Anisol, the methyl ether of phenol, gives no coloration either by the action of ozone or of oxygen and sunlight.

MESSRS. E. B. ATKINSON AND Co., of Hull, forward us an improved pattern of Soxhlet's apparatus for the extrac tion of oils and fats. The new form is fitted with a glass stop-cock on the syphon tube. By regulating the overflow, the thimble can be kept full of the solvent during the extraction, instead of being alternately filled and emptied. Also, by closing the stop-cock at the end of an operation, the solvent can be retained in the upper part of the apparatus; this allows the flask containing the extracted fat to be almost freed from the solvent, so that it can be placed straightway in the drying-oven. A bulb on the upper part of the side-tube facilitates the passage of the vaporised solvent if liquid should collect there. The new pattern thus appears to have distinct advantages over the older form.

THE use of the Walschaerts valve gear on American locomotives has been greatly extended since its introduction into the States a few years ago. The advantages of this gear render it very suitable for the large engines employed in America, and its success has led to experiments with others of a similar type. Several railways are now trying the Pilliod motion, a gear made by the Pilliod Company of Chicago, and described in the Engineer for September 3. In this gear, as in the Walschaerts, the motion is derived partly from a return crank on the main crank-pin and partly from the crosshead. The moving parts are the same for any class of engine, and weigh about 1000 lb. There is no load on the reversing lever, which can be unlatched and moved in any condition with the regulator either open or closed. The motion is expected to effect a considerable saving in fuel and in maintenance and repairs. The release is late; thus with cut-off at 25 per cent. the release is at 85 per cent.; the Walschaerts gear, with a similar cut-off, releases at about 65 per cent. of the stroke. Special adaptability for high speeds is claimed.

19h. Mercury at greatest elongation west. 31. 9h. 8m. Minimum of Algol (B Persei). OBSERVATIONS OF HALLEY'S COMET, 1909c.-Photographs showing Halley's comet were obtained at the Greenwich Observatory, with the 30-inch reflector, on September 9, two days before it was discovered by Prof. Wolf. Owing to the proximity of the moon the two exposures were limited to thirty minutes and twenty-five minutes respectively, and the very faint cometary images were not identified until after the receipt of the telegram announcing the discovery at Heidelberg. The positions determined gave corrections of +24s. and -4' to the ephemeris published in No. 4330 of the Astronomische Nachrichten.

In a supplement to No. 4356 of the Astronomische Nachrichten, where the above observations are recorded,

Photographs were also secured by Mr. Knox Shaw at the Helwan Observatory on September 13 and 15, and by Dr. H. D. Curtis, with the Crossley reflector at the Lick Observatory, on September 12, 13, and 14.

ANOTHER LARGE SUN-SPOT.-During last week another large sun-spot was to be seen on the solar disc. It was first observed, at South Kensington, on September 18 near to the limb and a few degrees south of the sun's equator. Developments took place until on Saturday last, when just past the central meridian, it consisted of one large nucleus and several smaller ones, and was visible to the naked eve. It is perhaps worthy of note that a magnetic storm, of sufficient magnitude to interfere seriously with the transmission of telegrams, took place on Saturday.

OBSERVATIONS OF MARS.-In a telegram to the Kiel Centralstelle (Circular No. 112), Prof. Lowell announces that the Martian antarctic canals are disappearing, and that the general pallor of the various features continues. He also states that the Solis Lacus is double.

Regarding the naked-eye appearance of the planet, Mr. J. H. Elgie recently directed attention to the apparent nearness of Mars as compared with the neighbouring stars of Pegasus. He suggests that this sense of nearness might be due to the propinquity of a wooded ridge over which the planet was rising, the Pegasus stars being well above the ridge, and therefore beyond this influence. At the same time, the brilliant irradiation of the planet seems quite sufficient to account for a phenomenon which must appeal to anyone seeing the planet on a clear evening.

OBSERVATIONS OF SATURN.-A telegram from Prof. Lowell to the Kiel Centralstelle, published in Circular No. 113, announces that a dark medial streak has been observed on Saturn's equator, and that there is an appearance of lacings similar to those seen on Jupiter. Further, an intense white spot, in saturnian latitude 50° S., was detected by Mr. Slipher and transitted at 14h. 5m. (Washington time) on September 23.

THE FUTURE OF ASTRONOMY.-In an address delivered at the Case School of Applied Science, Cleveland (U.S.A.), in May, Prof. E. C. Pickering took as his subject the future development of astronomy, paying special attention to the methods whereby the limited financial resources and personnel may be used with the greatest advantage to the science. After a review of the several past epochs of astronomy, and some rather amusing remarks as to how monetary gifts are made and used at present, he outlined the general scheme, to which he has previously referred on various occasions, and the principle of which underlies the splendid organisation of resources built up at the Harvard College Observatory. The central feature of the scheme is one large, and perforce international, observatory employing, say, 200 or 300 assistants, and maintaining three stations. Of the latter, one would be in latitude about 30° N., and another the same distance south; western America is suggested as a suitable locale for the former, South Africa for the latter, and each would be selected wholly for its climatic conditions, which premises fairly great altitudes and desert regions. Each observing station would have instruments of the largest size, such as the 7-foot reflector previously suggested for South Africa, and would do practically no reductions or measuring. These would be carried out at the third station, situated where living and labour are cheap, where the photographs, &c., would be stored. Such an organisation would exist for the benefit of all serious astronomers; anyone wishing to engage on any piece of work would simply requisition the raw material, e.g. sets of special photographs, from the central bureau. If not in stock, the required photographs would be secured at the earliest convenient opportunity. By thus centralising and organising astronomical resources, Prof. Pickering claims that the science would benefit immensely, because the waste at present resulting from overlapping, or from being forced to use inadequate raw material, would thereby be eliminated (Popular Science Monthly, vol. lxxv., No. 2).

THE INSTITUTE OF METALS.

THE publication of the first volume of the Journal of the Institute of Metals marks the completion of a full year's work. The institute has been formed to advance and disseminate knowledge in connection with the manufacture and properties of the non-ferrous metals and alloys. The members are fortunate in having for first president Sir Wm. White, who delivered an excellent address, in the course of which he dealt in a very able manner as well with the delicate subject of trade secrets as with the important one of the relationships between manufacturers and users of metals, although his oftreiterated special pleading for National Physical Laboratory during the meetings must have been rather wearying to the other important workers represented.

the

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The paper by Mr. J. T. Milton, chief engineer of Lloyd's, on some points of interest concerning copper and copper alloys, is mainly about troubles experienced by users, and is valuable for members of all types; but the statement on p. 68 that the temperature of pouring the white metal into bearings is left to the ordinary workman is not the case in at least one of the great Sheffield-Clyde firms, as for many years this has been done with the aid of a suitable pyrometer, and probably is so still. The paper drew a very long and good discussion, in which Prof. Gowland's remarks that ancient bronzes were very impure, so that their hardness could not be due to exceptional purity, and that by careful hammering modern bronzes can be made as hard as ancient, were of interest to those who are often being met by the statement that the method of hardening bronze tools is a lost art.

The mechanism of annealing in the case of certain copper alloys, by Messrs. G. D. Bengough and O. F. Hudson, is of a very theoretical nature as a whole, but gives several practical hints on the treatment of brass. Mr. J. T. W. Echevarri's paper, on aluminium and some of its uses, is most interesting, although his reasons for its efficacy in preventing blow-holes in steel (p. 130)—that it combines with the gases and produces an innocuous slagwould hardly be accepted. In the discussion the president remarked that not only had aluminium proved unsatisfactory for shipbuilding because of serious corrosion (p. 156), but that, though suitable aluminium alloys might yet be obtained, they had to be discovered. Notes on phosphor-bronze, by Mr. A. Philip, is thoroughly practical, and contains several tables of tests with corresponding analyses, with a full discussion as to the most suitable compositions and tests for different purposes.

In metallographic investigations of alloys Mr. W. Rosenhain gives a good critical summary of methods, but, unfortunately, attempts to bolster up the discredited differential method of taking cooling curves. On p. 213 he recommends that "the slowest possible rate of cooling should be adopted in cooling-curve experiments "; but long experience teaches that the rate of cooling must be chosen according to the nature of the alloy and the objects of the investigation. In Dr. Desch's paper, on inter-metallic compounds, surely the complicated "broken solidus curve MBNPQRESTUĞ" for an institute of metals might have been better chosen from a real example than an imaginary one, so that such members as waded through it all would have a reward of facts as well as principles. Dr. Shepherd in the discussion endeavoured to explain to the members what the present writer has tried to impress on several investigators, namely, that though a pyrometer be capable of great accuracy, it does not follow that the phenomena are observed to the same degree of accuracy, and also that though the phase rule is a guide, it must be remembered that it was deduced for ideal conditions, and takes no account of the time factor or of the rate of diffusion or viscosity. Dr. Shepherd favours the use of heating curves, but his remark that "in the case of transformations in the solid phase he had found no satisfactory results with cooling curves must sound strange to investigators on steel-the pioneers in this type of work -the well-known Art, Ar2, Ar3 being all points on cooling curves. For demonstration purposes cooling curves are generally taken because more convenient, but for a comnlete investigation both heating and cooling curves must be studied. Had this not been done, the important effect

appreciation. He can pursue his studies unaffected by any considerations save those of adding to the sum of human knowledge and of bringing a necessary task appreciably nearer completion. In descriptive study it is the work rather than the personality of the worker that tells. Yet the work is not without human interest, because systematic writings rarely fail to reflect the character of the writers. The intimate knowledge of descriptive treatises, which floristic or monographic study entails, usually leads to mental estimates of the actual authors. The evidence on which these estimates depend is unwittingly given and unconsciously appreciated. But its value is not thereby diminished, and estimates so formed may prove useful checks on contemporary judgments.

The descriptive worker as a rule makes his work "the primary business of his life, which he studies and practises as if nothing else in the world mattered." But he does not hold aloof from those engaged in other lines of botanical activity. His evidence is mainly obtained from organography and organogeny; but, just because his results are for the use of others, the descriptive botanist has to keep abreast of all that is done in every branch of his science. New weapons are constantly being forged, and not in morphological workshops only; with these and their uses the descriptive worker must be familiar, for the need to employ them may arise at any moment. If he does not always abandon old friends for new, this is not because the systematist is unaware of their existence, or unprepared to apply new methods. The descriptive worker employs his tools as a craftsman; like other craftsmen, he finds that tools do not always fulfil the hopes of their designers. In descriptive work, too, as elsewhere, a steam hammer is not required to break every nut; the staff and sling may be arms as effective as those of the hoplite. There are occasions when the descriptive writer does appear to hold aloof by declining to accept proffered evidence. But his motive is not arrogant; it is only altruistic. If he is to avoid the risk of causing those who depend on his results to reason in a circle, the descriptive writer must obtain these results, if not without extraneous aid, at least without help from those for whose immediate use they are provided.

Taxonomic study is pursued in an environment which differs from that surrounding descriptive work. The descriptive student can hardly see the wood for its trees. The taxonomic student works in more open country, and can look on the wood as a whole. He has, too, the benefit of companionship. The palæobotanist meets him, with all the lore of mine and quarry, as one ready to exchange counsel; other workers attend to give or gather information.

The community of interest which unites the systematic worker, chiefly concerned with existing plant-types, and the palæobotanist, primarily interested in types now extinct, is strengthened by the bond which identity of purpose supplies. But the two are differently circumstanced; the systematic worker is ordinarily better acquainted with the characters than with the relationships of his types; the palæobotanist usually knows more of the relationships of his types than he does, or ever may do, of their characters. The material of the palæobotanist rarely lets him rely on ordinary descriptive methods in defining his plants; he has to depend largely on anatomical evidence, which supplements and confirms, but hardly replaces, the data of organography. On the taxonomic side the palæobotanist is restricted to phylogenetic methods; here again he is handicapped, though less than on the descriptive side, by the fragmentary character of his specimens. The palæobotanist hardly does more than the phylogenist, hardly as much as the anatomist, towards advancing the object all have in common.

The same community of interest unites in their labours the organographic systematist and the morphologis: whose interests are phylogenetic. Here, however, though the task of the two be complementary, the mode of attack is so different as almost to mask their identity of purpose. The comparative morphologist studies the planes of cleavage indicated by salient differences in structure and development. The system he evolves is composed of the entities, sometimes more or less subjective, that combinations of characters suggest. The method in intention, and largely

in effect, passes from the general to the more particular, though the process is tempered by the fact that the characters used are derived from such types as exhibit them. The organographic systematist, after summing up the characters which mark individual types, aggregates these according to their kinds. Having estimated the features that characterise individual kinds, he aggregates these according to their families. Families are thereafter aggregated in higher groups, and these groups are subjected to further aggregation. The system thus evolved is composed of those entities, always in theory objective, that successive aggregations indicate, and the process is one of constantly widening generalisation.

The comparative morphologist, though glad when his results can be practically applied, follows truth for its own sake. His work is thus on a higher plane than that of the organographic systematist, whose aggregations are primarily utilitarian. But the work of the latter is not less valuable because its scientific character is incidental. Were our knowledge of plant-types exhaustive, a generally accepted artificial arrangement of these would be as useful to the applied botanist as a professedly natural one. But our knowledge is incomplete, and the accession and intercalation of new types renders any artificial, and most attempts at a natural, system sooner or later unworkable. The more closely an arrangement approximates to the natural system, the less can the intercalation of new forms affect its stability. The more stable a system is, the more easily will its details be remembered and the more useful will it prove in practical reference work. Here, therefore, for once, self-interest and love of truth go hand in hand.

Since the organographic systematist learns their characters from his groups, while the comparative morphologist defines groups by the characters he selects, their results, were knowledge complete, should be identical, and this identity should prove their accuracy. But knowledge is finite, and these results are not always uniform. The want of uniformity is, however, often exaggerated because the reasons are not always appreciated.

One cause is the difference in personal equation, which affects alike the worker who deals with things and him who considers attributes. It would be contrary to expectation were every phylogenist to assign the same value to each character, or every systematist to apply the same limitation to each type or group of types. The divergence of view on the part of two observers may show a small initial angle; it may nevertheless lead them to positions far apart. But while divergence of view is the most obvious explanation of the want of uniformity apparent in systematic results, it is the least effective cause. inherent tendency to differ manifests itself in contrary directions; in the long run individual variations are apt to cancel each other.

This

The nature of the work counts for more than the predisposition of the worker. The aggregations on organographic lines, which were the main guides to the composition of the higher groups until phylogenetic study was seriously undertaken, do not assist the comparative morphologist. The characters on which phylogenetic conclusions may be based increase in value in proportion to the width of their incidence, so that the greater their value for phylogenetic purposes the less do they aid the descriptive worker in discriminating between one plant-type and another. Often they are characters which for practical reasons the descriptive worker must avoid. Organography, then, may not give evidence as to characters whereof cognisance cannot be taken, while for another reason the comparative morphologist may not use characters derived from descriptive sources. The object of the phylogenist is to take his share in advancing our knowledge of taxonomy; to seek from the systematist the evidence on which his results are based would be to vitiate the reasoning of both. All that the phylogenist can ask the descriptive worker to do is to supply the units that require classification.

The comparative morphologist, relying mainly on anatomical and embryological evidence, at first had a hope that his method of study might enable him to supply his own units and thereby render further taxonomic work based on organography unnecessary. This hope remains unfulfilled, and the phylogenist, as a rule, limits his efforts