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THE papers in the Zeitschrift für wissenschaftliche Zoologie (vol. lxxx., part i.) include one by Mr. V. Widakowich on the structure and function of the so-called nidamental organs (that is to say, the glands which secrete the white and shell of the eggs) of the shark Scyllium canicula. In a second Mr. A. Reichensperger describes the anatomy of the living West Indian crinoid Pentacrinus decorus. A third, by Mr. O. C. Glaser, is devoted to certain features in the physiology of the American gastropod Fasciolaria tulipa, while in a fourth Messrs. Marshall and Dernehl commence a dissertation on the embryology and anatomy of the hymenopterous insect Polistes pallipes.
To the first part of the eightieth volume of the Zeitschrift für wissenschaftliche Zoologie Dr. O. Grosser communicates an interesting paper on the evidence that certain dermal structures or markings among vertebrates have a segmental origin. Among the features referred to are the transverse arrangement of the scaling on the under surface and sides of the body in lizards, and the transverse colourbands on the bodies of the banded mongoose (Crossarchus fasciatus), the tiger, and the zebras. In regard to the scaling of reptiles, the author admits that the transverse arrangement is very probably a secondary feature due to adaptation to the movements of the body, while he adds that the evidence for the segmental origin of the transverse stripes in mammals is purely of a negative nature, and requires something much more definite in its favour before it can be accepted. It may be added that if this segmental origin of colour stripes be accepted, it at once cuts away the ground from those who regard it as a special protective adaptation.
WE have received the first part of a work, to be completed in six parts, price sixpence each, entitled "I go a-walking through the Country Lanes." No author's name appears on the title-page, but the text is stated to be compiled from the Rev. C. Johns's "British Birds and their Haunts." Each part is to contain reproductions from photographs taken by Mr. Reid, of Wishaw, the incomparable excellence of which needs no commendation on our part. The aim of the book is "to outline a walk in the country, and to describe and picture the habits of the birds and the animals that are to be seen." The photographs in some instances might have been made to convey more information. On p. 13 we have, for instance, a charming picture of a flock of sheep coming out of a field, to which the legend changing pastures" is subscribed. It would surely have been just as easy to mention that these sheep, as shown by their white faces and long wool, are Leicesters, or some nearly kindred breed.
THE Selborne Society has issued an illustrated circular in which attention is directed to the objects coming within the purview of that body, and the privileges enjoyed by members. "Birds in the Field and Garden" is the title of an article in the October issue of Nature Notes, the official organ of the society, in which the nameless author, while admitting that a certain amount of damage is inflicted on fruit and other produce, maintains that, on the whole, the visits of birds are advantageous alike to the gardener, the fruit-grower, and the farmer. In connection with this subject, it may be mentioned that we are acquainted with certain gardens where, owing to the damage done to the buds by bullfinches and other members of the finch tribe, the whole of the gooseberry and currant bushes have been enclosed in wire netting with a mesh small enough to prevent the entrance of birds. The experiment has been carried on for two seasons with the
most satisfactory results, and there has been no necessity to take any special steps to free the bushes from insects Here, then, is a problem for those who urge that birds are essential to the gardener.
IN Biologisches Centralblatt for October 1 Mr. W. M. Wheeler, of the American Museum of Natural History, and Father E. Wasmann discuss the discovery of "temporary social parasitism" among ants, and the inductions to be drawn therefrom as to the origin of "slavery among certain members of the group. Mr. Wheeler claims to have been the first to describe this temporary parasitism in a Bulletin of the U.S. National Museum issued in October, 1904; but the corollaries from this discovery and inferences in regard to the general origin of slavery among ants were not published by him until the middle of February of this year. In conclusion, the writer urges that none of the observations published by Father Wasmann during all the years he has been engaged in the study of ants arr sufficient to accredit him with the independent discovery of temporary social parasitism as a general and regular phenomenon among certain Formicida." In a reply to this article, Father Wasmann very candidly admits that Mr. Wheeler is fully entitled to the credit of this discovery, although he apparently does not accept certain other claims made by the American naturalist
"CAN fish hear?" is a question discussed by Dr. O. Körner in a special issue of the Beiträge sur Ohrenheilkunde, published to commemorate the seventieth birthday of Prof. A. Lucae. The question is provisionally answered in the negative, and for the following reasons. It seems that many fishes are able to perceive rapid, consecutive vibrations communicated to water, but that such vibrations are taken cognisance of by means of the so-called auditory organs is highly improbable. This is supported by the fact that single loud explosions in water were totally disregarded by fishes belonging to no less than five and twenty distinct species of fishes. Moreover, the circumstance that the presence of the senses of sight and touch is easily demonstrable in fishes renders it probable that the same would be the case with hearing if it existed. Finally, the fact that fishes, and apparently also such isolated forms in other groups as are deaf, alone among vertebrates possess no organs comparable to the Cortischian nerveterminations renders it probable that these organs are alone capable of transmitting auditory vibrations, the hypothesis that such vibrations may be received by the vestibular apparatus not being at present substantiated.
WE have received part ii. of an illustrated catalogue of the ethnographical collection of the Sarawak Museum (Journal No. 43, April, Straits Branch, Royal Asiatic Society), by Mr. R. Shelford. This section deals only with the objects worn for decorative purposes by the natives of Borneo. The question of the relationship between magic and personal ornamentation has not been lost sight of, but many inquiries have elicited little information of importance. Kalabit youths when visiting new districts wear a necklace of decorative seeds as charm against evil spirits, and Land-Dyak men Wear 3 necklet of beads and canines of leopard and bear for a similar purpose; the beads are frequently regarded as charms against specific diseases. The leglets of finely plaited fibre so commonly worn were at one time employed as currency; the Kayans say they feel quite naked if they do not wear these leglets. The catalogue is very well done, and is illustrated by adequate plates. If the whole museum is treated in this way the catalogue will provN » to be a very valuable record of the ethnography of Sarawak
THE Bulletin du Jardin impérial botanique de St. Petersbourg, vol. v., part iii., contains a description of new lichens from Central Russia and Siberia, by Mr. A. Elenkin, and an account of the vegetation on the chalk cliffs in the basin of the river Choper, by Mr. W. Dubjansky.
IN his report for 1904-5, the curator of the botanic station in Dominica states that spineless lime plants are in great demand, but that he is unable to furnish an adequate supply, as the fruits contain very few seeds; also, owing to the labour involved, the supply of budded orange stock is limited. Other plants in request are cacao, rubber -both Castilloa and Funtumia and ordinary limes. Judging from the manurial experiments with cacao, extending over three years, the application of phosphate and potash with dried blood may be expected to give substantial increases in yield, while mulching with grass has produced even better results.
THE Department of Agriculture for British East Africa has issued a leaflet on the cultivation and commercial
products of the cocoanut. The industry is one that requires some capital, as the plants only come into bearing in the sixth year, and meantime the cultivator is dependent upon the maize, ground-nuts, or any other crop that he may grow between the trees. The most lucrative product in East Africa is tembo, a liquor obtained from the cut end of the very young flowering spike. The Department of Forestry in the same colony has also inaugurated a series of leaflets, the first of which deals with timber trees, including a juniper, a Podocarpus, Pygeum africanum, and Allophylus abyssinicus.
consists of brown-coal briquettes. The same firm showed an eight horse-power locomotive with a benzene motor.
FROM the Rationalist Press Association there come cheap reprints of "The Fundamental Principles of the Positive Philosophy " and of Haeckel's "The Wonders of Life." The former book contains a translation of the two introductory chapters of Comte's "Philosophie Positive," that is, the account of Comte's main theses, of the law of the three states of knowledge and the nature of positive philosophy, together with the fulminations against introspective psychology which are now completely out of date. Haeckel's work is a supplement to the "Riddle of the Universe, and discusses life, death, morality, and many other things.
WE have received a pamphlet entitled "The Growth of Oak in High Forest," by Prof. W. R. Fisher, president of the Royal English Arboricultural Society, in which the author points out the desirability of having a model oak high forest as an adjunct to the forestry school at Oxford. In spite of the fact that oak forests and oak timber have played such an important part in the history of England, we have not at the present day a typical example of oak high wood, that is, an area where all stages from the seedling to the mature tree are represented. In the above pamphlet Prof. Fisher proposes to have a working section of the oak wood in Windsor Park set aside for this purpose. The area required, 1200 acres, could surely be spared for this important purpose, and the author clearly shows how the present crop could with time be replaced by a series of age classes representing all stages in the growth of the tree and the forest from the beginning to the end of the rotation. The financial returns would be vastly increased thereby, more than counterbalancing and justifying any small initial sacrifice. The scheme deserves every encouragement, and we trust will be looked upon with favour by those in authority.
ONE of the best concise accounts of the Liége Inter- | national Exhibition yet published is contributed by Mr. L. Ramakers to the October issue of the Engineering Magazine. Some excellent illustrations are given of the mechanical, mining, and metallurgical features. Several large engines for operation with blast-furnace waste gas were shown, notably a 1200 horse-power four-cycle doubleacting horizontal tandem engine for the direct driving of a rolling mill at the Cockerill works. Another gas engine shown by the same firm is a 500 horse-power four-cycle double-acting twin cylinder for operation with coke-oven waste gas. A gas-producer of novel type was exhibited by the Deutz Gas Engine Works, the fuel for which
FIG. 1. Photograph of the Sun showing the large group of sun-spots October 19, 12 o'clock noon.
miles across its greatest breadth. The smaller spot, seen in the N.W. quadrant, was of particular beauty, showing a very dark circular umbra surrounded by a symmetrical penumbra.
A second naked-eye" spot having a large black nucleus was seen near to the eastern limb of the sun on Monday last. This is the second occasion during the present year that the sun has presented the unusual phenomenon of two naked-eye spots visible on the disc at the same time.
FURTHER RESULTS OF THE FRENCH ECLIPSE EXPEDITIONS. --Yet another batch of the preliminary results obtained by French expeditions during the recent total eclipse of the sun is published in No. 15 of the Comptes rendus.
Prof. Janssen, who was in charge of the expedition stationed at Alcosebre (Spain), describes the observations which were made and the instruments which were employed at that station, and separate reports are pre
sented by M.M. M. Stefanik, G. Millochau, and J. J. Landerer, who were in charge of the several instruments.
The results, which are of only a preliminary nature, are too numerous to give in detail here, but all the observations, both visual and photographic, appear to have been successful.
M. E. Stephan, of the Marseilles Observatory, was placed in charge of one of the expeditions organised by the Bureau des Longitudes, and, accompanied by M. Borrelly, occupied the same station as Mr. Newall, at Guelma (Algeria).
The equipment of this expedition consisted of a telescope of 40 cm. aperture and an equatorial of 9.5 cm. aperture and 190 cm. focal length. A number of visual observations of the corona, the prominences, &c., were successfully made.
NOVA AQUILE No. 2.-Circular No. 106 of the Harvard College Observatory describes the discovery and subsequent observations of Nova Aquila No. 2. The Nova was discovered on a plate taken with the 11-inch Draper telescope on August 18 for the Henry Draper memorial series. spectrum, although faint, showed the lines H8, Hy, 4272, 4646, and HB very broad and bright, Hy and H8 having accompanying dark lines on their more refrangible edges. The helium line 4646 is slightly stronger than 4272, and the whole spectrum closely resembles that of Nova Persei No. 2, as photographed on March 30, 1901.
Some two or three hundred plates of this region are included in the Harvard series, and twenty-nine of them, taken before August 18, have been examined, but no trace of the Nova before that date has been discovered.
Two photographs showing the region half a degree square around the Nova, taken on August 15, 1903, and August 31, 1905, respectively, are reproduced in the Circular, and on comparing them it is at once seen that the Nova does not appear on the former, although it is quite a conspicuous object on the latter plate; stars of magnitude 15.7 are shown on the earlier plate.
Prof. Pickering's tabulated statement of the observed magnitudes of the Nova from August 31 to September 22 shows that this object gradually decreased in brightness from magnitude 10.41 on the first named date to magnitude 11-23 on the second. When first photographed the Nova's magnitude was about 7.0.
It follows from the Harvard observations that the Nova first appeared between August 10 and August 18, but it is hoped that, when the plates taken at Arequipa during that period arrive at Cambridge (Mass.), this interval may be greatly reduced.
STAR WITH A LARGE PROPER MOTION.-The method employed at Harvard College Observatory for the detection of variable stars, viz. the superposition of a photographic plate upon a glass positive of the same region, photographed on an earlier date, has led to the discovery that the star A.G.C. 6886 has a large proper motion. Whilst thus examining two plates of the Large Magellanic Cloud, taken on April 11, 1898, and December 5, 1904, respectively, Miss Leavitt found that this star had moved appreciably during the interval, and a comparison of the positions given in several of the older catalogues compiled since 1825 confirmed the fact.
The discussion of the data obtained from the comparison showed that the annual proper motion in R.A. is -0.066s., in declination +1"14, and along a great circle 1"-28.
The total number of stars shown on the original negatives is about 300,000, and it is probable that none of these, except A.G.C. 6886, has an annual proper motion exceeding three-quarters of a second (Harvard College Observatory Circular, No. 105).
OBSERVATIONS OF PERSEIDS, AUGUST.-The detailed results of the Perseid observations, made at the meteorological observatory at Pavia on August 8, 9, 10, and 11, are given in No. 8, vol. xxxiv., of the Memorie della Societá degli Spettroscopisti Italiani.
On the night of August 8-9 seven observers recorded 153 meteors, and determined the trajectories of 23 of them. The maximum horary rate occurred between oh. and th. (August 9), during which time 53 meteors were seen. On the succeeding night the watch lasted from 22h. to 3h. 7m.,
and the same number of observers saw 252 meteors, ci which they recorded the paths of 28. The maximum rate occurred during the last hour, when 93 meteors were seen. The third night produced 264 meteors, and of these the seven observers recorded the trajectories of 18 during their watch of 4h. 56m. The maximum horary rate of the whole shower, as observed at Pavia, was recorded during this watch, when 100 meteors were seen between 2h. and 3h. on the morning of August 11.
Of the 669 meteors seen during the three nights, 27 were recorded as being brighter than, and 139 as being equal to, the first magnitude, whilst " swift" and "white" the descriptive terms applied to the majority of them.
MATHEMATICAL AND PHYSICAL SCIENCE AT THE BRITISH ASSOCIATION. THE great number of astronomers present during the South African meeting caused astronomy to play a larger part in the proceedings of the section than it has done in recent years, and many of the most important communications and discussions were on astronomical subjects. The number of papers on pure mathematics and on physics was relatively small.
Of the mathematical papers, one by Prof. Harzer on ancient Japanese mathematics was of special interest. Prof. Harzer finds on examining ancient Japanese records and works that several of the theorems discovered in Europe during the seventeenth century were known at least as early to Japanese mathematicians. As an example, the expansion
I 2.4.6... 28 28(arc sin y)2= 6 B+ I 1.3.5 (28+1) due to Kowa Seki (1642-1708) may be quoted.
Mr. M. Cashmore showed how chess magic squares, i.e. squares of numbers which add up to the same amount along every path across the square in the direction of a rook's, a bishop's, or a knight's move, can be constructed by superposing on each other two types of subsidiary squares, which can be formed by simple rules.
Prof. Perry gave an account of the approximate method he had used to determine the stresses which occur in a winding rope carrying a cage when the upper end of the rope is suddenly stopped.
Mr. H. G. Fourcade described his instrument for stereoscopic surveying. It consists of a photographic camera which may be fixed in turn at the two ends of a base line with its axis perpendicular to that line. In front of, and close to, the sensitive plate a réseau scale on a glass plate is placed, and is reproduced on the two photographs taken. The two are examined together in a measuring machine similar to that used in stellar photography, and by means of micrometer screws any portion of the picture may be made to appear in relief and coincident with an index. The distance of that portion from the base line may then be determined from the micrometer readings. Each determination takes about two minutes, and with a base of 300 metres the probable error does not exceed 1 part in 1000 for a distance of 10,000 metres, and is less for shorter distances.
Prof. Perry raised the question of the teaching of elementary mechanics, and pointed out that the average boy who enters a technical college is so badly educated that his first year has to be wasted in the study of school subjects." Then three years are found to be insufficient to teach him " everything an engineer is likely to want in his profession," which many colleges foolishly attempt to do, and a fourth or even a fifth year is added. He urged that in teaching science to boys from nine to thirteen the methods of Mr. Barlow, of Sandford and Merton" fame, should be followed, until they know something of levers, weighing and measuring, specific gravities, barometers and thermometers, and of electricity and magnetism. At the age of fourteen a boy should know elementary algebra and trigonometry, should be able to differentiate and integrate, and apply the calculus. principles that if forces are in equilibrium their vector sum is zero, and the sum of their moments about any axis is
zero, should be presented to him from many points of view. Force should be taken as the rate of change of momentum. All these facts should be brought out and illustrated by experiment, and it should be the object of the teacher to turn out a pupil with a thorough grasp of mechanical principles, and not one crammed with formulæ which he soon forgets.
With the report of the Mathematical Association committee on the teaching of mechanics Prof. Perry is substantially in accord, although he differs from it in wishing to retain the term "centrifugal force" and to abolish the "poundal."
Lord Kelvin communicated a paper on the kinetic and statistical equilibrium of ether in ponderable matter at any temperature. If two small spheres, one covered with black, the other with white cloth, were placed in space at the earth's distance from the sun, the temperature of the black sphere would be greater than that of the white. If the spheres were at a distance from the sun 1000 times as great, and 999 other suns were scattered through space, all at about that distance from the spheres, the difference of temperature would be one-thousandth of the former difference. Dr. Chree has found, using thermometers, that in bright sunlight the difference of temperature is 1° C. to 3° C. On a starlight night we might therefore expect a difference of 0.001° C. or 0.003° C.
Dr. J. T. Bottomley described his experiments on the cooling of a lamp-blacked or silvered copper sphere in an evacuated spherical copper enclosure kept first at the temperature of liquid air, then, when the sphere has cooled, raised to the temperature of boiling water. Temperatures were observed thermoelectrically. The present results agree with those found previously by Dr. Bottomley, and do not support Stefan's law.
The writer reviewed the recent experimental work on the thermal conductivities of substances, and pointed out that the balance of evidence is in favour of many substances decreasing in thermal conductivity as their temperature is raised.
Mr. A. Word gave a résumé of the work done during the past year in the Cavendish Laboratory and elsewhere which justifies the conclusion that all substances are more or less radio-active.
Prof. Beattie described his observations on atmospheric electricity in South Africa, and his attempt to connect the observed conductivity of the air with other meteorological phenomena, an attempt which he considered had proved unsuccessful.
Communications on the meteorology of South Africa by Dr. Mill and by Mr. R. F. Rendall were read, and Prof. Beattie gave an account of the present state of the magnetic survey of the country, and exhibited charts embodying the results for the declination. Necessarily the work has had to be confined to positions near the railways, and it will be necessary to provide some means of extending the field of operations, especially along the western coast of South Africa. The association made a grant of 100l. towards the expense of this extension.
Great interest was shown in Sir David Gill's account of the geodetic survey in South Africa and the African arc of meridian. After the completion of the survey of Cape Colony and Natal in 1892, it became necessary to determine with greater accuracy the position of the twentieth parallel of longitude north of the colony at points where it formed the boundary of British and German territory. The work was placed in Sir David Gill's hands by the two Governments, and completed in 1903. At the same time, under the auspices of the Rhodesian Government, surveys of northern and southern Rhodesia were being carried out, partly in connection with the AngloPortuguese boundary. Since the war, surveys of the Transvaal and Orange River Colony have made steady progress, and the results so far obtained were embodied in the chart of South Africa exhibited by Sir David Gill. Throughout the work the bases taken were measured with the help of wires which were compared with a standard base 400 feet long before and after use. The discordance in the measurements of the Gwibi base of about 70,000 feet amounted in the aggregate to 1 part in 15 millions, and this was the base measured with least accuracy.
As a result, it appears that along the meridian of 19°
east longitude the curvature of the earth agrees with that given by Clarke's elements, but along meridian 26° east, and more markedly along meridian 30°, this appears not to be the case. A definite settlement of the question will only be possible after the connection of the Rhodesian triangulation with that of the rest of South Africa, a connection which will entail a cost of about 1600l. When this has been achieved, Sir David Gill will have made one step more towards the carrying out of his scheme for a great African arc of meridian extending from the Cape to Cairo, and by combination with the Russian-Scandinavian arc, a great arc from the Cape of Good Hope to the North Cape. The scheme has the hearty approval of Section A.
It is somewhat remarkable that at Cape Town the section should hear an account of a geodetic survey of a country within the Arctic circle, but the details of the geodetic survey of Spitsbergen given by its director, Dr. O. Backlund, proved of great interest. It was undertaken by the Swedish and Russian Governments, was carried out on the same lines as that in South Africa, and has given results of a high order of accuracy considering the difficulties of work in such a country. The values of g found at some of the stations in the mountainous parts of the country come out in defect by two or three figures in the fourth place.
One of the most important communications to the section was that of Prof. Kapteyn on star streaming. Prof. Kapteyn finds that the stars, the proper motions of which relative to the solar system have been determined, fall into two groups, one in which the motions take place in the main parallel to a line joining the sun to a point 7° south of a Orionis, the other with its motions parallel to the line joining the sun to a point 2° south of Sagittarii. If the motions of these two streams be referred to the centre of gravity of the whole of the stars considered, their directions must be diametrically opposite. One of the vertices of these motions in opposite directions Kapteyn finds is close to Orionis, and both lie in the central line of the Milky Way. Prof. Kapteyn does not hold that all motions must be in this line, but that there is a great preponderance of such motions, and that motions oblique to it get fewer the greater the obliquity. At this stage of the investigation he wishes to stand until further knowledge of the motions of stars in the line of sight has been obtained spectroscopically.
Dr. A. W. Roberts gave an account of the observations he has made during the past five years on the light fluctuations of certain southern binary stars, especially V. Puppis. He has succeeded in reaching a high degree of accuracy, and has determined the orbital elements of six stars by means of his observations, using the relations given by Rambaut. He finds the masses of two of the six systems to be 60 to 300 times, and the densities 0-00002 to 0.36 time, those of the sun. The large masses are somewhat exceptional, and Mr. Jeans suggested that the light curves of stars of pear shape would be found to agree with the observations made by Roberts. In support of this, Mr. Jeans gave an account of his investigation of the condensation of a gas occupying initially the whole of space about centres at distances apart approximately equal to that from the solar system to the nearer stars, and with the mass at each centre of the same order as that of the sun. Any one of these nuclei might take a spheroidal, ellipsoidal, or a pear shape, or separate into two parts, according to its velocity of revolution.
Mr. R. T. A. Innes gave an account of the state of double star astronomy in the southern hemisphere, and pointed out the importance of bringing up the observations in the southern to the same state as those in the northern hemisphere. He considers the position and climate of Johannesburg offer exceptional opportunities for the work, and suggested the provision of a telescope by the Transvaal Government. Sir David Gill supported this suggestion.
Of shorter communications it is only necessary mention a few, e.g. Prof. E. W. Brown's on the present state of lunar theory and the necessity of a new set of lunar tables, and Dr. Rambaut's on a new instrument for measuring stellar photographs, to show that in interest and importance the sectional work in South Africa in no way falls behind that of the meetings at home.
C. H. LEES.
CHEMISTRY AT THE BRITISH ASSOCIATION. THE papers contributed to Section B at the meetings
in South Africa were naturally more limited in number and in range of subject than is usual at ordinary meetings of the association, the majority of the communications having reference either to the chemical aspects of agriculture or to subjects connected with the gold extracting industry. On the other hand, a very active part in the work of the section was taken by the South African chemists, and, almost without exception, the reading of a paper was followed by an animated and interesting
At Cape Town, the first day of meeting was set aside for the discussion of agricultural and biochemical questions. As it had been arranged that the presidential address should be delivered at Johannesburg, its place was taken by Mr. A. D. Hall's report on recent developments in agricultural science, in which many subjects of special interest in South Africa were discussed. Dealing with the fixation of atmospheric nitrogen through the agency of bacteria, the author pointed out that a sharp distinction must be drawn between the use of pure cultures on old cultivated lands and in new countries, where leguminous crops are often being grown for the first time, and that the behaviour of the lucerne plant under bacterial infection in South African soils is worthy of careful investigation in view of its economic importance in all semi-arid countries. He directed attention to the need of a systematic series of soil analyses, with the ultimate object of making soil maps that shall be of service to the agriculturist, and indicated how much still remains unknown regarding the nutrition of plants and how great is the importance of research in the particular functions of the various constituents of the crop, as it is only through such knowledge that the quality of crops may possibly be influenced in desired directions. A brief discussion of the subjects of acclimatisation and cross-breeding brought to a close an address which aroused very great interest. Dr. Horace T. Brown then gave an account of his researches on the assimilatory processes of plants, in the course of which he described his method by which the assimilative power of leaves was measured for the first time under natural conditions. The quantity of carbon dioxide abstracted from the air by leaves of measured area was estimated in a special absorption apparatus devised for the purpose, and thus it was possible to deduce the amount of carbohydrate formed. The total solar radiation falling on the leaf was measured, and the proportion of the radiant energy of sunlight absorbed and transmitted by the leaf was also arrived at. The author's investigations showed that the rate of growth is not entirely dependent upon the amount of sunshine, but also on secondary causes. The business was brought to a close by a short paper by Dr. E. F. Armstrong on the role of enzymes in plant economy, in which the author directed attention to the fundamental similarity between the action of acids and that of enzymes, the distinction between them arising from the fact that enzymes act selectively in consequence of their power of associating themselves with the hydrolyte. The condition of the carbohydrate in solution is of primary importance, but this condition may to some extent be determined by the enzyme.
At the second day's meeting, Prof. H. B. Dixon gave a historical sketch of researches made on the propagation of explosions in gases, and discussed Berthelot's theory and his own "" sound wave theory on the mode of propagation. With the aid of the lantern he showed how he had followed photographically the flame from its initiation until the setting up of the detonation, and demonstrated the influence of the position of the spark and of the length of the column of exploding gases. He also described experiments now in progress on the specific heats of gases at high temperatures, and explained how the velocity of sound in a heated gas may be determined. In a second paper Prof. Dixon described the method he has devised for determining the atomic weight of chlorine by the direct burning of a known weight of hydrogen in a known weight of chlorine, the hydrogen, prepared by the electrolysis of barium hydroxide, being occluded in palladium, and the chlorine, prepared by the electrolysis of fused silver chloride, being weighed in the liquid state. The atomic
weight obtained is higher than that of Stas, but in close agreement with the recent results of Richards. Messrs. G. T. and H. W. Beilby gave an account of their experiments on the influence of phase changes on the tenacity of ductile metals at the ordinary temperature and at the boiling point of liquid air. They showed that when a wire of ductile metal is stretched to four or five times its original length by drawing it through the holes of a wire plate all the ordinary traces of crystalline structure dic appear, but the wire still consists of minute granules uf the crystalline phase embedded in a matrix of the amorphous phase. By lowering the temperature of drawing, the mixture approaches more nearly to the homogeneous amorphous state. Observations were made at 15° and at -180° on wires of copper, silver, and gold, which had been as completely as possible converted into the amorphous phase by wire drawing at the ordinary temperature, and in every case the tenacity observed was higher than any recorded by previous investigators for equally pure metals. The wires broken at the ordinary temperature showed no general stretching, but at the boiling point of liquid air all the wires stretched about 12 per cent. Dr. A. Midlay recorded his determinations of the viscosities of liquid mixtures at the temperature of their boiling points, which were made in the expectation that viscosity curves would be obtained similar in form to the boiling-point curves. In the case of benzene and methyl alcohol, the viscosities of which at the respective boiling points are nearly the same, the expectation appears to be realised, but where the viscosities of the pure liquids at their boiling points are not the same certain complications are met with.
The third day of meeting at Cape Town was set apart for communications from local chemists. Prof. P. D. Hahn gave an account of the remarkable thermal chalybeate spring at Caledon, in Cape Colony. With the aid of a tabular statement of the purity ratio of the most famous chalybeate springs, he showed that the Caledon water holds with the water of Spa the first place, but he pointed out that while the waters of most chalybeate springs are very low in temperature, the Caledon spring is unique in so far that the temperature of the water at the eye of the spring is 49° C. Mr. C. F. Juritz stated that for various reasons very scanty attention has hitherto been paid to purely scientific chemical research in Cape Colony, and gave an interesting account of several investigations made in the Government laboratory under his direction. A chemical survey of the soils of the colony (at present suspended for want of funds) has resulted in the examination of an area of 27,000 square miles, on an average one sample being taken for every 60 square miles. A number of the fodder plants of the Karroo have been examined as regards their nutritive value, estimations of tannin in the barks of various trees have been made, poisonous prin ciples have been extracted from some indigenous plants, and an alkaloid resembling quinine therapeutically, but differing from it chemically, has been extracted from the umjela or quinine tree, which abounds in the Transkei. Clays have been found in various parts of the colony some of which compare favourably in chemical composition with the best fire clays, and mineral pitch has been observed in certain localities. Dr. H. Tietz, in a paper on the character of Cape wines, explained that at the Cape grapes always become perfectly ripe, and thus contain more sugar and less acid than the grapes of the wine-producing countries of Europe. Notwithstanding this, a standing reproach against Cape wines is based on the contention that they contain more acid than European wines. The author investigated this matter on some 30 samples of different Cape wines, and found that the allegation cannot be upheld.
At Johannesburg the proceedings of the section were inaugurated by the delivery of the address of the president, which was of quite exceptional interest. It was followed by a paper by Mr. H. F. Julian, in which an investigation of the part played by oxygen in the dissolution of gold by cyanide solutions was described. The author arrived at the conclusion that free oxygen plays no primar part in the reaction, any assistance given being of a secondary nature, and that, as a matter of fact, it exert‹ a retarding influence. According to his experiments, while the balance indicates that free oxygen is of material assist