a strong magnetic power. This action tends to augment the resistance of the gaseous substance to the transmission of electricity, by condensing the gaseous filaments, and has in particular the effect of rendering luminous the obscure part of the column, by contracting the previously too much dilated gas which occurs there. Lastly, the attention of M. de la Rive was especially drawn to the rotatory and expansive action of magnetism on the electric discharge. He has succeeded in obtaining, in regard to this point, certain very constant facts, such as those relative to the duration of the rotatory movement of the discharge, which varies with the direction of the current, the nature of the gas, and its degree of density. He has also remarked the very great difference which the phenomenon presents, according as the rarefied gas is dry or contains vapor of water or of alcohol. In the first case, the luminous discharge expands under the influence of magnetism into a sheet which forms the surface of a sector, or even that of a full circle when the gas is very much rarefied. In the case in which vapor is present in the rarefied gas, the discharge, instead of expanding, divides into a greater or less number of small partial jets at equal interspaces, forming, as it were, a star animated by a movement of rotation around its centre. These phenomena, and others of the same kind, have led M. de la Rive to establish a difference between permanent gases and vapors, in reference to the point of cohesion, or rather their molecular constitution. The author terminated the reading of his memoir with some general considerations on this extensive subject; announcing that, for the present, conclusions too absolute would be premature, and that he abstains from presenting them until he shall have completed his researches by extending them to a greater number of gaseous substances.

If we have enlarged a little more than is usual in an analysis of the memoir of M. de la Rive, we find a justification, not only in the importance of the subject, but in the circumstance that the results which he obtained have been heretofore published only in fragments. The entire memoir is about to appear in the seventeenth volume of the Memoirs of the Society, now in the press.

It should be added, that we owe to M. de la Rive the model of a new system of Grove's apparatus. The modification which he has introduced into the battery of that physicist is essentially calculated to render its management more commodious and prompt. His instrument, which is extremely manageable, and is furnished with conductors of alumina, possesses the advantage of requiring little manipulation, and of rendering superfluous the removal of the nitric acid; the same acid suffices for the service of several days and many experi ments. With the help of a single pair of this battery, M. de la Rive has been able to repeat all the principal experiments of the electro-dynamics of Ampéreexperiments which usually require five or six pairs of Grove or of Bunsen.

Besides some verbal communications by Professor Wartmann relative to electrical phenomena, particularly to the limit of pressure which permits a spark to pass through a gaseous medium, as well as to the influence which the state of tension of a gaseous medium exercises on the passage of a current, the savant just named engaged the attention of the society by an account of some of the principal subjects discussed in the last reunion of the British Association at Cambridge, at which he was present. Among the communications made on that occasion, M. Wartmann cites more particularly the observations of M. Nasmith relative to the structure of the sun. To avoid the inconvenience of a too great light, M. Nasmith, instead of introducing the solar rays directly into the eye, places near the object glass a lens which is plane on the side next the eye, but concave on the opposite side, so as to disperse the luminous rays and allow the study of only the quantity of light reflected by the plane surface. The author has thus been able to ascertain that towards the hour of noonday

*A full translation of this interesting memoir is given in this report.-See page

the luminous envelope of the sun presents a great number of spindle-shaped images, which might be compared to willow leaves strewn confusedly over its surface. Of these M. Wartmann has presented to the Society a photograph taken from the original designs of M. Nasmith. These images seem to be displaced one by another, sometimes parallel to their axis, sometimes by an angu lar movement. The preceding observations have been confirmed by M. Pritchard, who announces that they may be repeated with a good telescope of from three to four inches. M. Wartmann also gave an account of experiments in telegraphic electricity by M. Wheatstone, which he witnessed, and by which it is practicable to obtain despatches written with extraordinary rapidity.

The same physicist communicated to the Society a note relative to an electrical phenomenon observed by M. Alizier, teacher at Geneva, July 24, 1856, on the summit of the Oldenhorn. Of a sudden the staves borne by M. Alizier and the persons who accompanied him began to sound in the manner of the posts of the telegraph. In a few moments a heavy storm of hail descended.

Professor de la Rive, on his return, in May, 1863, from a sojourn in Paris, reported to the Society several new scientific facts which he had gathered. He drew attention, in particular, to an investigation of M. Helmholtz, by which that savant had arrived, simultaneously with M. W. Thompson, at the conclusion that the earth cannot be liquid in its interior. He also thinks himself entitled to affirm that it is not necessary to recur to the hypothesis of aerolites falling continually into the sun, in order to explain the persistence of the high temperature of that body. It suffices to admit that the sun, having become heated by an undetermined cause, is now growing cold with extreme slowness; for, according to M. Helmholtz, the calculations heretofore made greatly exaggerated the rapidity of refrigeration in regard to that body, because they neglected to take account of an important element, namely, that the sun diminishes in volume as it grows cooler, and that this contraction must develop new heat.

M. de la Rive presented to the Society, in the name of his son, M. Lucien de la Rive, a memoir on the number of independent equations in the solution of a system of linear currents. This memoir, being wholly mathematical, is not adapted to analysis.

Professor Marcet has continued to impart to the Society many facts relative to nocturnal radiation; among others, to an altogether abnormal refrigeration of the surface of the ground, and of the stratum of air in immediate contact with it, which he has remarked during the first days of March in localities turned towards the north, not only at the hour of sunset, but even during the warmest hours of the day. The author attributes this extraordinary cooling of the surface to the concurrence of several atmospheric circumstances, but more especially to the extreme dryness which had prevailed for some time, and which, as Tyndall has proved, peculiarly facilitates the radiation of terrestrial heat.*

M. Marcet has taken advantage of the residence of his son in Australia, to induce him to repeat at Queensland, under the 22d degree of south latitude, the experiments on nocturnal radiation, which have been recently made in our temperate climates. It would seem to result from these experiments that the phenomenon of the increase of temperature at certain periods of the day, when we ascend some feet above the surface of the carth-a phenomenon so well authenticated in our temperate climates-is not remarked in the regions of the torrid zone either at the rising or setting of the sun; or if it takes place, it is in a degree scarcely sensible, hardly ever exceeding O°.4 Cent. M. Lucien de la Rive has recently made some observations in Egypt, on the banks of the Nile, which would appear to lead to an analogous result. M. Marcet explains

* See Archives des Sciences Physiques et Naturelles, April, 1863.

this apparent anomaly by attributing it to several causes, but more particu larly to the great quantity of water, under the form of elastic vapor, held by the atmosphere in tropical regions, especially in countries but little remote from the sea-vapor which, it is known, possesses the property of intercepting in a high degree the dark heat emitted by the ground, and which would thus contribute to render so much less apparent the effects produced by the nocturnal radiation.

Communications on chemistry proper have this year been less numerous than usual. We have scarcely anything to cite but some remarkable researches of Professor Marignac on the tungstates, the fluo-tungstates, and the fluoborates. The subject, although of great importance, and treated in a masterly manner, is too special to allow of my presenting here even a summary analysis. We may, besides, direct the reader for a detailed extract of the memoir to the comptes rendus of the Academy of Sciences, in anticipation of its appearance in extenso in early numbers of the Annales de Chimie et de Physique.

Dr. W. Marcet has drawn the attention of the Society to investigations made by him on the digestion of fats, particularly on the mode in which the emulsion of those substances is effected by means of the bile, and probably also of the phosphates, which occur abundantly in animal food. The same chemist also communicates experiments, which he has recently undertaken, on the composition of the gastric juice, and on the changes which it undergoes as to the degree of acidity during the act of digestion.

NATURAL SCIENCES.

The natural sciences, and more especially geology and paleontology, have this year had a large share in the labors of the Society. We should mention, in the first place, several important communications of Professor A. Favre; and, first, his geological chart of portions of Savoy, Piedmont, and Switzerland, in the neighborhood of Mont-Blanc-a chart drawn on a scale of 150000, and which is the result of persevering and conscientious labors pursued since 1840. M. Favre has also presented us with the geological chart of the Jura mountains pertaining to Basle-the first published at the expense of the confederation, under the care and direction of M. Müller. It is designed on a scale of There is reason to fear, however, that the enterprise cannot be continued in such wide proportions, and that it will be necessary to return to the scale of The chart is accompanied by a publication in two series—one for the Jura, the other for the Alps.

M. Favre also read to the Society a memoir containing a detailed description of the mountain of the Voirons, of which he has determined the succession of the different strata. This memoir will soon appear in the text which will accompany the chart of Savoy.

The same geologist read to the Society a critical analysis of MM. KoechlinSchlumberger and Schimper on the transition deposit of the Vosges a deposit referred at present to the old carboniferous series. He also presented, in the name of M. Studer, a geological memoir on the Balligstock and the Beatenberg, situated on the borders of the Lake of Thoune-a memoir which has been published in the Archives of the Physical and Natural Sciences.

Professor Pictet read to the Society a note containing critical observations on the subject of a new stratum, which M. Coquand proposes to introduce into the series of cretaceous formations-a stratum already known under the name of "alpine neocomian," and to which he proposes to give that of "barémian,” considering it as the equivalent of the yellow stone of Neuchâtel. M. Pictet, without disputing the propriety of a new name, does not admit, between the barémian and the yellow stone of Neuchâtel, so precise and restricted a parallelism.

The same savant called the attention of the Society to an alleged reptile with feathers, found in the jurassic of Solenhofer, and described by M. Wagner as possessing at once the tail of a reptile and the feathers and feet of a bird. This fossil has been acquired for the British Museum by M. Owen, who will soon publish a detailed description of it.

The Society has continued to keep itself informed of the facts relative to the "fossil man." Its interest has been particularly excited by the discovery of the human jaw-bone of Moulin-Quignon, near Abbeville. M. Pictet, who took occasion very recently to study, at Paris, this bone, and the hatchets which accompanied it, has set forth to the Society the reasons which seemed to him to render the authenticity of those objects incontestable, notwithstanding the doubts at first expressed on this subject by eminent paleontologists. More recently we have learned with much interest that a sort of scientific congress had been convoked at Paris, and the authenticity admitted with unanimity. It remains to solve the question of antiquity-that is to say, to decide what place the deposit of Moulin-Quignon should occupy in the series of quaternary and modern formations.

M. Renevier has communicated to us a photographic view of the Diablerets, geologically colored, and has, at the same time, given to the Society an account of some recent geological excursions in the vaudese Alps. He has been enabled to complete the series of jurassic formations in this district by the discovery, in the Diablerets, of a stratum of bajocian, (inferior oolite,) and of a stratum of bathonian, (greater oolite,) the first being characterized by a gigantic fucoid. Finally, M. Renevier announces grains of "chara" in the nummulitic of the Diablerets.

We arrive now at organic natural history, and it remains to speak of botany and zoology.

Botany.-Professor De Candolle has presented to the Society several interesting communications relative to vegetable physiology and to botany proper; particularly a paper on a new character observed in the fruit of oaks, and on the best division to adopt for the genus "Quercus;" a memoir entitled Studies on species, occasioned by a revision of the family of Cupulifera, in which the author discusses the system of Darwin, and the theory, applied to the vegetable kingdom, of a succession of forms proceeding from the deviations of an anterior form. Both these memoirs having been published in the archives of the physical and natural sciences of the Bibliotheque Universelle we shall here content ourselves with indicating them to savants who are interested in questions of this kind.

Besides the original memoirs just cited, M. de Candolle brought to the notice of the Society some interesting results of observations made by M. Schubler "on plants cultivated in Norway." The author has shown us in what degree the deficiency of heat, in northern regions, appears to be compensated by the prolonged action of the light due to the length of the days; to such an extent that, in proportion as we advance towards the north, the coloration and sapidity of plants seem to increase rather than diminish in intensity.

M. de Candolle has also drawn attention to two memoirs of Dr. Hooker. The first relates to a plant discovered on the African continent, opposite Fernando-Po, to which he has given the name of Welwitschia. This plant, whose trunk is a cone of little height, surmounted by a torous (bossclé) table attaining a diameter of six feet, presents the singular character of having but two leaves, which are indeciduous cotyledons. It is the only vegetable known whose cotyledons are not caducous. The second memoir of M. Hooker relates to the celebrated group of cedars of Lebanon, which is found to be established on the moraine of an ancient glacier, and which this botanist visited in 1860. M. Hooker is inclined to think that, in the present circumstances of climate, this tree could, with difficulty, establish itself on the mountain where it is found, and pronounces

the opinion that the old cedars which now exist there are but the remains of an ancient forest, dating from an epoch more favorable to the development of the species. It is certain, in the mean time, that the cedar of Lebanon, that of the Himalaya, and that of the Atlas present varieties which it is difficult to distinguish from one another. Hence M. Hooker is disposed to admit that they all descend from one primitive form, which has spread itself over a vast region when the climate was more temperate than it is at present.

To Rev. M. Duby we are indebted for a note relative to observations made at Bombay, on a champignon or fungus which attacks the feet of the natives, and produces a malady known in the country under the name of "podelcoma mycetoma." The bones of the foot and lower leg are gradually perforated through and through, and the champignon, which bears spores very similar to those of the oïdium, lodges in the cavities thus formed, under the shape of a spongy mass. M. Duby has also occupied our attention with the very ingenious observations of M. Darwin on the mode of fecundation of the red flax." The same botanist also announces that he has observed in the Callistachys linearis a very remarkable movement of the inferior leaves which, at the decline of day embrace the stem, while the superior leaves embrace the ear.

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Zoology and Physiology.-Dr. Dor called the attention of the Society to a new theory of Daltonism, or rather to an old theory of Young, to which there seems to be a tendency to recur at the present time. Agrecably to this theory there exist in the retina three descriptions of nervous fibres; the first sensitive to red, the second to green, the third to violet. Daltonists, then, would be those in whom one of these orders of fibres is completely paralyzed. M. Dor has also proposed a new scale of characters for measuring the distinctness of vision.

M. Victor Fatio presented to the Society a specimen of a lizard of the Alps called "Lacerta nigra," regarded by some authors as constituting a particular species. M. Fatio is rather disposed to consider it as being but a simple variety of the "Lacerta vivipara," and he adduces the reasons which lead him to hold this opinion.

The same physiologist read to the Society a note on the habits of the "pléobate cultripede," of the coasts of Brittany. He has ascertained that this batrachian is a nocturnal animal, which buries itself during the day in the sand, and remains there till night in a state of complete immobility. M. Fatio has also communicated to us a plan of geographical distribution, designed to form the basis of an extensive work, which he has undertaken with the view of making a complete catalogue of the vertebrata of Switzerland.

To complete what we have to say on organic natural history, we should mention an interesting notice by M. Muller, relative to the recent modifications which the theory of cellular organization has undergone through the influence of the labors of MM. Brücke and Max. Schultze; and a communication of M. Claparede, in which that physiologist renders au account of some epidemic instances of "trichinus spiralis" lately authenticated in Germany, and more especially in Saxony. It is now known that the larva of this parasite continues to live in the flesh of the hog when insufficiently smoked. Now, a single pair of these animalcules, arriving at maturity in the human intestine, suffice to infect with larvæ all the muscles of the body, and to occasion the gravest consequences, sometimes even death. The danger of such an infection is now so fully realized that the inhabitants of Planen, in Saxony, have established at their slaughter-house an official, provided with a microscope, and have prohibited the sale of hogs whose flesh has not been previously examined with the help of that instrument.*

* For an appendix to this part of the report see the end of this article.