Carbonic Acid and Glaciation.—In a paper on Hypotheses bearing on Climatic Changes, Prof. T. C. Chamberlin takes up a suggestion of Tyndall's that the periods of terrestrial glaciation might be dependent upon the carbon dioxide of the atmosphere, the peculiar competence of which to retain solar heat he had demonstrated. Following out the doctrine of atmospheric loss on its own lines, although only in a tentative way as yet, he seems to find a rhythmical action that may in part explain the glacial oscillations. The idea, he says, hinges on the action of the ocean as a reservoir of carbon dioxide, and on the losses of the organic cycle under the influence of cold. Cold water absorbs more carbon dioxide than warm water. As the atmosphere becomes impoverished and the temperature declines, the capacity of the ocean to take up carbonic acid in solution increases. Instead, therefore, of resupplying the atmosphere in the stress of its impoverishment, the ocean withholds its carbon dioxide to a certain extent, and possibly even turns robber itself by greater absorption. So also, with increased cold the progress of organic decay becomes less active, a greater part of the vegetal and animal matter remains undecomposed, and its carbon is thereby locked up; and hence the loss of carbon dioxide through the organic cycle is increased. The impoverishment of the atmosphere is thus hastened and the epoch of cold is precipitated. With the spread of glaciation the main crystalline areas whose alteration is the chief source of depletion become covered and frozen, and the abstraction of carbon dioxide by rock alteration is checked. The supply continuing the same, by hypothesis, re-enrichment begins, and when it has sufficiently advanced warmth returns. With returning warmth the ocean gives up its carbon dioxide more freely, the accumulated organic products decay and add their contribution of carbonic acid, and the re-enrichment is accelerated and interglacial mildness is hastened.

Additions to the Missouri Botanical Garden.—We learn from the ninth annual report of the Missouri Botanical Garden that while the decorative features were maintained in 1897 in about the same manner as heretofore, considerable additions have been made in certain classes, especially orchids, and the collections of cultivated species, with their named varieties, are now estimated to number about five thousand. Circumstances made possible material additions to the contents of the herbarium; and, besides the purchased current collections, rather larger and more numerous than usual, the garden has secured the herbarium of the late J. H. Redfield, very rich in earlier collections representing the flora of the United States; the herbarium of the late Dr. J. F. Joor, containing 4,133 specimens, and largely adding to the representation of the flora of Louisiana and Texas; the interesting herbarium of Gustav Jermy, of San Antonio, Texas, containing a very full set of Carpathian plants and a nearly complete local flora; the important pre-LinnÆan herbarium formed by Boehmer and Ludwig; and a Chinese collection by Dr. A. Henry. Even larger additions were made to the library. The instruction of garden pupils was continued, and the garden was visited by several research students. Among the scientific papers accompanying the report and bound with it are those of C. H. Thompson on American LemnaceÆ; N. N. Glatfelter on Salix longipes; H. C. Irish on the Genus Capsicum; A. S. Hitchcock on Cryptogams collected in the Bahamas, Jamaica, and Grand Cayman; J. N. Rose on Agaves; C. H. Thompson on Cacti Anhalonium; and seven shorter papers under the heading of "Notes and Observations."

The Indian Idea of the "Midmost Self."—In attempting to explain the significance of a pentagonal stone dodecahedron with vestiges of figures on it found near Marietta, Ohio, Dr. J. C. Morris assumed that, besides the Aryan idea of three dimensions of space, there is, to the Indian and to the Eastern mind, another—the fullness. "It is not the length and breadth and thickness of a cube, for instance, but the whole of it, which is as much to be considered as any one of its sides. A cube would therefore be represented numerically by seven, a dodecahedron by thirteen. Among the Mexicans the thirteen lunar months would thus correspond in the year with the twelve zodiacal signs and the earth which passed under and embraced them all." Again, the five digits came to be a measure of man's power or individuality, and thus a sacred number. A pentagonal dodecahedron, then, might be the emblem of the world; and the best time to be active in some contemplated pursuit might be shown by the zodiacal sign that came uppermost when the dodecahedron was thrown or rolled with appropriate ceremonies. As Mr. Frank H. Cushing interpreted the doctrine at the same meeting of the Anthropological Society, when the primitive man contemplates or considers himself or anything in its relation to space or the surrounding directions, "he notices that there is ever a front or face, a rear or back; two sides, or a right and a left; a head and a foot, or an above and a below; and that of and within all of these is himself or it; that the essence of all these aspects in anything is the thing itself—that is, the thing that contains their numbers or sum, yet is one by itself. This is indeed the very key to his conception of himself and of anything in relation to space and the universe or cosmos. He observes that there are as many regions in the world as there are aspects of himself or sides to any equally separate thing; that there are as many directions from him or his place in the world (which is his 'midmost' or place of attachment to the Earth-mother), or from anything in the world (which is its midmost or natural station), toward these corresponding regions. Hence to him a plane would be symbolized not by four, but by five—its four sides and directions thence, and its central self—as was actually the notion of the prairie tribes; a cube, not by six, but by seven, as was the notion of the valley Pueblos and Navajos; a dodecahedron, not by twelve, but by thirteen, as was the notion of the ZuÑis, the Aztecs, and apparently—from this example—of the mound builders as well."

The Bactrian Camel for the Klondike.—The great Siberian or Bactrian camel is recommended by Mr. Carl Hagenbeck, the famous Hamburg importer of wild beasts, as the best animal for the Klondike climate. It is at home in the coldest regions, can carry or go in harness, can cross mountains or traverse valleys, and is so easily supplied that Mr. Hagenbeck can undertake to deliver any number in New York, duty paid, for three hundred dollars each. It can endure thirst and long spells of hunger as well as freezing cold, and is not too delicate to make its bed on the snow. It sheds its coat before the summer heat, but as the cooler weather of the fall comes on "it grows a garment of fur almost as thick as a buffalo robe and equally cold-resisting. It is far more strongly built than the southern camel. It does not 'split' when on slippery ground, though it falls on moist, wet clay which yields to the foot. On ice and frozen snow it stands firmly, and can travel far." It is said that an excellent cross can be made between the male Bactrian and the female Arabian camel; but when the parentage is reversed the progeny is useless. General Harlan is said to have marched two thousand Bactrian camels four hundred miles and crossed the Indian Caucasus in ice and snow, with the loss of only one animal, and that by an accident. This camel is native to the high plateaus, steppes, and deserts of Mongolia and South Siberia, and it has been found wild on the plain of Tsaidam, maintaining itself in this "arid, cold, and waterless region, where the herds are said to travel seventy miles to drink. Nothing," we are further told, "but too much comfort or a damp climate seems to hurt it. For food it prefers dry, salty plants and bushes and grows sick and lean on good pasture. The salty efflorescence of the steppes is eagerly eaten by it, and in this country it prefers dry food, especially wheat straw and hay. Prjevalski's camels would eat almost anything—straw, bleached bones, old pack saddles, straps, and leather. The Mongols told him of camels which had been without food a long time, and then devoured an old tent belonging to their owner. They even ate meat and fish, and one of the traveler's camels made a meal of the bird skins ready for stuffing."

Nicaragua and its Ferns.—Tropical America is described by B. Shimek, in a paper on the Ferns of Nicaragua, as the fern paradise of the earth. "No other corresponding division of the earth's surface," he says, "presents as great a total number of species, or as many species which are peculiar to it. Nowhere else is the great variation in form and size, in structural characters and habits of growth, and in the arrangement and character of the reproductive organs, better shown than here. This richness in the fern flora, exhibited in almost unlimited variety, is, no doubt, accounted for by the topography and contour of that part of the American continent which lies within the tropics. It is narrow when compared with the continents of the Old World, and it contains high mountain chains, which form its longest axis. Its narrow form brings all of it more or less within the influence of the adjacent oceans, which furnish to most of it an abundance of moisture. Its high mountains supply all the conditions effected by altitude, and, moreover, cut off the otherwise abundant moisture from certain areas. We have thus within comparatively restricted limits all the possible degrees of moisture and temperature, and the effect of environment finds abundant expression in the great variety of fern structures." After palms, ferns form the most conspicuous feature of tropical vegetation, and in size they vary from species only a fraction of an inch high to splendid tree ferns or vines single fronds of which are more than thirty feet long. In texture "some rival the flimsiest lace, while others develop thick, leathery fronds.... In habit the variation is fully as great. In western Nicaragua, for example, where there is a distinct dry season, ferns growing on bare volcanic rock become so dry that they may be ground to powder between the fingers, and yet they retain life; while in the eastern part, with its deep jungles in which perpetual shade and moisture prevail, the more delicate as well as the more gorgeous forms have full opportunity for the development of their many peculiarities." In a very small territory of Nicaragua, including a strip along the San Juan River in no case extending more than six miles away from it, and in the little island of Ometepe in Lake Nicaragua, Mr. Shimek, in less than four months, while engaged in general botanical work, collected more than a hundred and twenty species of ferns; and yet only about one fifth of one hundred and twenty-one species recorded by Fournier, two fifths of one hundred and thirty-five species credited by Hemsley to Nicaragua, and two fifths of those reported by Baker and Hemsley from adjacent Costa Rica, occur in his list.

Wave Length and other Measurements.—Describing the measurement of absolute wave length before the Astronomical and Physical Society of Toronto, Mr. A. F. Miller remarked that a somewhat incorrect idea prevailed as to the smallness of the space occupied in the performance of luminous undulations; in fact, some people seem to regard the wave length of light as something almost inconceivably small. Really, however, we are familiar with much smaller dimensions. For instance, the author had found from actual measures that the wave length of one of the characteristic lines in the spectrum of sodium vapor was very nearly equal to 1/42000 of an inch. The thickness of ordinary gold leaf is given as 1/282000 of an inch, from which it becomes evident that the wave length of sodium light, which is an average wave length for the visible spectrum, is six and a half times as great as the thickness of gold leaf. Such a dimension as 1/42000 of an inch could readily be measured by a suitable micrometer; but of course the waves of light, as well as the ether particles by which they are transmitted, are entirely invisible, and even were this otherwise the frequency of the undulations is so inconceivably great that the actual phenomena of the movements could never become perceptible. In measuring the absolute wave length, therefore, we are forced to take the indirect method of observing the results of undulations in cases where, by a suitable arrangement of the experiment, equal and opposite phases of vibration are made to arrive simultaneously at the same spot, so producing phenomena of interference.

The "Causses" of Southern France.—It is surprising to find existing, in a country so old and supposedly so familiar as France, a region similar to our Colorado plateau, full of caÑons, caves, and cliff dwellings, until recently almost unknown and wholly unexplored. Yet such is the region of the Causses, described and illustrated with a striking series of lantern views, before the American Association for the Advancement of Science, by the well-known cave explorer, Dr. H. C. Hovey, of Newburyport, Mass. The local name Causse, derived from the Latin calx, lime, is applied to a limestone area, and here to a limestone plateau. Along the western slope of the CÉvennes Mountains lies an elevated table-land, chiefly of Jurassic limestones, which had been cut and carved by the streams, especially the Tarn and its affluents, into a group of high plateaus separated by deep caÑons. The cliffs of the Tarn Valley are from one to two thousand feet and even more in height, and with their precipitous sides and the brilliant and varied coloring of their strata are not unworthy of comparison with our own great caÑon regions of the West. At some points, where the beds are markedly unequal in hardness, the weathering process has resulted in structures as remarkable as Monument Park or the Garden of the Gods. Such is the "rock city" known as Montpellier-le-Vieux, at the junction of the JontÉ and the Durbais, on the Causse Noir. This strange area of natural ruins covers some two thousand acres with a fantastic similitude of castles, palaces, streets, and temples. It seems surprising that a country so picturesque for the tourist and so interesting for the geologist should have remained almost unknown till the present time. Fine roads pass over and around it, but they avoid the wild and rugged portions that possess such scenic interest, and leave the Causses—as they have been for ages—barren solitudes, occupied only by shepherds with their huts and flocks. The people, also, as is so often the case in such regions, have a superstitious dread of the deeper caverns and the seeming ruins, and do not lend themselves readily to exploration. The cliffs are full of caves, some of which—the more accessible and simple—are used as sheepfolds, and even in some cases inhabited, but the wilder ones are held in dread. It seems that cliff dwellings are actually still in use to some extent in this region. The French SociÉtÉ de SpÉlÉologie has now for some years been investigating the Causses with great interest. Ere long this will become a favorite region for tourists; but at present one must leave all ordinary facilities of travel and take to canoes and mules. This was done by Dr. Hovey and his party, under the leadership of M. Edouard A. Martel, of Paris, who has been one of the most active explorers. They entered and traversed many remarkable caves, some never before visited, and some that have been previously explored by M. Martel and others of the sociÉtÉ. One of these, known as the Baumes Chaudes, is a great triple cavern, one of the main branches of which had yielded a large number of prehistoric skeletons to Dr. PruniÈres, of Marvejol. In the third division are a number of deep pits, locally called "wells," from forty to a hundred and thirty feet deep; these communicate with lower passages and subterranean streams. They are death-traps to animals, the remains of which, of many kinds and in all stages of decomposition, accumulate at the bottom, and are gradually covered by stalagmitic deposits. Another remarkable cave was discovered and named after its daring and enthusiastic explorer, M. Louis Armand, of Paris. It can only be entered by a "well" two hundred and forty feet deep, and below this lies another of still greater depth. The party was provided with rope ladders for use in such places; and the intrepid investigator who essayed the descent went down, by actual measurement, six hundred feet from the surface. He described the stalactites as magnificent. Both from a geological and an archÆological point of view this account was of unusual interest. Dr. Hovey had many beautiful views of the caÑons and the cave openings in their walls; while his observations, and those of the SociÉtÉ de SpÉlÉologie, are very curious as to the persistence, in this strangely overlooked region, of conditions closely akin to what are usually called "prehistoric" times.

Molecular Asymmetry and Life.—Speaking in his presidential address to the Chemical Section of the British Association on Stereochemistry and Vitalism, Prof. A. R. Japp expressed the conclusion that "the production of single asymmetric compounds or their isolation from the mixture of their enantiomorphs [or opposite forms] is, as Pasteur firmly held, the prerogative of life. Only the living organism, with its asymmetric tissues, or the asymmetric productions of the living organism, or the living intelligence with its conception of asymmetry, can produce this result. Only asymmetry can beget asymmetry. The absolute origin of the compounds of one-sided asymmetry is a mystery as profound as the absolute origin of life itself. The two phenomena are intimately connected.... No fortuitous concourse of atoms, even with all eternity for them to clash and combine in, could compass this feat of the formation of the first optically active organic compound. Coincidence is excluded, and every purely mechanical explanation of the phenomena must necessarily fail. I see no escape from the conclusion that at the moment when life first arose a directive force came into play—a force of precisely the same character as that which enables the intelligent operator, by the exercise of his will, to select one crystallized enantiomorph and reject its asymmetric opposite. I would emphasize the fact that the operation of a directive force of this nature does not involve a violation of the law of the conservation of energy."

Dr. Russell's Photographic Researches.—At the recent meeting of the British Association at Bristol, Dr. W. T. Russell gave, before the Chemical Section, some further information regarding his recent researches on the surprising action exerted by certain substances in the absence of light on photographic plates. The Journal of the Society of Arts gives some of his more striking results: "Some ordinary type, a portion of the cover of Punch, and the wrapper of a packet of tobacco produced strongly defined pictures; the last mentioned was particularly interesting, inasmuch as the red ink had proved active, the blue inactive. Strangely, writing ink (old-fashioned) is quite inactive, and paper having writing on it in ink, even over a hundred years old, when placed between a sheet of active material and a sensitive plate, yielded a picture in which the writing appeared quite distinctly, white on black, in spite of the original being in some cases indistinct; ferrous sulphate behaves like ink. The list of materials that are active is very long, and includes wood, which gives a picture of the grain and knots. Many metals are active, but zinc is very active only when bright, so that a dirty sheet of zinc rubbed with sandpaper gives a picture of the scratches. Many alloys are also active, pewter and fusible metal being two of them, and curiously some brasses are, while others are not. The effective agency that passes from the material to the sensitive plate shows peculiarities. It passes through gelatin, gutta-percha, celluloid, collodion, wet gum arabic, and some paper, while other paper, glass, minerals transparent to light, and many other substances are opaque to these emanations, and some striking effects were exhibited demonstrating the interference of these opaque substances when interposed between an active substance and the sensitive plate. For instance, a five-pound note placed printing downward on the sensitive plate gave a picture of the printing inscription, but when placed under a zinc plate with the printing toward the zinc plate it gave a picture of the opaque paper with the water marks distinctly showing, and, what is still more astonishing, the zinc plate, after contact with the note, itself yielded a picture of the inscription, showing that the influence from the ink had passed to the zinc plate. It was noteworthy that the signature was not in writing ink. A cutting from the Times, the paper being transparent, showed a picture of the printing on both sides; the picture, moreover, was reversible, showing that a perfect picture of both sides of the paper had been impressed on the one plate. This interesting phenomenon is, however, not quite explained, but the great amount of work he has done leads him to the provisional opinion that the effect is due to the evolution of hydrogen peroxide."

Scientific "Trade Hunting."—The recent movement in England toward the establishment by the Government of a commercial intelligence office for the securing and diffusion of information regarding foreign trade has given rise to considerable discussion among the English trade papers. The business of the office is to be the gathering of general information of interest and value to the English merchant with a foreign trade, and especially of pointing out new ways for the extension of foreign commerce, and calling attention to possible new markets for English goods. A number of schemes have been proposed, among others that of sending an expert once every year or two to the different foreign "trade areas," for the purpose of collecting information and samples, and of giving a trustworthy estimate of its commercial prospects; another, that of extending the consular reports in such a manner as to compass the same ends. There is considerable opposition to the scheme from some branches of business, where it is held that no one is so likely to get hold of useful information as the trader himself, and that the publishing of such Government reports as the scheme contemplates would result in giving the information to foreign as well as English traders, and thus negative whatever advantage might come to the English merchant from his individual discovery of a valuable market.

Dr. Neufeld.—The London Times of September 13th gives the following account of the career of Dr. Neufeld, who has just been delivered from captivity in Omdurman by the English forces: "Karl Neufeld studied medicine at Leipsic University, and went early in life to Egypt, following first his profession as a medical man and subsequently as a merchant. At the beginning of the eighties he had a practice at Keneh, Upper Egypt, where several Germans and also natives of his own home saw him. Subsequently he set up as a merchant at Assouan. After the fall of Khartoum and the firm establishment of the Mahdi's power at Omdurman, Neufeld seems to have formed a scheme for opening up commercial intercourse with the closed Soudan, for he equipped a caravan with which he proceeded to Berber, which was then in the hands of Osman Digna. The latter sent the German, whom he looked upon as a dangerous spy, to the Khalifa Abdullahi. This was in 1886. Neufeld was condemned to death, and was taken to the place of execution. He behaved there so courageously, asking to be executed like a Mohammedan, instead of suffering death by hanging, that the Khalifa was struck and respited him under the gallows. He was taken to the general prison, with heavy chains on his hands and feet, and treated altogether in a most abominable manner. He was kept alive by the women, who took pity on him and fed him, as they had done before him to Slatin. Then an endeavor was made to utilize his knowledge. He knew nothing about founding cannon, but he managed to manufacture powder, and he was also ordered to invent a machine for coining money. Owing to the escape of Father Ohrwalder and, later, of Slatin Pasha, his position became worse. He was again manacled and threatened with having his arms and feet hacked off if he should attempt to escape. There were many efforts to liberate him. The Austrian Catholic mission, induced by Father Ohrwalder, Slatin Pasha, the British Government, the German, and more especially the Austrian, representatives at Cairo, all endeavored to further the escape of Neufeld. He frequently received money, but he refused to escape, as he would not accept liberty without his wife—an Abyssinian slave presented to him by the Khalifa—and the two children whom she had borne him. The latter would have been exposed to fearful tortures, and thus Neufeld chose to remain a prisoner. He was active subsequently also as an artist, and as he could draw well he was ordered to decorate the mausoleum of the Mahdi, and this pleased the women of the Khalifa so much that they petitioned the latter for his liberation. It is also said that he has written Arabic books and illustrated them. The latter part of his twelve years' detention appears to have been less onerous, as after the escape of Slatin he had to be interpreter to the Khalifa and translator of European newspapers which the ruler of the Soudan received regularly. It is to the credit of the Khalifa Abdullahi that not one of the Christian prisoners received a hurt on the approach of the Anglo-Egyptian forces. It is expected that a narrative of his experience in the Soudan will be shortly published by Dr. Neufeld."

Natural Selection and Fortuitous Variation.—The three principal objections urged against Darwin's theory of natural selection were stated by Prof. W. F. R. Weldon, in his presidential address to the Section of Zoology and Physiology of the British Association, as being that the species of animals we know fall into orderly series for the selection of which purely fortuitous variations can not be supposed to afford opportunity; that minute structural variations can not be supposed to affect the death-rate so much as the theory requires they should, while many of the characters by which species are distinguished appear to us so small and useless that they can not be supposed to affect the chance of survival at all; and that the process of evolution by natural selection is so extremely slow that the time required for its operation is longer than the extreme limit of time given by estimates of the age of the earth. The first of these objections the speaker alleged to be due to a misunderstanding of words; we regard as fortuitous what we do not understand; and he proceeded to explain how what we call chance may be shown, especially by a method developed by Professor Pearson, to be a real and important factor. To the other two objections Professor Weldon opposed the results of observations of his own and of Mr. Herbert Thompson on the small shore crabs (Carcinus moenas) at Plymouth Beach. "In these crabs small changes in the size of the frontal breadth do, under certain circumstances, affect the death-rate; and the mean frontal breadth among this race of crabs is, in fact, changing at a rate sufficiently rapid for all the requirements of a theory of evolution." In conclusion, he said: "I hope I have convinced you that the law of chance enables one to express easily and simply the frequency of variations among animals, and I hope I have convinced you that the action of natural selection upon such fortuitous variations can be experimentally measured, at least in the only case in which any one has attempted to measure it. I hope I have convinced you that the process of evolution is sometimes so rapid that it can be observed in the space of a very few years." The whole difficulty of natural selection, he added, is a quantitative difficulty; and he insisted upon the need of observations and measurements of the rates of variation.

The Interior of Canada.—The country between Lake St. John and James Bay is under survey by the Department of Colonization and Mines of Quebec, in furtherance of a scheme for a transcontinental railroad to tap the Hudson Bay country and Lake Winnipeg. As to the commercial advantages of a railway center established at the head of James Bay or at the limit of tide water on the Nottaway River, Mr. O'Sullivan, the surveyor, shows that the shore line of Hudson and James Bay, following the east coast from the mouth of the Nottaway to the southern entrance to Hudson Strait, measures, in a line running due north, eight hundred miles, or about the same distance as the former point is north of the city of Washington; and the western shore line, measured in the same way to Rowe's Welcome, is about sixteen hundred miles, while the area inclosed amounts to more than three hundred and fifty thousand square miles. While Hudson Strait is blocked with ice during nine months of the year, the bay itself is navigable from June till November, and James Bay is generally open early in May. All the large rivers—the Albany, Moose, Hannah, Nottaway, Rupert, Main, and Big Rivers—converge along these shores, and the forest wealth of the thousands of miles drained by these and lesser rivers can be concentrated at the mouth of the Nottaway or Rupert. The land along the line from Lake St. John is good dry land fit for settlement. The Nottaway at the crossing point is fourteen hundred and fifty feet wide, and admits bridge spans of five hundred feet. Thence, a direct line to Norway House, at the foot of Lake Winnipeg, would pass through the gypsum beds on Moose River, and give access to a vast area of rich agricultural land in the north part of the province of Quebec. The straight line continued would strike about the forks of the Peace and Smoky Rivers, near the center of the northwest wheat-growing region, and thence follow the valleys of the Peace and Skeene Rivers to the Pacific Ocean, crossing the Rocky Mountains at a point where the summit is two thousand feet lower than that of the Canadian Pacific Railway. As to the resources of this northwestern country, there are, according to a Dominion official report, an area of six hundred and fifty-six thousand square miles along the Mackenzie River suitable for the growth of potatoes, four hundred and seven thousand suitable for barley, and three hundred and sixteen thousand for wheat, with a pastoral area of eight hundred and sixty thousand square miles, two hundred and seventy-four thousand miles of which may be regarded as arable land. "The difference in latitude makes no corresponding difference in the climate. Flowers bloom as early in the spring and as late in autumn at Great Slave Lake as at Winnipeg or St. Paul and Minneapolis. The prevailing southwest or Chinook winds render the climate along the Peace and Liard Rivers as mild and salubrious as that of western Ontario. Wheat ripens along the Mackenzie River under the Arctic Circle, a thousand miles farther north than Rupert House."