Popular Science Monthly/Volume 36/December 1889/Popular Miscellany


The Name Silurian in Geology.—We have received from Prof. Dana the following note in explanation of a change in geological nomenclature recently proposed by him: "The names for the grander divisions of the Palæozoic series below the Devonian used in most of the recently published works on geology are Cambrian, Lower Silurian, and Upper Silurian. Cambrian was proposed by Sedgwick, and Silurian by Murchison, and both names are derived from the names of ancient tribes of Wales. In 1879 Dr. Lapworth proposed to substitute the term Ordovician. a term of like origin, for the Lower Silurian, and its adoption is under discussion. Although not seeing any need of further change, I urged, in my paper before the American Geological Society at Toronto, that the name Silurian, if it is to be restricted, should be used for the Lower Silurian rather than the Upper, on the ground that it was more just to Murchison and better for the science. I further added that for a new name for the Upper Silurian, rather than go again to Wales for one, we should consider the claims of Bohemia, the land where Barrande carried forward his great work on the Silurian and associated rocks, or to the region of New York and Canada, made famous geologically by the Palæozoic labors of Hall, Billings, and others. I stated that the French geologist, De Lapparent, had already used the name Bohemian for the Upper Silurian; and I then remarked that the lower portion of the Upper Silurian was called the Ontario Division in the Reports of 1842 and 1846 of the New York geologists, Profs. Mather and Emmons, and that this suggested the use of the name Ontarian. This would make the names for the three grand divisions referred to the Cambrian, Silurian, and Ontarian.

"James D. Dana."

History in High and Preparatory Schools.—Two opposite demands, according to Mrs. Mary Sheldon Barnes, have to be met in teaching history in the high school; one for the generalities which are the commonplaces of every scholar, the other for fresh and independent study of historic detail from historic sources. As a solution of the difficulty thus raised, the author proposes teaching the general truth through the special fact, and making each pupil judge the special fact for itself in its general aspects. The first step in this direction should be to give the student a little collection of historic data, and extracts from contemporary sources, together with a few questions within his power to answer from these materials. "Then let him go by himself, like Agassiz's famous student with the fish, to see what he can see." The prominent characteristics of the method employed by Prof. I. B. Burgess, of Newport, R. I., for teaching classical history preparatory to college, are, almost exclusive attention to the facts which are essential to the comprehension of Greek and Roman life and its development; the study of primitive facts, such as maps, pictures of Greek and Roman works; speeches and writings of Greeks and Romans; and the use of questions about these facts, which require not the simple repetition of them, but the gathering and comparison of different facts, and the drawing of inferences from them by the pupil himself.

An Unsettled Part of Minnesota.—The report of the Geological and Natural History Survey of Minnesota for 1887 consists most largely of local details, of interest chiefly to the specialist. The work was prosecuted by three parties, two of them operating in the region of the original Huronian and the iron-bearing rocks of northern Michigan and Wisconsin, and the third in the region of Rainy Lake, while briefer surveys were made in other regions. Prof. N. H. Winchell's examination of the original Huronian leads to some important results which have a direct bearing on the classification of the rocks of Minnesota and of the Northwest. Prof. Alexander Winchell describes the Huronian region as traversed from east to west by a low, interrupted swell, called the Giant's Range, and by another series of still higher reliefs called the Mesabi Range—which must, however, be distinguished from another Mesabi Range—but without conspicuous features of mountain relief. As a rule, the surface is rugged and uncultivable. Between Fall Lake and Grand Portage, and north of Grand Marais, the region is "a literal wilderness without inhabitant, without mails, without roads, and with only an occasional party of Indians or explorers, following the ancient and overgrown trails of two centuries ago." Fires have denuded the region of its primitive forests; but the older burnings are becoming overgrown with thickets of aspen, white paper birch, cherry, etc. A few remnants of the original forest are occasionally found; and various shrubs and low herbs occur. Many small tracts of deep and productive soil intervene between the almost universal rocky or thinly covered exposures. The summer climate was agreeable, with sunny days as the rule during two seasons. No experience was had of the winter climate. The character of the country covered by Mr. H. V. Winchell's Rainy Lake survey varies greatly in different regions. In the vicinity of Rainy and the neighboring lakes, it is very rocky, while west of these lakes the surface consists of drift deposits, and the underlying rock appears only at rapids and waterfalls in the streams and a few places in the midst of the forest. The region within the limits of the glacial lake Agassiz is now covered with a fine growth of timber, both hard and soft wood, and is excellent farming land.

Old Cyclopædias.—The most extensive, and one of the oldest of cyclopædias is the Chinese work, the name of which may be translated as the "Thesaurus of Writings Ancient and Modern," compiled under the scholarly Emperor Kang Hi, which was printed toward the close of the last century. It was the fruit of forty years of labor, and filled 5,020 volumes; but this by no means implies that it was as large as a European book of that number of volumes would be. Pliny's "Natural History" may be regarded as the oldest European encyclopaedia. The "Speculum Majus" of Vincent de Beauvais, in the thirteenth century, was divided into 10,000 chapters, several of which were subdivided alphabetically. About a hundred years later came the "De Proprietatibus Rerum" of the English Franciscan Bartholomew de Glanville, which was translated into the English of the day. Johann Alsted's "Encyclopædia" (1630) was one of the first works that bore the name. The anonymous "Universal Historical Geographical, Chronological, and Classical Dictionary" (1703), a nearly forgotten work, is said to be "full, concise, lively, and, all things considered, wonderfully accurate," but some very funny statements made in it are pointed out. In the next year was published Dr. Harris's "Lexicon Technicum, or an Universal Dictionary of Arts and Sciences," which has been given the credit, that of right belongs to the preceding work, of being the first alphabetical encyclopaedia written in English. Next to these works follow the generation of cyclopaedias which are still known among us, beginning with Ephraim Chambers's Cyclopaedia (1728) and D'Alembert and Diderot's great work, and coming down to the new edition of the "Britannica," Stephen's "Dictionary of National Biography," and Appletons' "American Cyclopædia" and their "Cyclopædia of American Biography."

The Ice-Cap of Greenland. Dr. Frithiof Nansen showed, in the British Association, in opposition to Nordenskiöld's opinion, that the part of Greenland which his expedition had traversed is covered with a shell-shaped mantle of ice and snow, under which mountains, as well as valleys, have quite disappeared, and where the configuration of the land and mountains can not be traced. The ice covering rises rather regularly but rapidly from the east coast to a height of nine or ten thousand feet, is rather flat and even in the middle, and falls off again regularly toward the west coast. There must be mountains and valleys in the interior of Greenland as well as on the coast. It is already known that there are on the coasts deep fiords and lofty mountains very like those of western Norway, and that they have in some places just the same wild and prominent character. If we entertain the opinion that these fiords were excavated by the ice, we must also conclude that the same ice has been able to excavate valleys and form mountains in the interior of the continent. We have no right, therefore, to seek the reason of the shield-like shape of the ice in the configuration of the land underneath its surface. It must have a shape of its own, which was given, not by the land, but by the meteorological circumstances. Nobody could deny that the ice might in some places have an enormous thickness, as it filled the valleys and covered up all the mountains. The thickness must be regulated by the quantity of snow falling, and this is largest toward the coast, gradually diminishing toward the interior. Hence the thickness of the ice would be greatest on both sides toward the coast, just as has been observed. The surface of the snow-field in the interior is even and as if polished, resembling the undisturbed surface of a frozen sea, the long but not high billows of which, rolling from east to west, are not easily distinguishable to the eye. The principal factor in giving the surface this shape is the wind. A careful observation of a snow and ice covering like that of Greenland is of great importance for the theory of the formation of valleys and fiords. It seems that the more we study Greenland, its coasts, and its inland ice, the more convinced we must feel of the power of the ice to perform this work.

The Bruce Photographic Telescope.—The Astronomical Observatory of Harvard College has received from Miss C. W. Bruce a gift of fifty thousand dollars for the construction of a photographic telescope such as the director had described in his circular of November 28, 1888, as desirable. The instrument will have an objective of about twenty-four inches aperture, and a focal length of about eleven feet. It will differ from other large telescopes in the construction of its object-glass, which will be a compound lens of the form used by photographers and known as the portrait lens. The focal length of such a lens is very small compared with its diameter, and much fainter stars can be photographed in consequence. The advantage is even greater in photographing nebulæ or other faint surfaces. Moreover, this form of lens will enable each photographic plate to cover an area several times as great as that which is covered by an instrument of the usual form. The time required to photograph the entire sky is reduced in the same proportion. A telescope of the proposed form, having an aperture of eight inches, has been in constant use in Cambridge for the last four years, and is now in Peru photographing the southern stars. It has proved useful for a great variety of researches. Stars have been photographed with it too faint to be visible in the fifteen-inch refractor of the observatory. Its short focal length enables it to photograph as faint stars as any which can be taken with an excellent photographic telescope having an aperture of thirteen inches. The eight-inch telescope will photograph stars about two magnitudes fainter than can be taken with a similar instrument having an aperture of four inches. A corresponding advantage is expected from the increase of the aperture to twenty-four inches. Other advantages to be anticipated from the use of such an instrument will arise from the opportunities which the photographs will give for continuous and detailed study. With them work can be done at any place and any time, and, by multiplying copies, by any number of observers. And with them more could be added by a single lens to our knowledge of the stars than could be obtained by any number of telescopes of the usual kind. Prof. Pickering is seeking the best possible location at which to mount the instrument. Owing to the difficulty in maintaining regular observations in the Eastern States that arise from the prevalence of cloudiness, he suggests one of the mountains of southern California as likely to offer the most favorable climatic conditions attainable.

What it takes to play a Piece of Music.—Science, says Sir James Paget, will supply the natural man with wonders uncounted. The author had once heard Mile. Janotha play a presto by Mendelssohn. She played 5,595 notes in four minutes and three seconds. Every one of these notes involved certain movements of a finger, at least two, and many of them involved an additional movement laterally as well as those up and down. They also involved repeated movements of the wrists, elbows, and arms, altogether probably not less than one movement for each note. Therefore there were three distinct movements for each note. As there were twenty-four notes per second, and each of these notes involved three distinct musical movements, that amounted to seventy-two movements in each second. Moreover, each of those notes was determined by the will to a chosen place, with a certain force, at a certain time, and with a certain duration. Therefore there were four distinct qualities in each of the seventy-two movements in each second. Such were the transmissions outward. And all those were conditional on consciousness of the position of each hand and each finger before it was moved, and, while moving it, of the sound and the force of each touch. Therefore there were three conscious sensations for every note. There were seventy-two transmissions per second, one hundred and forty-four to and fro, and those with constant change of quality. And then, added to that, all the time the memory was remembering each note in its due time and place, and was exercised in the comparison of it with others that came before. So that it would be fair to say that there were not less than two hundred transmissions of nerve force to and from the brain outward and inward every second, and during the whole of that time judgment was being exercised as to whether the music was bring played better or worse than before, and the mind was conscious of some of the emotions which the music was intended to inspire.

Ancient Chaldean and Modern Measures.—According to Prof. Harkness, in his presidential address to the Philosophical Society of Washington, the ancient Chaldeans used, primarily, the decimal system of notation, and also the duodecimal in the division of the year and of the day into hours, and the sexagesimal in the division of the circle and of the hour and minute. The last two systems were also applied to weights and measures, and impressed upon them by the scientific authority of those ancient sages. "Now observe," says the author, "how the scientific thought of to-day repeats the scientific thought of four thousand years ago. These old Chaldeans took from the human body what they regarded as a suitable unit of length, and for their unit of mass they adopted a cube of water bearing simple relations to their unit of length. Four thousand years later, when these simple relations had been forgotten and impaired, some of the most eminent scientists of the last century again undertook the task of constructing a system of weights and measures. With them the duodecimal and sexagesimal systems were Out of favor, while the decimal system was highly fashionable, and for that reason they subdivided their units decimally; but they reverted to the old Chaldean device for obtaining simple relations between their units of length and mass, and to that fact alone the French metric system owes its survival. Every one now knows that the metre is not the ten-millionth part of a quadrant of the earth's meridian, and in mathematical physics, where the numbers are so complicated that they can only be dealt with by the aid of logarithms, and the constant π, an utterly irrational quantity, crops up in almost every integral, mere decimal subdivision of the units counts for very little. But in some departments of science, as, for example, chemistry, a simple relation between the unit of length (which determines volume), the unit of mass, and the unit of specific gravity, is of prime importance; and wherever that is the case the metric system will be used. To engineers such relations are of small moment, and, consequently, among English-speaking engineers, the metric system is making no progress, while, on the other hand, the chemists have eagerly adopted it. As the English yard and pound are the direct descendants of the Chaldean-Babylonian natural cubit and mina, it is not surprising that the yard should be only 0·48 of an inch shorter than the double cubit, and the avoirdupois pound only 665 grains lighter than the Babylonian commercial mina; but, considering the origin of the metric system, it is rather curious that the metre is only 1·97 inches shorter than the Chaldean double royal cubit, and the kilogramme only 102 grains heavier than the Babylonian royal mina. Thus, without much exaggeration, we may regard the present English and French fundamental units of length and mass as representing respectively the commercial and royal units of length and mass of the Chaldeans of four thousand years ago."

Mount Roraima.—Mount Roraima, that sharply perpendicular elevation in Guiana which so long defied attempts to reach its summit, has been ascended twice since it was first conquered by Mr. Im Thurn in 1884—by Mr. F. Dressel and Mr. Cromer, in October and November, 1886. While Mr. Im Thurn's ascent took place at the beginning of the rainy season, Mr. Dressel's was in the dry season, and their respective observations were marked by corresponding differences. Mr. Im Thurn had observed no animal life while he was upon the mountain; Mr. Dressel saw a few butterflies, all of a dark-brown and nearly black color. In the shallow basins a few specimens of a small black toad with a yellow spot on the throat were found. A third animal form was noticed in the moist earth attached to some plants which had been pulled up—a milliped. The fantastic shapes into which the sandstones have been formed, and the calmness of the scene, affected Mr. Dressel as they had Mr. Im Thurn.

Experience and Training in Mechanical Work.—To be a good mechanic, said Sir Benjamin Browne, at the recent meeting of the British Association, long training is necessary; and, above all, ability to distinguish good work from inferior work. A regular course of progress from one branch to another should be carefully followed, so as to teach every class of work up to the most difficult. In this the real interest of the employer is the same as that of the lad, viz., to learn every step thoroughly, and then pass on to something more difficult. The author contended that a long training in a manufactory is absolutely necessary, and this should be supplemented by theoretical and technical instruction. It would probably be a great gain to give a lad six or eight months of theoretical teaching after he is out of his apprenticeship. The old-fashioned system of apprenticeship, not much shortened, and with very slight modifications, is the only reliable method for either employer or mechanic to learn his business; but, as work has become more scientific and elaborate, it is necessary for any young man who wishes to excel to have a good theoretical and technical training in addition to his factory experience.

How Stone Implements were made.—Mr. Gerard Fowke, of Sidney, Ohio, has been studying the manner in which primitive man made his stone implements. Although the subject is one on which absolute knowledge can never be obtained, he has been able to reach some definite conclusions on it. Some of the material was obtained from extensive quarries in Coshocton County, and between Newark and Zanesville, Ohio, where the hills are seamed for miles with the trenches and pits left by the ancient diggers. To get the flint, the overlying stratum of earth, nine or ten feet thick, had to be removed, with wooden tools. The rock was then cracked by building a fire, and probably pouring water upon it, the process being repeated till the limestone was reached and a hole made large enough to work in. Other cracks were made by building a fire at the lower part of the ledge, and the split rock was detached. This work was sometimes carried on for several hundred yards. The stones were reduced to blocks of suitable size by stone hammers weighing, perhaps, two hundred pounds, and the shaping was carried on with hammers running, according to its stage and the quality of work desired, down to two ounces in weight. The finished object was smoothed and sharpened by rubbing it with sandstones. If a hole was wanted, it was drilled with a stick, cane-stem, piece of bone or horn, flint, or piece of sandstone, which was revolved in the hands, or twisted back and forth with the bowstring. This was not a speedy process. Dr. Rau worked at it experimentally for two years, and left his first hole not bored through. Yet some of the Amazon tribes spend the lifetimes of two men in drilling, with the flexible shoot of a wild plantain and sand and water, the bores of their tubes of rock crystal. Handles were fitted on in a rude way and secured by wrapping with sinew, which shrunk and bound them tightly; or, with the aid of gum. The fashioning of arrow-heads was a very delicate and curious work, requiring skillful manipulation, and was performed with stone hammers or chisel-points of deer-horn or wood.

Bellite.—The new explosive, bellite, was recently subjected in England to some very satisfactory tests of its safety and power. Letting a great weight fall upon cartridges composed of it, they were simply crushed into a hard mass. But when the crushed cartridges were afterward detonated by means of a fulminate, immense energy was developed. Again, when placed in the fire of a smith's forge, it was volatilized. The effect of exploding a three-ounce cartridge on the lid of a case containing bellite was simply to pulverize the wooden case and scatter the contents. Comparative experiments showed that, when bellite was confined, the energy developed on detonation was equal to that of dynamite; but that when unconfined, bellite apparently did less work. In mine-blasting bellite was proved capable of doing the work of three or four times its weight of gunpowder, without the fumes that rise when dynamite or gunpowder is used.

Distribution of Rotifera.—Of the little animals classified as Rotiferæ, the most species have been found in Great Britain—not certainly because they are more abundant or varied in England than elsewhere, but because they have been more industriously looked for, and more found there. In late years, two and a half times as many species have been added to the British lists as to those of all other countries put together. There are curiosities in the distribution of these animals. Twenty-four out of the recorded species in Australia are also British; and of the remaining species, one has a habitat in the United States. The same phenomena occur, though on a reduced scale, in the United States, Jamaica, and Ceylon. The question arises, How could these minute creatures, which are inhabitants of lakes, ponds, ditches, and sea-shore pools, contrive to spread themselves over the whole earth? A species which is known only in a small duck-pond in England has also been found at Sydney. Another species has been found almost simultaneously at Sydney and in Ontario. These creatures, "to whom a yard of sea-water is as impassable a barrier as a thousand miles of ocean," could only have reached distant countries in the egg; this they do by the hardy ephippial egg. These eggs fall to the bottom of the water in shallow pools, or are attached to the confervoid growth on the stones. The pool dries up, is swept by the winds, and the eggs are lifted up and carried away. There is hardly any limit to the distances to which they may be thus taken and yet keep vital. Then, as Dr. C. T. Hudson shows in his paper on this subject, "the eggs, of course, must often fall on unsuitable places, and be carried past suitable ones, and this accounts for the capricious appearance of Rotifera in some well-watched ponds, and for the frequent disappointment of the naturalists who visit such spots. To this aërial carriage of the eggs is also due the perplexing fact that when any rare Rotifera is found in one spot, it is frequently found at the same time in closely neighboring ponds and ditches, even in such an unlikely hole as the print of a cow's foot filled with rain, but not at all in more promising place, at some distance off." They may also be distributed by water-birds and dogs. The animals themselves are very hardy against heat and dryness. The Philadinadæ, when time is given them to don their protective coats, oan bear a heat gradually advancing to 200° Fahr., or a fifty days' exposure to a dryness produced over sulphuric acid in the receiver of an air-pump.

The City of the Cat-Goddess.—M. Edouard Naville recently gave before the Victoria Institute an account of his important discoveries at Bubastis, one of the ancient great cities of the Delta of Egypt, and the principal seat of the worship of the cat-goddess, Pasht. The speaker said, at the beginning of his lecture, that it was remarkable that while one of the latest writers on the East had referred to the failure of the prophecies of Ezekiel regarding the cities of Egypt, he had himself found in the same prophecies the light by which he was guided in his search. Bubastis was found to have been a city of much more historical importance than had generally been supposed, the recovered monuments bearing dates all the way down from the fourth (or Pyramid-builders') to the thirtieth, or last Egyptian, dynasty. The most conspicuous relics were of the fourth, sixth, twelfth, shepherds', nineteenth, and twenty-second dynasties. Some very interesting relics of the shepherd-kings, hitherto rare except at Tanis, were found; and from the beauty of their statues, and other evidences, the author concludes that they must have been a highly cultivated people, and have come probably from Mesopotamia. Dr. Virchow considered that their monuments represented Turanians, and Prof. Flower that they represented people of a Turanian or Mongolian type. But that did not mean that the population itself was Turanian. Their worship and language were of a Shemitic type, but the statues of their kings showed that they were not Shemites. M. Naville remarked: "It was then what it still is now; and I believe that the conquest of Egypt by the Hyksos is not unlike what would happen at the present day if the population of Mesopotamia overran the valley of the Nile: you would have masses, in great majority of Shemitic race, speaking a Shemitic language, and having a Shemitic religion, but under the command of Turks, who are not Shemites, but Turanians." M. Naville regards the successive discoveries that have been made in the Delta as making the Bible-story more comprehensible in some points, and as showing that the distances were much shorter than was generally thought. "I consider it important, for instance, to have established that Bubastis was a very large city, and a favorite resort of the king and his family. It is quite possible that, at the time when the events preceding the Exodus took place, the king was at Bubastis, and not at Tanis, as has been generally believed."

Composition of London Fogs.—Studies of London fogs by various observers show that during the winter the air of the metropolis has an unusually large amount of carbonic acid in it. Thus, Dr. W. J. Russell found on one day, a few years ago, that it contained more than three and a half times the average amount. This is derived, to a large extent, from respiration, and more from coal-burning; and "it is almost indisputable that the latter produces the well-known black fogs and yellow fogs." The relative thickness and density of the air of different parts of London have been investigated by Mr. W. H. Raffles, who took a station on Primrose Hill and observed the visibility, on different days, of prominent objects at known distances in different directions. These observations showed plainly that the amount of fog was largely governed by the density of the population and the frequency of factories. A similar conclusion is drawn from the number of hours in the daytime on which artificial light was used. Homerton had twice as many hours of darkness as any other district represented in the tables, and it has a very large number of factories in its neighborhood. Of other towns in which the inquiry was pursued, Leeds suffered most from darkness, probably for the same reason; while Manchester is said to have been unusually free of late years from dark fogs, probably because many mills have moved out. The ordinary white fog has also been reduced by the draining of morass lands near the city. A conception of the cost of London fogs may be gained from the fact that during nine days of fog in November, 1887, the public paid a single one of the several companies four hundred and ninety pounds, or twenty-four hundred and fifty dollars, an hour for artificial light.

Geological History of Yellowstone Park.—The geological history of Yellowstone National Park has been traced by Mr. Arnold Hague in an address before the American Institute of Mining Engineers. Throughout Tertiary time the history was characterized by great volcanic activity. Within very recent times there is no evidence of any considerable outburst; indeed, the region may be considered long since extinct. The volcanic rocks present a wide range in chemical and mineral composition and physical structure, but may all be classed in the groups, following one another in the order named—andesites, rhyolites, and basalts. Since the close of the Ice period no geological events of any moment have brought about any changes in the physical history of the region other than those produced by the direct action of steam and thermal waters. Indications of fresh lava-flows within historical times are wholly wanting. All our observations point in one direction, and lead to the theory that the cause of the high temperature of the waters of the geysers and hot springs must be found in the rocks below, and that the origin of the heat is in some way associated with the source of volcanic agency. But it does not follow that the waters themselves are derived from any deep-seated source; on the contrary, investigation tends to show that the waters brought up by the springs are mainly surface-waters which have percolated downward a sufficient distance to be heated by large volumes of steam ascending through fissures and vents from much greater depths. The existence of such currents of steam and hot water is attested by the decompositions they have effected upon the rocks, which "have proceeded on a most gigantic scale"; and they have left an indelible impression upon the surface of the country. The study of the age of the present geysers by observation of the rate of deposit of sinter indicates a great antiquity for them—over twenty-five thousand years for "Old Faithful." Our accurate knowledge of them only began in 1871. The number of geysers, hot springs, mud-pots, and paint-pots scattered over the park exceeds thirty-five hundred, and the addition of the fumaroles and solfataras would make the whole number of actual vents double that.

Mound-Builders and Indians.—"Some Popular Errors in regard to Mound-Builders and Indians" are reviewed by Mr. Gerard Fowke, in the "Ohio Archæological and Historical Quarterly." The high civilization ascribed to the mound-builders is denied, because they have left no evidence that they could use stone-dressing tools, could carry earth only in baskets or skins, and have left no indications of having possessed a written language or domestic animals, etc. Against the assumption that they possessed a great population, it is shown that while the construction of all their works in Ohio did not require an amount of labor equal to that used in the excavation of certain modern works, there is nothing in the way of their having had an indefinite time in which to perform it. While "there is sufficient accuracy in some cases to make one wonder that the builders could have done as well as they did, no evidence appears of any 'calculation' beyond the mere sighting and measuring possible to any one." The supposed evidences of the great antiquity of the mounds and of the extensive commerce of the builders are assumed to be insufficient or fallacious; minor errors, concerning the distance from which the earth used in building the mounds had to be brought, concerning the size of the builders, the soundness and other peculiarities of their teeth, and the supposed artistic excellence of their work, are corrected; and the questions whether there is anything in their work that the Indians could not have executed, and whether the Indians had knowledge of them, are taken up. Traditions exist among the Indians of Michigan and Wisconsin of tribes who built mounds, and of definite occasions when mounds were built. A certain tribe were called by the Sioux Ground-House Indians, because they lived in houses covered with earth. The chronicles of De Soto's expedition describe the houses of the Cherokees as being built upon mounds, and the French give a similar description of the house of the king of the Natchez. Certain earthworks in western New York, Ohio, and Pennsylvania are conceded to have been built by the Iroquois and adjacent tribes. The Indians of the Ohio Valley may have been ignorant of the subject, because they were a comparatively recent arrival. It is objected that the Indians could not have built the mounds, because the builders must have been a settled and agricultural people, while the Indians live by hunting and fishing. But it is a historical fact that, before they were disturbed by the whites, the Indians also were agriculturists, raised good crops, and stored their grain, so that they were able to supply the expeditions that came among them. We can not judge of what they were from what they are, after having been ruined by their contests with the whites and their vices. The race that produced a Logan, a Corn Planter, a Red Jacket, a Tecumseh, and other men of like genius, might also have developed men competent to construct all the works that now puzzle us. Some of Mr. Fowke's assertions are traversed and shown to be erroneous in the "American Antiquarian," which, while it admits that the Indians built mounds, holds that there were other and more extensive mound-builders before them.

Experiments in Germination.—A series of testings of the influences of certain conditions on the sprouting of seeds, described in a bulletin of the experiment station at Cornell University, indicates that variations of temperature are an important factor in the matter, and that a constant temperature gives quicker results than an ordinarily variable one of which that is the mean. The mean employed in most of the experiments was 74°; but there is probably a tolerably well-defined best temperature for each species of plant, the limit of which is not closely determined for most garden seeds. Soaking the seeds does not appear to influence the total amount of sprouting; nor does it seem to hasten the sprouting, if the planting-time is reckoned from the moment of putting the seeds to soak; it only shortens the time the seeds have afterward to remain in the soil. The character of the soil may influence the results. Light, when it has any influence and it has great influence with some species—has a retarding effect. The weight of the seed is often a tolerably accurate measure of its viability. As a rule, heavy seeds germinate better than light ones of the same sample. When variability was perceived with reference to color, the stronger sproutings usually occurred in the darker-colored seeds. The latitude in which seeds are grown may determine their behavior in germination—northern-grown seeds seeming to germinate more quickly than southern-grown. More than one test is needed to be decisive respecting any sample of seeds. There appear, from the testings reported, to be no pernicious adulteration of garden seeds in this country, and no hurtful impurities.

Tapioca.—The manihot, or tapioca plant, was originally a native of tropical South America, but is now largely cultivated throughout all tropical countries. It is a small, shrubby plant, growing from four to eight feet high; and becomes suitable for use in from sixteen to eighteen months after the young plants are established. Besides the well-known wholesome food, the root abounds in a peculiar poisonous juice, which is said to be analogous to hydrocyanic acid; but this substance being volatile and easily destroyed by fermentation, no difficulty is met in procuring the food-product free from it. The pulp obtained from the roots is washed in cold water, after which, upon resting, the starch subsides. The water is then drawn off and the starch is heated, when pearl tapioca is obtained. In preparing the cassava meal, the roots having been prepared, are baked on an iron plate. Thus prepared, the meal swells considerably in water or broth, and is called cerraque. If, instead of drying the grated pulp, it is spread upon a hot iron plate, the starch and mucilage, by mixing together, consolidate the pulp and form a biscuit, called cassava bread, which is a very important and nutritious food. The resultant of the mastication of these cakes, upon fermentation, produces an agreeable but intoxicating drink.

The Island of Paros and its Marbles.—The Island of Paros, according to Mr. R. Swan's description in the British Association, is eleven miles long and eight miles broad at its widest part, with a mountainous interior rising to a height of twenty-five hundred and thirty feet, and a broad belt of nearly level land round the coast. The southern part of the island consists chiefly of crystalline limestone, of undefined age but probably Cretaceous. The finest statuary marble, or lychnitis, varies from five to fifteen feet in thickness at the quarries of St. Minas, and occurs in a bed of coarse-grained white marble with bluish-black veins. The coarse marble becomes dark in color near the lychnitis, both above and below it, and thus the layer of statuary marble is distinctly marked off. The dark color is due to traces of binoxide of manganese and magnetic oxide of iron. The rocks are much disturbed and folded, and often clip at high angles. The ancients avoided the marble lying near the axis of elevation, which was of inferior quality to the other parts. A Greek company, formed a few years ago to work the quarries, attacked the rock here, where it could be got at least expense, and so discredited the marble in the market that it went down, after one hundred and sixty thousand pounds had been spent in getting the quarry ready. There is a good deal of excellent colored marble on the island, but, not having been used by the ancient Greeks, is not much known.

A Classification of Incendiaries.—Dr. J. A. Fowler, of Philadelphia, has made a classification of more than twenty different kinds of incendiaries, or motives to incendiarism. They are 1, the incendiary policyholder; 2, the incendiary for gain or advantage other than insurance; 3, the revengeful incendiary; 4, the discharged hand; 5, the malicious servant; 6, the rioter; V, the tramp; 8, the thief (for concealment of theft); 9, the thief (for opportunity for theft); 10, the murderer (for concealment of crime); 11, the incendiary for murder; 12, the mischievous small boy (or girl); 13, the contriver for incendiary reward; 14, the fire-bug, or fire conspirator (terrorizing by fire); 15, incendiarism from momentary rage; 16, the drunken incendiary; 17, incendiary firemen; 18, the don't-care bonfire-kindler; 19, the don't-care pyrotechnic exploder; 20, the don't-care manufacturer of unsafe kerosene, etc.; 21, the "pyromaniac." The last four can not be considered legal incendiaries, "but they bring the trespass so near the crime that, they can be admitted into the insurance catalogue of incendiaries as practically such."

The Condition of Deep-Sea Life.—It is suggested by Mr. A. R. Hunt, in "Nature," that the depth of the horizon above which deep-sea fish do not rise, is controlled rather by the matter of wave-motion than of the penetration of light. It is doubtful if sunlight ever penetrates to the depth of a hundred fathoms, which Günther has indicated as marking the beginning of deep-sea life; but that depth has been indicated by Mr. Hunt as the extreme depth to which wave-action reaches. This view is fortified by the fact that, though the deep-sea forms do not usually ascend above the hundred-fathom line, the shallow-water forms go far below it; and there is no reason why they should not do so; for, although a form unfitted to withstand wave-currents can not face them, there is nothing to prevent a flat fish, fully equipped as to this condition, from passing at will from the disturbed to the tranquil horizon, and returning.

The History of the Doctrine of Assassination.—The history of the doctrine of political assassination or tyrannicide has been elucidated by a writer in the "Edinburgh Review." It prevailed among the ancients, as is illustrated in the stories of Brutus and of Harmodius and Aristogiton. Its great apologists have been the Jesuits, but it is much older in its Christian form than the Jesuit order. At the beginning of the fifteenth century, not to go further back, a Franciscan friar, Jean Petit, who was Professor of Theology at Paris, undertook to justify the murder of the Duke of Orleans, on the plea that "it is lawful, by natural and divine law, for every subject to kill or cause to be killed a traitorous and disloyal tyrant." His teaching was denounced by Gerson and condemned by the Council of Constance. The decree of the council was, however, rejected by one author because it was not sanctioned by the Pope; while others sought to evade its force by making a distinction between a tyrant in titulo, or a usurper, and a tyrant in regimine, who is a lawful sovereign but has abused his trust. The decree could not, these writers alleged, apply to the tyrant in titulo, because a usurper has no subjects. Mariana, in his famous work "De Rege et Regis Institutione," published in 1599, defined as tyrants all sovereigns, legitimate or not, who forfeit their rights by governing for their own selfish interests, not for the good of their people; and held that such unjust rulers became the enemies of the human race, and might lawfully be slain by their subjects. He argued that the sovereign power is always dependent on popular consent, and that a tyrant is worse than a ferocious wild beast. When there existed a public assembly in the country, it should meet and pronounce sentence first, but, where no such resource was available, any person who had the courage might lawfully make himself the interpreter of the popular will. But the use of poison was forbidden by the common sense of mankind. The doctrine is, however, a most mischievous one, which is easily made to work both ways.

Evolution and Disease.—Dr. R. G. Eccles, in a paper on "Heredity and Disease," advises the application of the principles of evolution to pathological studies. "A vague, uncritical sort of belief in the transmission of disease tendencies," he says, "has obtained among general practitioners for a long time. Few have dared to allow themselves to speculate upon the possibility of this chain of tendencies stretching back into the world of animated nature below us. No one has a due conception of the vast magnitude of the possibilities involved in so daring a speculation. Is there any reason for believing that a large number of weaknesses and disease tendencies of the human family are part of this great system that makes us appear as if we had descended from quadrupeds? What harm can it do for us to work on this assumption for a while, and see whether or not it will prove as fruitful to the pathologist as it has been to the botanist, zoölogist, and physiologist?" In a similar vein Dr. Wesley Mills regards the various forms of disease as so many cases, by the deterioration of his higher faculties, of reversion toward the lower forms from which man is derived. Thus, the dying human subject sinks functionally lower and lower in the scale of animal life. In sleep it will be seen, if we consider the nervous system, that the parts peculiar to man, or most developed in man, are the ones that for the time being are as good as annihilated. Similar tendencies toward a sinking to equality with lower forms may be observed in hypnotism, somnambulism, and allied phenomena. It is seen, on a lower level, in hibernation, when certain normally very active animals return to a condition like that present in cold-blooded animals. In paralysis, the graver the affliction the lower in the scale must we seek to find an animal comparable to man in that condition. Views in harmony with those of Prof. Mills were published by Dr. Milner Fothergill.

The Office of Iron in the Blood.—Iron exists in the blood in the red corpuscles, and gives them color and the power of absorbing gases. The fact that peroxide of iron is one of the readiest absorbents of gases, and parts with them as readily on exposure in thin layers to the air, so that it can be used over and over again for that work, gives a clew to its special function in the red corpuscles of the blood. It enables them readily to absorb oxygen as they pass along the minute blood-vessels of the lungs, and to carry it to all parts of the body, where they part with it as it is demanded. It is supposed, also, to take up carbonic acid in exchange for the oxygen it yields up, and to convey to the lungs that portion of this substance which is expired. If this be its double function, it is one the importance of which can hardly be exaggerated; for it is, in effect, to be the vehicle to all parts of the organism of that which makes them vital, while it also removes the waste of their life, which would otherwise clog their activity. The chemical changes in the life of plants are effected by means of the iron which is contained in the chlorophyl by processes that differ in particulars, but are dependent on the same absorption principle of the peroxide. Thus "it is an interesting coincidence that iron should be the active agent in both animal and vegetable life for the assimilation of the air substances required for their existence; and that at the same time it should be intimately connected with the production of the distinctive color of the blood and of the foliage of plants."

Iron Railway-Ties.—Iron sleepers or cross-ties have been in use for many years on the railroads of India, and have proved as free from liability to accident as wooden ties. The East India Railroad has more than one thousand miles laid with them, and is adding to the length every year. It runs the fastest and heaviest trains on the peninsula, and has enjoyed an almost proverbial immunity from accidents. The "bowl sleeper" appears to be the standard type, although it was once condemned. It lies more steadily and is less liable to horizontal displacement than any wooden sleeper. It, however, makes the track too rigid, and is not suitable for high speed, and is likely to be discontinued again. A tie called the "D and O sleeper" gives a more elastic track, and is more conveniently packed than the hollow sleepers.