Popular Science Monthly/Volume 4/April 1874/Miscellany


Rumford's Discoveries in Thermodynamics. —In his sketch of the growth of the science of thermodynamics, Prof. P. G. Tait, of the University of Edinburgh, rates the services of Count Rumford second in importance to those of Davy, and does not apparently consider them comparable to those of Joule. Prof. R. H. Thurston, of the Stevens Institute of Technology, in a note relating to Rumford's determination of the mechanical equivalent of heat, points out the injustice of this proceeding, on the part of Prof. Tait, and says that we may claim for Rumford: 1. That he was the first to prove the immateriality of heat, and to indicate that it is a form of energy, publishing his conclusions a year before Davy; 2. That he first, and nearly a half-century before Joule, determined, with almost perfect accuracy, the mechanical equivalent of heat; 3. That he is entitled to the sole credit of the experimental discovery of the true nature of heat. Benjamin Thompson, of Concord, New Hampshire, commonly known as Count Rumford, should be accorded a nobler position and a higher distinction than he has yet been given by writers on thermodynamics."

Antiquity of Man..—R. H. Tiddeman publishes in Nature an interesting paper on the "Relation of Man to the Ice-sheet in the North of England," in which he describes, with some detail, the fossils found in Victoria Cave, in Yorkshire, now being explored by a committee, aided by the British Association. In this cave discoveries of a most interesting character have been made. In a bone-bed, beneath other deposits, were found bones, teeth, and other remains of extinct species of animals. Prof. Burke identified remains of the Elephas primigenius, rhinoceros, cave-bear, hyena, bison, and others, and among these remains was a human bone, a somewhat clumsy fibula (small bone of the leg). Of this Mr. Busk says: "The relic is human; there is no room for the slightest doubt on the subject." And this opinion is fully confirmed by Prof. James Flower, of the College of Surgeons.

The position of the locality in which this bone was found makes its discovery of great importance. It seems to carry back the period when man existed to glacial if not to preglacial times.

Trout from an Artesian Well.—In the Journal of Science and Art we find a note from Mr. A. W. Chase, giving the following curious information, which the author received from Mr. Bard, agent of the California Petroleum Company at San Buenaventura: Mr. Bard, wanting water to supply a newly-constructed wharf at Point Hueneme, southeast of San Buenaventura, commenced sinking an artesian well on the sea-beach, not five feet from high-water mark. At the depth of 143 feet a strong flow of water was obtained, which spouted forth to a height of 30 feet. It was controlled with a "gooseneck," and utilized. One day while the agent was absent, the men around the well noticed fish in the waste water. On his return, they called his attention to the fact, and, on examination, the well was found to be filled with young trout, thousands of them being thrown out at every jet. These trout were all of the same size (about two inches long), and perfectly developed. The first examination was made to see whether they had eyes. These were found perfect. Now, there is no stream nearer than the Santa Clara River, several miles distant. Could these fish, then, have come from its head-waters by some subterranean outlet? There are no trout in the lower portions of the stream. The temperature of the water is the same as that of the wells all around, viz., 64° Fahr., too warm, of course, for trout to live in it long.

Atkins Charcoal Filters.—The Atkins system of filtering water is spoken of in terms of high commendation in Iron, from which journal we take the following description of the system: The best and purest animal charcoal is ground and pulverized until it is brought into the finest possible state of comminution, and, thus prepared, it is mixed up with a definite proportion of Norway tar, and a compound of other combustible ingredients. The combined materials are then thoroughly amalgamated with liquid pitch, and the whole kneaded up into a homogeneous plastic mass, which admits of being moulded into slabs or blocks of any required dimensions and shape. These blocks having been allowed to dry and harden, are subsequently carbonized by being subjected to a process of incineration by heat; and, in this manner, all the combustible ingredients are burnt out of the block, leaving nothing behind but the animal charcoal in the form of a block of charcoal, permeated throughout by innumerable pores, admirably adapted for the mechanical infiltration of fluids, while subjecting them, in a minutely subdivided state, to the chemical absorptive and purifying action of the carbon itself.

These carbon-blocks are chiefly cast in cylindrical forms, so arranged that the percolation is from the external periphery inward, and the centre of the block is hollow, forming a tube whence the filtered water flows. In this way the bulk of the impurities is deposited on the outside of the block, whence it may be removed by washing with hot water, or by scraping. Such filters, singly or in numbers, are placed in the bottom of a cistern, the central pipes of efflux being all connected together, and with one outlet. Where a large filtering capacity is required, a different principle is adopted, viz., a series of carbon-plates. In this case the water, in its passage from the inlet to the outlet, is caused to pass through a number of frames, variously constructed, according to circumstances. Thus there may be, firstly, a frame, covered with fine wire gauze; then separate frames, paneled with carbon-plates, with or without the intervention of a bed of pure loose animal charcoal, filling up the spaces between them; and there may be also a double frame, containing a sheet of felt compressed between two perforated plates, made respectively of sheet-copper and zinc, which would exert a certain electrical action, and aid in the chemical action of precipitating impurities. The system may be used for filtering the water-supply of a town.

Apart from this hygienic use, these carbon-blocks may be employed for many industrial purposes. Experiments have shown them to be efficacious in removing deleterious gases, and other soluble substances held in solution in fluids. They are applied as filters for wines, oils, and syrups; and, above all, they merit attention as an adjunct to the feed-water apparatus of steam-boilers, inasmuch as efficient filtration affords the best, cheapest, and surest method for preventing incrustation in boilers.

Cremation.—An eccentric will, wherein the testator requested that his body might be consumed in a gas-retort, and thus made to contribute to the enlightenment instead of the poisoning of the world, has survived the long-forgotten subject of cremation. Without doubt, Mr. Trelawney's hideously-graphic description of the burning of the body of Shelley has greatly contributed to prejudice the public mind against the cleanest and best method of getting rid of the "mortal coil." But the ceremony at Spezzia was conducted in the most bungling fashion, and a want of scientific appliances contributed to the incompleteness, and, therefore, to the horror of a simple operation. A retort gets rid of the entire difficulty, and, both from a utilitarian, a scientific, a sanitary, and a poetic point of view, the mausoleum, decked with cinerary urns, possesses immense advantages over the damp and unwholesome graveyard, exhaling pestiferous odors, to which modern nations, for some inscrutable reason, are preposterously wedded.—Iron

Death of Dr. Forbes Winslow.—Dr. Winslow was born in London in 1810. He began his medical studies in New York; took the degree of M. D. at King's College, Aberdeen, and became a member of the Royal College of Surgeons, London, in 1835. His first published works appeared in 1831, since which time he has made numerous important contributions to the literature of medicine, chiefly in the department of nervous and mental diseases. His most valuable work in this line, "The Obscure Diseases of the Brain, and Disorders of the Mind," was published in 1860, and has since passed through several editions. He died in London, on March 4, 1874.

The Economy of Beer.—Prof. Max von Pettenkofer, the eminent Munich chemist, states that, to make a quart of good beer, there is required, at least, a pint of good barley, besides hops, etc. The product contains not a single trace of albumen, and only a very small percentage of alimentary principles: in short, it is only a condiment, not a food-stuff properly so called. The question now arises, Would it not be better to send this barley to the mill, and make of it a bread-stuff, instead of brewing from it a costly beverage, which contributes little or nothing to the system? Or, better still, Would it not be advisable to grow, in place of barley and hops, wheat and rye, either of which would give better bread than barley?

Prof. Pettenkofer holds that the need of mere condiments is no less imperative than the need of food-stuffs, properly so called. "Butter and cheese," says he, "are neither as good nor as complete foodstuffs as milk, and yet butter and cheese are made, and will continue to be made, even though it were possible to transport milk in good condition to considerable distances." The same is to be said of barley and beer. Prof. Pettenkofer observes that the consumption of beer is steadily increasing in spite of the advance in prices, and he is convinced that this state of things will continue, no matter what weight of argument may be brought against it. "Condiments of this kind," says he, "are often, no doubt, the occasion of real waste, but yet the majority of mankind can always, to their great profit, find, by observation and self-control, the proper amount of them to consume"

Sensation and Motion in Plants.—Treating of the vital phenomena which are common to plants and animals, the eminent French physiologist, Claude Bernard, observes that Linnæus's criterion of animality, viz., sensibility and mobility, is not in accord with facts. There are many plant-forms on the boundary between the animal and the vegetable worlds, for instance, the zoospores of the algæ, which have the power of motion. Then the antherozoids, particularly the œdogonium, studied by Pringsheim, manifest the faculty not only of motion in general, but even of motion toward a definite object—in other words, show all the appearances of voluntary movement. As instances of mobility in plants, the author further cites the movements of the stamina of the Berberis (barberry), the Drosera, the Dionæa muscipula (fly-catcher), and the oscillating sainfoin (Hedysarum gyrans).

Sensibility too is found in several plants. The Mimosa pudica (sensitive-plant) is the most prominent instance of this. This plant reacts against any irritation by folding up its leaves, which again are spread out soon after the exciting cause is removed. It is a curious circumstance that most of the agents which excite sensibility in animals have a like effect on the mimosa: thus it is affected by sudden shock, by burning, by the action of caustic, by electrical discharges, etc. Nay, the same agents, such as chloroform and ether, which deaden sensibility, or assuage pain in animals, destroy the mimosa's power of reaction. Vegetal anæsthesia is produced by the same means as animal anæsthesia.

There are other plants besides the Mimosa pudica which manifest this curious property of reacting against irritation, for instance, the leguminosæ of the genera Smithia, æschynomene, desmanthus, Robinia pseudacacia and the Oscalis sensitiva of India. From all this it follows that the power of movement and sensibility are functional properties which cannot strictly serve as a distinction between the vegetable and animal worlds.

Is Sex determined by Nutrition?—Mr. Thomas Meehan exhibited to the Philadelphia Academy of Natural Sciences specimens of the Juglans nigra (black walnut), with a view to showing that sex in plants is the result of the grade of nutrition, the highest grades of nutrition or vitality producing the female sex, and the lower grades the male. Examining a black-walnut tree at the flowering season, even the superficial observer will perceive three grades of growing buds. The largest buds make the most vigorous shoots. These seem to be wholly devoted to the increase of the woody system of the tree. Lower down the strong last-year shoots are buds not quite so large. These make shoots less vigorous than the other class, and bear female flowers on their apices. Below these are seen numerous small, weak buds, which either do not push into growth at all, or, when they do, bear simply the male catkins. As some naturalists hold that the feeble condition of these lower shoots is the result of their bearing male flowers, Mr. Meehan invited attention to the specimens themselves as conclusively proving the contrary. He was fully satisfied that any one, who would go out into the woods and fields for facts fresh from Nature, would see that there is not so great expenditure of vital force in the production of male flowers as there is in that of female flowers, and thus all he had advanced on this subject was fully sustained.

It will be remembered that, in our June number, we recounted the observations of Mrs. Mary Treat on the subject of controlling sex in butterflies, from which it appeared that butterfly-larvæ developed into male or female butterflies according as they were stinted in food, or liberally supplied with it. Besides the very interesting observations of Mr. Meehan, we have now further confirmation of Mrs. Treat's results in a paper communicated to the Philadelphia Academy by Mr. Gentry. The latter author, in the summer of 1871, had confined the larvæ of various species of moths, and neglected to supply them with food for four or five days. These larvæ had advanced toward their final change, possibly within a week or ten days. When the box was opened, the greater number were found in cocoons, while the remainder wandered about, as if in quest of food. The latter the author removed to another box, where they were provided with abundance of food. After three or four days they began to assume the chrysalis form. The first batch proved to be males without exception, while the last batch proved, with but two exceptions, to be females. (The whole number in the two batches was about sixty.)

Mr. Gentry then details further experiments made by him to decide this question, and states that the result was always the same. He adds the following facts, which came under his notice in the course of his observations and experiments: 1. That males are the invariable result when the larvae are fed on diseased or innutritious food; 2. That in the fall, when the leaves have not their usual amount of sap, males are generally produced; 3. That more males are produced late in the season than females; 4. That the sexes, in early life, cannot be distinguished, the change being brought about, late in life, by the conditions of nutrition.

Intensity and Patience required in Scientific Work.—Whether in original work or in elaborating work already done, scientific labor, when conscientiously performed, is necessarily slow and exhausting. M. de Candolle, the great French botanist, has recently brought to a conclusion, with the seventeenth volume, his great "Prodrome of Plants," stopping at the completion simply of the Dicotyledones. It was begun by his illustrious father, Augustin Pyramus de Candolle, about 1816, who worked at it until his decease, in 1841. It was continued by his son Alphonse, who called to his aid other famous botanists, his son Casimir among them. With true naïveté the author pleads necessity of stopping at the point now reached—"ne tertiam botanicorum generationem occideret!"—lest the undertaking should kill off a third generation of botanists. In a supplemental pamphlet he gives his opinion that the Phanerogams, estimated at 110,000 species, might, by distributing the task among twenty-five botanists, be worked up in about fifteen or sixteen years. He says that in his father's time one could elaborate at the rate of ten species a day, but that now a faithful monographer (or specialist), under the modern requirements, can seldom exceed 300 or 400 species per annum—that is, about one species a day!

Rationale of Double Flowers.—That the tendency in plants to produce double flowers is a natural one, and not exclusively evoked by the florist, is shown by Mr. Thomas Meehan, in a communication to the Philadelphia Academy of Natural Sciences. Many of the commonest wild flowers, which no one would think of cultivating, have double flowers in cultivation, which were no doubt originally found wild; for instance, various species of ranunculus. The author had himself placed en record the discovery, wild on the Wissahickon, of a double Saxifraga Virginica, and Dr. James Darrach had found in the same location a double-trailing arbutus. There are in plants two methods by which double flowers are produced. The axis of a flower is simply a branch very much retarded in its development, and generally there are, on this arrested branch, many nodes between the series forming the calyx, or corolla, and the regular stamens and carpels, which nodes are entirely suppressed. But, when a double flower is produced, sometimes these usually suppressed nodes become developed, in which case there is a great increase in the number of petals, without any disturbance in the staminal characters. But, at other times, there is no disturbance of the normal character of the axis. This was the case with the trailing arbutus discovered by Dr. Darrach.

Land-Plants in Lower Silurian.—It has hitherto been supposed that the Silurian age was one in which an absolutely unbroken ocean enveloped the earth. Dr. Dawson made it probable that land-plants existed in the Upper Silurian, or latter Silurian age. Leo Lesquereux, in American Journal of Science and the Arts, has wellnigh demonstrated that dry land existed in the Lower Silurian age. He communicates the discovery of two small specimens representing branches or small stems of a species referable to Sigillaria, and found on Longstreet Creek, near Lebanon, Ohio, in clay-beds positively referable to the Cincinnati group of the Lower Silurian. With the exception of these Lebanon specimens, the geological formations of the United States have not afforded as yet any records of plants earlier than those of the Lower Devonian.

The Uses of Bees' Wings.—At the lute Convention of Bee-Keepers at Louisville, D. L. Adair read an essay on the various uses of the bee's wings, in which he holds that, besides flying, the wing of the bee serves two or three other important ends. The horny frame, upon which the fine membrane of the wings is stretched, is composed of hollow tubes of a hard substance called chitine. These tubes are double, being one tube inside of another. The inner ones are extensions of the tracheæ, through which the air circulates in breathing; between this and the other tube is a space through which the blood circulates. The blood is brought in contact with the air through the thin walls of the air-tubes, just as the air and blood are brought together in the human lungs, and with the same effect.

The nervous filaments in like manner pass to the wings; they follow the respiratory tubes and all the fine venations of the wing, terminating in every part of its surface in papillæ, which in all animals are the vehicles through which sensations are perceived. Hence we may infer that the wings are the organs of some sensation. Are these nerve-filaments intended merely for noting tactile sensations? Mr. Adair is of the opinion that by means of them the bee is made conscious of odors. "Some naturalists have suggested the antennæ as the organs of smell; but, as they appear to be poorly adapted to perform such an office, it is just about as likely that they smell with them as that they see with them. Invisible particles emanating from odorous bodies, coming in contact with the olfactory nerves, produce the sense of smell. These atoms are mixed with and floating in the air, and, in order to collect them, a considerable volume of air must be made to pass over their surfaces—a thing which the wings certainly accomplish in an eminent degree."

The sense of hearing in bees has never been localized by naturalists, though some have supposed that the antennæ are the organs of this sense also. "What appendage of the bee," asks Mr. Adair, "would be better suited to receive sound-vibrations than the thin, stiff membranes composing the wings?"

The Lignite-Beds of the Rocky Mountains.—The opinion having been advanced that the so-called lignite-beds of the Rocky Mountains have been formed by the heaping of drifted materials, and not by growth in situ, Mr. L. Lesquereux replies as follows, in Silliman's Journal, to one of the arguments urged in favor of the opinion—viz., that the under-clays of the lignite-beds have no roots: "I can say," he writes, "from repeated and personal observations, that most of the lignite-beds of the West, which have passed under my examination, have the under-clays full of rootlets or of roots of the floating plants, which were the first, generally at least, to contribute to the formation of the bed of combustible material by their débris. At the Raton Mountains, at Cañon City, at Gehrung's, near Colorado, at Golden, Marshall, Black Butte, etc., the coal is everywhere underlaid by chocolate-colored shale, often a compound of these roots or rootlets, so compact, indeed, that they cannot be determined, nor their forms distinctly recognized. Of coarse, the under-shales do not contain any roots (true roots of trees); the coal of the carboniferous, too, never has any, for the good reason that trees do not grow in water, and that they only invade peat-bogs when the ground is solid enough to support them. And even then the roots grow horizontally, and do not descend deep into the matter which, generally impregnated by water, is to a degree inaccessible to atmospheric influence.

The so-called roots of the clay-beds of the carboniferous measures, or the Stigmaria, are not roots, but floating leaves. And even their cylindrical stems are rarely found in clay-beds; only their leaves fill them just as the radicles of water-plants fill the clay of the Tertiary lignite. It is, however, a fact that some of the lignite clay-beds, and those of the coal-measures, too, are clean or without admixture of vegetable remains, even of rootlets. But when the peat is beginning its growth at the surface of a somewhat deep basin of water, whose bottom has been rendered impermeable by the deposit of clay (which always precedes the deposit of woody materials), this surface-peat is often thick and compact before it is forced down and comes in contact with the clay; and, in that case, therefore, the clay is pure, or is not penetrated by roots or rootlets. There are, of course, some beds of impure lignite, whose origin is due to drifted wood, especially along large rivers. One is known at the mouth of the Rhone, in France. I have seen some deposits of the kind in Southeastern Arkansas, near the Wachita River. The great Red-River obstructions may become in time lignite-deposits. But all formations of this kind show their origin by their composition, viz., sand mixed with carbonized matter, sandy bottom, perforated, too, in various directions by drifted stems, etc. Nothing of this kind has been observed in the beds of lignite of the West, at least not in those which have come under my examination."

Geology of the Land of Moab.—Late explorations in the land of Moab by Dr. Tristam have disclosed some interesting geological features in that region. The doctor's observations were mainly confined to the highlands, which are in reality a set of terraces, or table-lands, rising to the eastward from the shores of the Dead Sea—attaining, in a distance of 35 miles, a height of between 4,000 and 5,000 feet. These table-lands are cut at right angles into deep gorges or ravines, by streams which now flow, or at some former time have flowed, westward into the Dead Sea. Some of the gorges are 1,800 feet deep, with perpendicular walls, from which a good idea of the geological structure of the region may be obtained. The surface of these highlands is composed of chalk, which rests upon a limestone formation, regarded by some as nummulitic and by others as Jurassic. The chalk and limestone together are from 1,200 to 1,500 feet thick. The limestone is supported by new red sandstone, the line where they join being well defined. It is from this line of junction that the hot springs, so celebrated in Roman times, gush forth. The water of these springs has a temperature varying from 100° to 143° Fahr. The salt-hills at the south of the Dead Sea, like the tablelands just spoken of, have been gouged out by the action of water, and present along their face numerous columns and pinnacles of salt, that are being rapidly worn down by the action of the weather.

Etiology of Typhoid Fever.—Prof. I. Buckman writes to the Gardener's Chronicle concerning the discovery of a microscopic fungus in water, the drinking of which was suspected of developing cases of typhoid fever. We give the main points of this communication. Some years ago Prof. Buckman examined the spout of a pump which had supplied water to a family attacked by typhoid. It was found to be lined with gelatinous matter. Under the microscope this substance was seen to contain some elegant branched confervoid or fungoid growths, intermixed with which were minute ovoid cells. As these fungoids require nitrogen for their nourishment, the author inferred that the supply came from some neighboring cesspool. He next went to the exit-drain of the town sewerage, and there found bits of sticks, leaves of water-plants, and the like, more or less covered with this same gelatinous matter.

The author next detected this fungus in water used by his own family, some of whose members were severely attacked with typhoid fever. A defective drain in the neighborhood of the dwelling having been set to rights, and the whole of the water pumped out, the water has since been of excellent purity. Having cited two other analogous cases, Prof. Buckman speculates as follows on the mode in which this fungus acts after having been admitted into the animal economy: "How it acts it would be difficult to determine, but it is at least conceivable that the spores of the fungus may get into the circulation, and bring about changes in the fluids, after the manner of yeast in beer; and, if so, the seeds of the fungus would be likely to develop rapidly, if they came in contact with milk, or water containing nitrogenous matter. 'A little leaven would leaven the whole lump,' and, as it appears to me, in this way much disease may be accounted for. The microscope, then, will enable us to make out the presence or absence of this fungoid or confervoid matter in foul water, and my own observations confirm me in the view that, being present, it is highly dangerous, and, if its cause can be removed, and the water made pure, all danger from this source at once ceases, while if it cannot it should be at once disused, and pure water be sought for elsewhere."

A Sun-driven Engine.—G. A. Bergh, writing in Poggendorff's Annalen, on the application of solar heat as a motive power, says that the engine which is to serve for this purpose must employ some liquid with a very low boiling-point. There are several such liquids—sulphurous acid, methylic chloride, methylic ether, etc. Of all of these, sulphurous acid best deserves attention, as it has several useful properties for the end in view. It is not too difficult to condense, and it can be got at a moderate price. Now we have got the principle on which we must construct our solar engine. Conceive a vessel, filled with sulphurous acid, exposed to the sun's rays; the tension of the sulphurous-acid vapor, if the temperature of this vessel A exceeds that of the surrounding air by at least 10° to 20°, must be from one to three atmospheres higher than that of the sulphurous-acid vapor in another vessel, B, similarly filled with sulphurous acid, but which has only the temperature of the surrounding air. We can thus arrange an engine which agrees in principle with the steam-engine, with merely this difference, that the water is replaced by sulphurous acid, and the fuel by the solar heat; while the vessel exposed to the sun's rays represents the steam-boiler, the vessel kept at ordinary temperature may represent the condenser. The sulphurous acid condensed, after doing work in the vessel B, could easily be driven back, by a force-pump, into the vessel A. The capability of work of such a machine must naturally increase with the amount of heat communicated to vessel A or be proportional to the surface exposed to the solar rays.

An establishment, furnished with a machine like this, might carry on its work while there was sunshine, but, in default of this, would be brought to a stand-still. True, the solar heat might be replaced by the heat of the air, if the temperature of the air were pretty high, and one had at hand a refrigerating substance like ice. But, as this is not always the case, the establishment should have, besides the sun-machine, an apparatus which might "store up" some of the work done by this. As such, Natterer's apparatus for condensing carbonic acid might be used. If a supply of carbonic acid were kept in a large gasometer, the Natterer apparatus might be fed from this. In a wrought-iron vessel, thus filled with liquid carbonic acid, we should thus have an enormous store of mechanical force, which might be made to replace the action of solar heat in the sun-machine, partially or wholly. After work done, the carbonic acid, become gaseous again, might be collected in the gasometer. Or, again, the sun-machine, while in action, might drive an ice-machine, and might, in default of sunshine, profit by the ice it had produced, for maintenance of its working.

The Movements of Drosera.—Prof. Asa Gray, commenting in the American Journal of Science on a paper by A. W. Bennett, on the movements of the glands of Drosera (sundew), remarks that the author's description of these movements does not do justice to the facts, as observed by Dr. Gray himself. Mr. Bennett observed not only the bending in of the glands upon the body of the insect which lights on its leaf, but that "the sides of the leaf had also slightly curved forward, so as to render the leaf more concave." With us, says Dr. Gray, the leaves do much more than that. As well in Drosera rolundifolia as in D. longifolia, the end of the leaf folds over upon the base, or nearly like a shut hand, thus fairly inclosing the captive insect.

He adds that, when Mrs. Treat's account of this infolding of the leaf was published, in 1871, the discovery was thought to be new. But he has since found that the infolding of the leaf, as well as the intrusion of the glands, was discovered by Roth in 1779. The only real addition to our knowledge—this old knowledge, recently reproduced—is that contained in the latter part of Mr. Bennett's communication, which is to the effect that Drosera acts upon bits of raw meat just as upon a living insect, but is motionless toward inorganic bodies, and, in his experiments, to bits of wood and of worsted. In the published report of the communication no allusion is made to the history and record of all these discoveries, but Prof. Gray claims for Mr. Darwin the credit of having been the first to discover this difference of behavior of the drosera-leaf to different substances. He says that there are other still more curious observations and experiments of Darwin's upon Drosera and Dionæa, which it is hoped will soon be published.

Ocean-Steamships.—A writer in the Evening Post notes some of the principal shortcomings of the ocean-steamship of the period, and offers some practical suggestions as to the proper construction of a passenger-steamer. The ocean-steamer of to-day is simply a huge freight-boat. She is somewhat larger, and perhaps a trifle swifter, but certainly not any safer, than when she first crossed the Atlantic some thirty years ago. It would seem absurd if our railroads had no passenger-cars, and we had to travel about the country strapped on to the roof of a freight-car. Ocean-travel is quite as absurd, and even more dangerous, for our tier of state-rooms is strapped to the top of a heavy iron box, loaded with heavy freight, which, in the event of a sudden blow, goes to the bottom as if it were made of glass. According to the writer in the Post, the passenger-steamship should be of about the same length as at present, but broader and shallower, with lines adapted, not to carrying capacity, but to speed; the chief novelty, however, being that the entire hull, excepting the spaces required for engines and coal, would be filled up with very small air and water-tight compartments or cells—enough to make the ship a gigantic life-preserver. All the state-rooms and quarters would be on the main-deck. The cellular construction of the vessel would add greatly to her strength, while her lightness would admit, at least in ordinary weather, of great speed, and her model would greatly diminish the rolling so provocative of sea-sickness.

As regards the question of expense, while the first cost and daily outlay would net exceed those of the present style of steamer, the passenger-steamer could make twice as many trips in the year, for she would not only be actually faster, but would save much time between voyages which is now spent in discharging and receiving cargo; for the same reason, after landing her passengers, she could start again in a day or two on another trip. Such a vessel might be disabled by collision, but it is hardly possible that she could be sunk by any form of accident that we are familiar with.

Tarantism.—Tarantism is the title given by physicians to an epidemic nervous disorder which prevailed in Italy, and more particularly in Apulia, during the middle ages. It was supposed to be caused by the bite of the tarantula, a species of spider found in Southern Europe, and very plentiful in the vicinity of the city of Taranto, whence it derives its name. The disorder, whether caused in the first instance by the bite of this spider or not, was capable of passing from subject to subject by a sort of sympathy, and thus the affection would spread to hundreds and thousands of the population, without distinction of sex or age. Analogous nervous diseases, known as St. Vitus's dance, or St. Guy's dance, prevailed in Germany, France, and England. A recent writer on "Mental Disease," W. A. F. Browne, gives the following account of these singular affections:

"In all these affections," says he, "which spread over great masses of the population, Teutonic and Celtic, children and octogenarians alike, there were observed wild and exuberant excitement, delusion, and antipathies, with uncontrollable impulses to run or leap, all such movements ultimately passing into dancing, which was generally aggravated, though sometimes mitigated, by music. These dancers were impelled sometimes by imitation, sometimes by fanatical exaltation, sometimes by terror and the fear of being poisoned, and it was when under the latter emotion that harmony seems to have been most powerful and curative. Airs (tarantelle) have been preserved which were employed in arresting or moderating the frenzied rotations and leaps of those urged on by dread of the bite of the tarantula, and by other causes; and that some interference was required is evident, for, although large numbers of those affected recovered, many resisted all coercion, and danced themselves to death."

The tunes which were regarded as remedial are said to have been of peculiar character, and to have contained transitions from a quick to a slow measure, and to have passed gradually from a high to a low key. The sensibility to music was so great that, at the very first tones of their favorite melodies, the affected sprang up, shouting for joy, and danced on without intermission until they sank to the ground exhausted and almost lifeless. Although thus excitable, no external or audible music was requisite to suggest or sustain such movements. Apparently stimulated by some internal rhythm, the performers danced, sometimes with infuriated, but always with measured steps, wheeling hand-in-hand in circles, not merely from street to street, but from town to town, dropping down when exhausted, but having their places supplied by fresh recruits. When under this inspiration, the rudest of the victims exhibited gracefulness in dancing, and manifested displeasure when false notes were introduced into the music.

Utilization of Sewage.—The following facts, with regard to the utilization of the sewage of the city of Paris, are taken from the official returns: At Clichy, a bend of the Seine forms a sandy, level peninsula, of some 5,000 acres. The barrenness of this peninsula is proverbial, and hence it was on this land that a portion of the city sewage was first directed, with a view to put the utility of this kind of fertilization to the severest possible test. The preliminary works were begun in 1868, and completed in May, 1869. From that time between 5,000 and 6,000 cubic yards of the sewage have been raised daily by engines of 40-horse power and centrifugal pumps, and of this two-thirds were received into tanks for chemical manipulation, the remainder being applied to a piece of land 12 or 15 acres in extent. At the end of several months the results of this experiment upon a naturally poor soil were such that the neighboring farmers asked to be included in the benefits derived from the sewage. Owing to the extreme permeability of the soil, 20,000 cubic yards of sewage could be annually absorbed per acre, and the farmers obtained crops of 70,000 lbs. of cabbages, 60,000 lbs. of carrots, and 150,000 lbs. of turnips. All land suitable for irrigation rose in value. No evil effects on the health of the inhabitants could be detected, and a village sprang up around the works. A Parisian perfumer established his manufactory on the outskirts of the irrigated land, and obtained a supply of the sewage-water for his gardens of aromatic herbs, more especially of peppermint. It is worthy of note, in this place, that the finest mignonette of Covent-Garden Market, London, has long been grown from sewage-irrigated soil.