Since the publication of these observations, I have had additional proof of the non-earthy character of the prisms; for having mounted some, carefully cleansed, on several glass slides, and covered them with plates of thin glass, for future microscopic observation, I found, after some months, that they had wholly disappeared, leaving scarcely a trace of their existence, though exposed only to the atmosphere, and this admitted only under the edges of the plates of glass. If they had been earthy crystals, it is manifest that they would have remained unchanged both by the atmosphere and by potass.

The specimen whose portrait accompanies this little memoir lived for two or three days only, in a glass vase of sea-water. Generally I have not been able to preserve these forms in health for a longer period; though a fine specimen of Chrysaora cyclonota, whose history I have given elsewhere,* lived under similar circumstances about three weeks. A very gorgeous object was the Cyanea in captivity. The whole umbrella was of a fine rich blue, possessing a sapphirine brilliance and transparency, especially when the slanting rays of the setting sun shone horizontally through the mass, as it floated in its glass prison on our drawing-room table. This hue was deepest where the substance of the disk was thickest, while at the surface and edges it melted off into colourlessness. Yet the lower integument or sub-umbrella, being of a far deeper colour, the form of the inner dome, viewed horizontally, was quite broadly defined from the hue of the mass, and seemed like a solid hemisphere of glass within the mitre, of a blue so intense that the sun's rays could scarcely struggle through it. In this the vault-like clefts were fashioned, reminding us of those beautiful paperweights, in which some exquisitely folded pattern is seen within a perisphere of smooth clear glass.

It was interesting to observe that by lamplight the hue was very different. As I have often noticed that flowers which by daylight are almost purely blue, show by candlelight a prominent red element, before unrecognized, so this fine Medusa became of a fine imperial purple. I suppose the explanation is, that the blue ray is more weakly perceptible by artificial light, and is, therefore, overpowered by the red ray, though this may exist in the compound tint in actually a less ratio.

I could not detect any stinging property in the tentacles when touched by the hand. Its congener, C. capillata, is described as so formidable as to be the terror of bathers; and Edward Forbes has given us a graphic description of an unfortunate swimmer writhing, terrified and tortured, in the clinging grasp of its slimy threads. Much may depend on the varying susceptibility of the human skin to the poison in different per* Devonshire Coast, p. 363, et seq.

sons. Only a day or two ago I was engaged in capturing some lovely specimens of Chrysaora; a lady of my party, in lifting one, complained of being stung, while I lifted them without the slightest sense of such a phenomenon. So it is with some Anemones, the tangled snake-like locks of Anthea cereus may be handled by a man with impunity, while the tenderer skin of women and children smarts and reddens with the contact.*

* The subject of the poison-apparatus in a kindred group of animals I have treated in considerable detail in my Actinologia Britannica (Introd. pp. xxii. -xl.) I hope it may not be considered out of place if I here cite some observations of an American zoologist, confirming some of the most important of my conclusions, and adding other information of much value. Professor Henry James Clarke, of Harvard University, Cambridge, Mass., in a very able article, entitled "Lucernaria, the Caenotype of Acalephia," describes the cnide of this organism in the following terms :

"The nettling organs or lasso cells, which crowd the globular tips of the tentacles, are of two kinds, and both are imbedded in the intercellular substance which fills the spaces between the columnar cells of the outer wall. One kind consists of an oval, thick-walled vesicle about 1-2000th of an inch long, or a little less, one end of which is introverted and projects in the form of a stout hollow shaft along the axis of the cell, about four-fifths of its length, and then, rather suddenly thinning into a slender thread, which is also hollow, it bends upon itself, returns nearly to the aperture of the cell, and, pressing closely against the inner face of the cell-wall, it forms a close coil, which terminates at the end opposite the mouth of the introversion. When the coil of thread is ejected, which is accomplished by sliding through the hollow axial shaft, which, in its turn, retroverts also, just as the finger of a glove is turned inside out, the whole aspect of the apparatus is changed. The oval cell is considerably diminished in size, and from its aperture the enormously enlarged hollow shaft projects in a straight line; the half of the shaft next the cell is cylindrical, and half as broad as the latter, with a slight expansion where it joins the mouth of the cell; the distal half abruptly expands into an oval form, half again broader than the cylindrical portion, and rapidly tapers into a smooth trihedral, twisted thread. The oval part of the shaft is endowed with three equidistant spiral rows of sets, which number about a dozen in each row. The set are comparatively large, and in length equal two-thirds the broadest diameter of that part of the shaft from whence they project. Each row makes but one turn above the shaft, and terminates as if in continuation of the angles of the trihedral thread. There is not the least trace of setæ or projections of any kind upon the trihedral thread, but it continues, with a very gradual taper, perfectly smooth to the blunt termination. The angles of the thread appear, at first glance, as if they might be spiral rows of setæ ; but a most careful and prolonged examination with one of Spencer's 4-inch objectives convinces me that they are truly the angles of a twisted trihedral filament. The extent of the thread is from twenty to twenty-four times the length of the cell. The other kind of nettling cell is much more simple in structure, but yet more remarkable. The introverted shaft is very slender, in fact no larger than the rest of the thread. It does not project into the axis of the cylindrico-oval cell, but presses close to the side of the latter, and extends four-fifths of the way to its opposite end, and then, bending abruptly upon itself, the thread passes with a long curved sweep nearly to the aperture of the cell, from whence it again returns with another long sweep, which is repeated eight to ten times, until the inner face of the cell-wall is lined by a close coil which winds lengthwise instead of transversely, as it does in the other kind first described. When extended the thread is from twelve to fourteen times the length of the cell. It offers not the least sign of appendages of any kind, but is simply a smooth round filament of uniform thickness throughout, except at the end, where it tapers slightly and terminates in a blunt tip. The cell itself, when retroverted, is sensibly diminished in size, and narrows rapidly into the prolonged filamentary portion. It would

FALLING STARS AND METEORITES.

BY PROFESSOR D. T. ANSTED, M.A., F.R.S.

FROM the earliest times-long before men had any idea of the calculations of astronomy, of the difference between planets and fixed stars, or of the vast distance of the nearest star not only from the earth, but from any part of the solar system-the singular phenomena of falling stars had been noticed, and had connected themselves with feelings that will probably never be entirely eradicated from the minds of men. Thus in the same

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ancient Jewish history that tells us "the sun stood still, and the moon stayed," in order that Joshua might destroy a few more of his fleeing enemies, we read also, the stars in their courses fought against Sisera." Both these expressions are probably intended as no more than oriental pleonasms, but they indicate strongly the unalterable egotism of man, who will to the end of time regard himself and his affairs as the ultimate object of divine care.

When, therefore, on the tenth of August last, the usual annual shower of Nature's rockets was seen in the atmosphere -this storm of silent flashes and darts of light, mysteriously shooting from one point of the heavens towards another point, some with bright trails of light, some as fiery balls, some darts and arrows of light, and not a few ending as the rocket with an additional shower of sparks-many, perhaps, who were unaware of the natural history of these objects may have fancied that some extraordinary crisis was about to take place in American politics, or that Europe was about to be convulsed by the refusal of Russia to treat the Poles as anything but wild beasts. For a very long time, however, the corresponding date, and also the 12th November, and several other days in the year, have been remarkable for an exhibition of the same kind without political consequences.

Kings have been born and died; revolutions have been commenced and carried out in human affairs; battles have been won and lost, but the day of the shower of falling stars has not much altered, though the clear sky has sometimes favoured, whilst at other times the clouds have concealed, the mysterious operations of nature.*

seem to be perfectly incontestable that, as the cell diminishes in size with the expulsion of the thread, it forms the propelling power, and, by the contraction of its wall, forces its contents outward."-American Journal of Science, May, 1863.

It is a remarkable fact that in some very ancient records the date assigned to the phenomenon is many days earlier, even so early as the 25th July. In Thessaly there is a tradition that the heavens open and lights appear on the festival of the Transfiguration (6th Aug.) The reason is obvious. The civil time we

That the great crowd of falling stars is seen chiefly on the two occasions whose dates have been just given, is unquestionable; but they are also numerous on the nights preceding and following the principal ones, and they are visible, though less frequently, during every fine clear night throughout the year.

Few subjects are more interesting than the inquiry into the meaning of these appearances, and they have from time to time been noticed in these pages. Within the last few years there has been an enormous quantity of material collected, both concerning the actual history of showers of stones and meteors, and the details of remarkable examples. Few who have not followed the course of inquiry are aware how much material exists, how frequent and portentous the larger instances have been, and how very much positive proof there exists of the materiality of some, at least, of the phenomena, in the existence of many hundred well-authenticated specimens of fallen stones in several of the principal museums of Europe. A few accounts of remarkable cases will be both interesting and useful in preparing the reader for a consideration of the explanations that have been offered for the various facts recorded.

And, first of all, with regard to the number of these appearances. In the present year, at Cambridge, nearly a hundred meteors were counted by a single observer in one part of the heavens between 10 P.M. and 1 A.M. They were most abundant towards midnight. On another occasion, some years since, 565 were counted on the corresponding night, but this was by six observers, each taking a part of the heavens, and continuing the observations for five hours, from 10 P.M. to 3 A.M. There has hardly been an occasion, when the sky was clear, on which a very large number of these curious appearances have not been seen on the nights now known to be rich in them. On other nights they are occasional, but on these they succeed each other rapidly. It is not reasonable to suppose that they are limited to the hours of darkness, and thus it becomes probable that uninterruptedly, during certain days in the year, and at all other times with less regularity, and to a smaller extent, these lively messengers are constantly communicating between the world and the outer space; these visible messages along the telegraph of space are always reminding us that our earth is not wandering in a solitary path, but is surrounded by myriads of small fragments of matter, made visible when they pass through our atmosphere, or when we pass near them in their

course.

There are two distinct classes of phenomena connected with use does not correspond exactly with sidereal time, and the phenomena thus appear to occur gradually later and later in the year, though the intervals between their recurrence is really the same.

the subject of meteors. These are, first, the phenomena of light -the falling stars as seen in the atmosphere; and secondly, the fallen bodies themselves, whether called meteorites, aërolites, fire-balls, bolitos, or thunderbolts-the fragments of foreign matter now and then seen to fall on the earth from the sky, but more frequently found near the surface, and identified by their peculiar mineral characteristics.

The meteors are of various kinds, so various that it is almost impossible to bring together within a limited space such an account of different records as shall give even a faint idea of the appearances described by those who have seen them. Limiting ourselves to the remarks of astronomers, and persons fully accustomed to observe and describe what they see, we yet find accounts as strange as if they were dreams of sick men.

The vast majority of the strange lights seen in the heavens are well described by the expression, Falling or shooting star. Suddenly a star, or what appears a star, shoots rapidly from one point in the heavens to another, or seems to fall downwards towards the earth, and disappear. Of such phenomena, whatever they are, it is not too much to say that thousands sometimes take place within twenty-four hours; that on special occasions this number may be multiplied many fold; that they are common even at all other times, and that, in fact, they are as little exceptional as clouds. It is impossible to identify and measure any particular one, for they are too frequent and too much alike. They are seen from every part of the earth's surface almost every fine night throughout the year, in every quarter of the heavens, and there cannot be the smallest reason for supposing that they do not occur by day as well by night, in foul weather as well as fair.

Of these ordinary shooting-stars, special observations are made at certain dates, because they are then most numerous and most definite. At such times, as we have seen, they are counted by the hundred, often by hundreds in the hour, in all the principal observatories, and by many private individuals. On such occasions they appear, most of them, but not all, to proceed from near one point in the heavens, and disappear in another. These points are generally the same.

Of the size of these meteors it is impossible to give any correct idea. It is usual to compare them to the stars, and speak of them as resembling stars of the first to the third magnitude. It seems quite impossible to judge even relatively of their actual dimensions by observations of this kind, even when for any reason it has been possible to estimate their height.*

*An ingenious and very simple instrument for estimating the altitude of these bodies was described in the INTELLECTUAL OBSERVER, vol. iii., p. 165.