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pared with Epilobium; the stamens of Geranium as compared with Erodium. Where the reduction has been unsymmetrical, I suspect it has been due to insect adaptation : as in di-dynamous

stamens.

As soon as decussate leaves are secured, then we possess the basis for all ordinary leaf-arrangements.

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Dr. Airy alludes to non-existing orders, 1, but in the Jerusalem artichoke the secondary series,,, II, 15, occurs frequently, and arises from the breaking up of "tricussate whorls in an exactly similar manner to the primary series,, , &c., arising out of opposite leaves. On the other hand spirals do not easily, if ever, return to whorls. If any one will notice how curiously the above is executed in the Jerusalem artichoke, he will see that there is evidently some power at work in the plant which, as it were, compels the spiral to form, and to form mathematically, will be convinced, I am sure, that a "twist" is very far from being the cause-there being none whatever in the cases mentioned above: and further, when whorls break up, the leaves are at first quite irregular, but they gradually "right themselves," acquire the proper angular divergence, and then form some member of the spiral arrangements to perfection. GEORGE HENSLOW

Flight of Projectiles

IN reply to the letter of "W. Hope," in NATURE of March 13, I request permission to state that by a simple formula, I meant one that would be easily understood. I did not intend the word simple to be taken strictly in its mathematical sense. It is easy for Mr. Hope to employ symbols to represent the initial velocity, angle of elevation, or any other additional particular he may consider necessary for the solution of my problem. No one possessing the most elementary knowledge of the theory of projectiles can be ignorant of the disturbing elements to which your correspondent refers, or of others to which he makes no allusion. But these cannot be accurately estimated, and, therefore, must necessarily be neglected in a theoretical investigation. I do not anticipate that they will be found to vitiate the results of theory to the extent Mr. Hope supposes.

mum.

In the practical application of the formula for which I have asked, the numerical values of the general symbols, would be the mean of carefully conducted experiments. Thus the trifling variations arising from slight differences in the charge, the amount of fouling, or other causes, would be reduced to a miniThe variations in the force and direction of the wind would often neutralise each other. For these reasons I cannot agree with Mr. Hope in thinking that the calculation would be either "useless or deluding," on the contrary I believe it would be valuable as indicating a mean deflection, about which the experimental deflections would be found to group themselves. Of one thing I am certain, that it would enable us to bring home to the soldier the great effect of wind in deflecting the bullet, and perhaps it might assist us in dispelling the notion of absurdity which is inseparably associated in his mind with the effort to hit something by aiming at nothing. In accomplishing this one of the greatest obstacles to the development of skill in rifle-shooting would be removed.

If Mr. Hope will kindly supply me with the formula which I have asked for, I can assure him that however lightly he may appreciate the results of his labours, by me, at least, they will be valued, and, I venture to hope, made practically useful. Surely he cannot be in earnest in denouncing all theory which approximates to, but does not exactly accord with practice, as "bastard science, or pedantry." If this dictum be sound, I can only say it would be easy to show that a great deal of the science of our day, gunnery science in particular, is spurious. General Didion, a high authority, did not consider my problem unworthy of investigation. In the Cours Elementaire De Balistique, he has given a solution which I regret is rather too complicated for my purpose. I should imagine that he would be the last person to expect his theory to afford more than a rough approximation to the results of practice. Hence I conclude that in publishing his calculation for the benefit of the French army, he could have had no conception that his science was "bastard science, or pedantry," and must have been unconscious what a "mischievous unpractical pedant" he was.

ROBERT REID, Sergeant- Major School of Musketry, Hythe, March 17

Deep Sea Soundings near the Equator

school-ship Mercury, occupied at present in taking deepes soundings under the orders of the Board of Commissioners of Public Charities and Correction of New York, has been sent to me by General Bowen, of that Board, who takes much interest in the subject. It will doubtless be gratifying to many of your readers :

"Our Casella-Miller deep-sea thermometer worked admirably. This beautiful instrument stood the test at a depth of 2,040 fathoms, two miles north of the Equator, in longitude 22° 16' W., when it indicated a temperature of 35° F.; at 1,000 fathoms 38°; at 400 fathoms 41°; at 300 fathoms 44°; at the surface 81°; in the air 80°..

"On our track from the Canary Islands to Rio we found the temperatures at uniform depths to vary about 2°. Our speci mens of the bottom from the volcanic region differ in every respect from those obtained in other parts of the ocean." JOHN WM. DRAPER

University, New York, March 6

SURVIVAL OF THE FITTEST

THE doctrine of the "survival of the fittest" must be strangely understood in some quarters. The American papers report Prof. Agassiz as having expressed himself in this wise at a recent meeting of the Massachusetts State Board of Agriculture, of which he is a member: "I do not know how animals originated; a brilliant imagination that of Darwin; a very necessary faculty in the scientist. The sense I know too well to misquote him. Hasty generalising of observation is Darwin all over. Natural selection is out of generation. Natural necessity, what is it? Do we find that only the strong beget families? Observe plants at the foot of the White mountains, where are large trees, and so up to the summit, where they are mere shrubs. The weak may and do survive as well as the strong. Ignorance lies at the base of the discussion."

Probably no one naturalist, however eminent, can be expected to know everything, or even all simple things. Can it be possible that Prof. Agassiz supposes (as his argument seems to require) that the dwarf trees in question grow and survive near the top of the mountain, notwithstanding they are not the fittest, rather than because they are the fittest, for the conditions? And does he conceive the doctrine of natural selection to be founded upon some idea of an abstract fitness, irrespective of the conditions, and not upon the survival of the fittest under and in consequence of the conditions? Surely the argument brought against the doctrine is a good illustration in its favour, only an extremely simple and elementary one.

We never could quite comprehend why Prof. Agassiz should give himself so heartily and persistently to the work of demolishing the doctrine of the derivation of species, in all its forms, considering how large and honourable a part he has himself taken in laying the foundation upon which the modern doctrine has been built. Of these foundations none is stronger than the capital one, generally supposed to be established by him, that the succession of species in time corresponds mainly with that in systematic rank, and is also somehow paralleled in the development of each individual of the higher ranks. So that, in view of his continued but unsuccessful efforts to drive the incoming doctrine out of the land, we could imagine him addressing his own important discoveries in the words used by Balak to Balaam :

"What hast thou done unto me? I took thee to curse mine enemies, and behoid, thou hast blessed them altogether."

SUB-WEALDEN EXPLORATION.-SECOND QUARTERLY REPORT

AFRESH survey of the Lower Wealden beds in castern

Sussex by the officers of the Geological Survey De

THE following extract from a letter of the captain of the partment has quite recently been made. The whole dis

trict has been recently visited by Messrs. Bristow, Topley, and Drew, and it has been decided to sub-divide the strata hitherto known as the Ashburnham beds into two divisions.

The upper portion, consisting of the mottled clays and shales, will henceforth be called the Fairlight beds, while the lower portion, consisting of shelly limestone intermixed with calcareous shale and gypsum, will retain their old title; unless (as is confidently anticipated) they will be found to represent the Purbeck strata, in which case they will be known as the Sussex Purbecks. In reference to our own immediate object, this recent survey has established beyond doubt that the site of the boring is by far the best that the county of Sussex presents for the purpose.

Quite unexpectedly, on January 28, at a depth of 131 feet, a stratified mass of pure white crystalline gypsum (statuary alabaster) was reached. This proved to be over

[blocks in formation]

4 feet in thickness; it was succeeded by 10 feet of gypseous marl; then by 3 feet more of alabaster. Afterwards, we passed through 15 feet of gypsum (more or less impure) varied by seams of crystals of selenite. This discovery has been most opportune. No such accumulation of gypsum was ever met with in Sussex before; and it is some consolation to know that our labour has not been all labour in vain: gypsum is a material which is commercially valuable.

Geologists may therefore inquire, "Where are we now?" The reply is given with caution, and under correction (as the shale seems singularly free from fossils), but as blocks of gypsum are found in the lower strata of the Purbeck series, we assume we are near the base of that formation, and may with some reasonable confidence expect to be able to announce before another quarter is over that we are through these problematical beds, and into the Portland series or some subjacent formation.

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NEUE

WILHELM STR.

CLOSE TO THE BRANDENBURC GATE. AT A SHORT DISTANCE OPENS ON THE "LINDEN,"

SOUTH

DOROTHEEN STR.

SCHLACHT

CASSE

Plan of Physiological Laboratories, Berlin

from those who will "give, hoping for nothing again,' except scientific discovery.

The question of Finance begins to excite some anxiety in the mind of the treasurer. The amount required for machinery, sheddings, &c., has more than doubled the original estimate. Coals, tools, and labour, are each dear, and likely to remain so. The difficulty of access will THE NEW PHYSIOLOGICAL LABORATORIES greatly add to the original estimate of expenses. A large portion of our promised aid is given on conditions which render it unavailable at present.

If 200/. could be raised shortly, it would enable the Finance Committee to authorise the call of the second 1,000/.; and till this is done we are approaching insolvency. If each existing subscriber would kindly undertake to bring the matter under the notice of some neighbour or friend, we should not only soon raise all we want at present, but be relieved from anxiety for the ultimate prosecution of the enterprise.

We have nothing to do with the cornmercial value of our present or future discoveries; this will be freely given to those who can utilise it. We can only ask for aid

TH

AT BERLIN*

HE building of the new laboratory will begin on April 1. The plans are almost ready, and a most glorious place it will be, undoubtedly the finest physiological laboratory as well as the largest which was ever dreamt of. Besides the large theatre, and every possible accommodation for the lectures, it will contain rooms for collections, for a library, a smaller class-room, apartments for three assistants, lodgings for the servant and his family, &c. Then, there are five distinct laboratories most scientifically connected; (1) for physiological chemistry; (2) for physical physiology; (3) for vivisections; (4) for

* Extract from a letter communicated to us by Dr. Bence Jones.

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chambers looking to the south for optical experiments, rooms for a respiration apparatus, and all sorts of stables, an aviary, a ranarium for the summer, and one for the winter, &c. There is to be a dwelling-house close by, in fact so connected with the laboratory that from the study a lobby and a flight of stairs lead to the private laboratory. The House has been designed entirely according to the English fashion, and wonderful to say, hitherto has not yet met with serious opposition from the architects and the authorities. On the same premises there will be (1) Helmholtz's laboratory and dwelling-house; (2) a laboratory for inorganic chemistry; (3) one for pharmacology, under Leibreich. The accompanying sketch will give an idea of the whole. It covers an area of 4 acres. The style of building is to be magnificent, much more so than

ON THE SPECTROSCOPE AND ITS APPLICATIONS

VI.

IN the first place, then, what does the spectroscope tell us with regard to the radiation from the sun and the stars? And here I ask you to neglect and banish from your minds for a time any idea of those dark lines in the solar spectrum that I drew your attention to on a former occasion. I hope I shall be able to explain them satisfactorily to you afterwards, but for the present I wish you merely to take the fact that our sun, but for the dark lines, would give us a continuous spectrum. The spectrum of the stars is very much like the spectrum of the sun. In Fig. 34 is seen a representation of the spectra of two stars, a Orionis and Aldebaran, mapped with the minutest care by Dr. Miller and Mr. Huggins.

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FIG. 35:

FIG. 36.

Fig 35.-Ring Nebula in Lyra, with its spectrum. Fig. 35.- Planetary Nebula in Aquarius, with its spectrum.

is desirable, because the costliness of the establishment increases the responsibility; but now that they are at it, they do not care for ever so many hundred thousands of dollars. All around the buildings, there will be an area, after the English plan, in order to mitigate the tremor occasioned by vehicles. In the Neue Wilhelmstrasse and the hitherto very nasty lane called Schlachtgasse there remains an open space facing the streets, so that the gardens intervening between the two great masses of building get as much light and air as is possible in the town. After all we are not so exclusively military as it may seem at a distance, and some of the French millions find their way into a scientific channel.

FIG. 37.--Spectrum of the Nebu'æ.-1, 2, 3, lines observed. Above, the solar spectrum is shown from tor; below, the bright lines of magnesium, nitrogen, barium, and hydrogen, in the corresponding!part of the spectrum. In both cases we should have a continuous spectrum but for the presence of the dark lines. I think you will see in a moment what I am driving at. Suppose the sun or stars composed of only sodium vapour, for instance, it is clear that their light analysed by the prism would give us no great indication of a continuous spectrum, we should merely get one bright line in the orange. But neglect the dark lines for a moment: dealing merely with the continuous spectrum of the sun and star, it shows that we have a something, whether it be solid or liquid, or whether it be a dense gas or a vapour, competent to give us a continuous spectrum. So we are justified in assuming that sunlight and starlight proceed from the incandescence of

a solid, a liquid or a dense gas or vapour. Again, suppose that instead of looking at the sun or the stars we observe the moon, as Fraunhofer did, as has been before stated, what will happen? We get a second edition of sunlight, in exactly the same way as we should get a second edition of the sunlight in the case of a reflection of it from a mirror; and therefore, if proof of such a thing were needed, the spectroscope is perfectly competent to show us that the moon gives us sunlight second-hand. The same in the main with Jupiter, Venus, Mars, and the other planets. If we study them and observe the dark lines we find that the lines which we observe are generally the same as those which we find in the spectrum of the sun. There are other points to which I shall have to draw your attention on a future occasion, but on the whole, the teaching of the spectroscope is, that all those planets are lit up by sunlight as we know them to be.

But we have not yet exhausted the wonders of the celestial field; we have dealt merely with the sun and moon, the stars and planets. What about the nebulæ, those strange weird things, dimly shining in the depths of space, both to the eye and in the telescope obviously

these three bright lines indicate that the nebulæ, instead of being composed of solid, liquid, or densely gaseous bodies-instead of being like the sun or stars-are really composed of rare gases or vapours. Mr. Huggins was enabled, in fact, to determine the gas in one instance, for one of the lines he found was coincident with one of the principal lines in the spectrum of hydrogen one of the other lines possibly being due to nitrogen. And now comes another extremely important point, showing the importance of studying the most minute changes in gaseous spectra, for Mr. Huggins, who knew the spectrum of hydrogen and the spectrum of nitrogen well, and who knew how extremely complicated those spectra are at times, was much astonished at finding only one line of hydrogen and one of nitrogen, and attempted to account for the singleness of the lines, first, by assuming a condition of the gas different from anything

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and distinctly different from anything in the shape of the sun or stars? The appearance of these peculiar bodies is sufficient to show us that we have here something very different from the sun or moon. What is it? You all know as well as I do that ever since nebule were discovered mankind have wondered at them, and wanted to know what they were; and you are also aware that it was not settled and could not be settled before the advent of the spectroscope, but that it could be settled in five minutes after that event. Mr. Huggins, who first observed the spectrum of a nebula, found that, instead of the continuous spectrum with which you are familiar in the case of the sun and the stars-always asking you to neglect the Fraunhofer lines, which I shall explain afterwards the light which he got from the nebula consisted merely of three lines. He was exceedingly astonished, so much so that he thought the instrument might be out of order. However, it became perfectly clear to him in a very short time that there was no mistake at all, and that all that the light which came from the nebula could do was to give him these three faint lines. No doubt you have anticipated my explanation. The nebulæ are composed of tenuous gases or vapours. After what I have said about the way in which the spectroscope at once picks out the difference between a solid or liquid, and a vaporous or a gaseous body, you will see at once that

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we meet with 1 our laboratories, and again by assuming an absorbing medium in space. But after Dr. Frankland and myself had made some observations on the spectra of hydrogen and nitrogen, we found it was perfectly easy to obtain, and sometimes when one did not want it, a spectrum of hydrogen or of nitrogen giving only one line, or nearly so ; so that by comparing the conditions which were necessary to obtain these conditions in our tubes with the conditions of the nebulæ, it was quite possible to make at all events a rough guess at what is the constitution of the nebulæ, so far as pressure or molecular separation goes. We find, for instance, this single line of hydrogen, and a nearly single line of nitrogen, when the pressure is so slight that you would say that the tube really contained nothing at all, and when, moreover, the temperature is comparatively low. Now, not only is this a fact, which we are quite prepared to assert, merely on the evidence rendered us by these tubes, but I think you will acknowledge that it is entirely in accordance with everything we know astronomically on this subject.

For the next application of the spectroscope in this direction, let us take a comet. The appearance of a

comet is probably well known to many, who will recollect the form of Donati's comet. Although, as you know, that comet appeared only about ten years ago, unfortunately it came too early for us to learn anything about it by means of the spectroscope. We have, first of all, an extremely bright nucleus; then a kind of semilune of greater brilliancy than the rest of the head, then what is called the coma, and the tail. The question which the spectroscope had to put to the comet was-of what is the nucleus composed, and of what is the tail composed. Prof. Donati, and Mr. Huggins especially, to whom we owe so much for his work in this direction, has made some observations on two small comets-I am sorry they were not larger-with considerable success. He found that in the comets he examined, the head gave out a light which very strongly indeed resembled the spectrum of carbon vapour. The spectrum of carbon taken with the spark in olive oil and in olefiant gas differs slightly; the spectrum as obtained from the latter consists of three bands or waves of light, which commence tolerably bright and sharply on the red side, and become gradually fainter towards the more refrangible side. These bands are severally situated in the beginning of the green, in the true green, and in the blue portions of the spectrum. Mr. Huggins has also observed the spectrum of Encke's comet, and has confirmed the result that he previously obtained, viz., that the spectrum of the comet is identical with the spectrum of carbon, as taken in a hydrocarbon. I should like to draw your attention, if there were time, to the way in which these spectra of the carbon spark taken in oil and in olefiant gas, differ.

I have not yet completed all I have to say on the subject of radiation. If, as we have already seen, we take a tube containing incandescent hydrogen and pass a series of intense electric sparks through it, we see that it gives out a red light, which may remind you of some other specimens of radiation which is supplied us by the skies. I allude to the red prominences which are seen around the sun, not in ordinary times, but when the sun is eclipsed. This representation gives you a good idea of what really is seen when the sun is eclipsed, when we have as it were a black sun instead of a bright one, | which is really nothing, but the body of the moon. Around this we have a ring of light, which is called the corona, and here and there in this corona we have what are called red flames and red prominences. These red prominences have also on closer observation been found to be only local aggregations or heapings up of a red layer which surrounds the outer edge of the sun. Here, then, it was quite possible that if the newly invented spectroscope were set to question these things, we should see at once whether they were solid or liquid, or whether they were gaseous or vaporous. If we got a continuous spectrum from these red things, we should know that they were solid, or liquid, or densely gaseous. If, on the contrary, we got a bright line spectrum we should know we were dealing with a gas or vapour. You also see that, as the light is red, the chances were that they were not solid or liquid, and then you further see that if the things do consist of a light which does give us lines, a determination of the exact position of the lines, and a comparison of these positions with those of hydrogen, sodium, magnesium, barium, or anything else, would teach us what these things were.

J. NORMAN LOCKYER

PROF. FLOWER'S HUNTERIAN LECTURES

TAR

LECTURES XIII. XIV. XV.

obtained in abundance from similar deposits in North America, and these can hardly be distinguished from those at present existing; in China likewise Pleistocene Tap.r's teeth have been found. In Europe during the same time they do not seem to have existed, although Elephants and Rhinoceroses were abundant. In the Pliocene and Miocene, Tapirs are not unfrequently met with at Eppelsheim, Auvergne, and elsewhere; perhaps they originated in Europe, and thence spread east into Asia, and on to America. Respecting their anatomical peculiarities, the teeth are forty-two in number, the anterior lower premolar being absent; the molars and premolars are much alike, forming a uniform series; the incisors are smaller than the canines, they have a small cingulum. The molars are a modification of those of Lophiodon, the transverse ridges are very prominent, and the cusp of the cingulum is less developed. The lower possess two simple transverse ridges, as in Lophiodon, but the last in the series wants the extra back lobe. The anterior nares are very open and the orbit is incomplete behind. There are four toes on the front foot, and three behind; the radius and ulna as well as the tibia and fibia are quite separate and well developed; T. bairdi is peculiar in that the mesethmoid cartilage is well ossified, and the maxillaries are specially developed upwards to support it.

The Paleotherida occur in the Upper Eocene only, they were first found at Montmartre and worked out by Cuvier; since that time they have been obtained from many parts of France, the Bembridge clay, near Yarmouth, in the Isle of Wight, and in Hampshire. Several genera have been separated off, and about a dozen species, from the size of a small rhinoceros downwards. In general aspect they must have been tapir-like. The maxilla curved downwards in front as in the tapirs; the orbital and temporal fossæ were also united, and there were large anterior osseous nares; the feet were much like those of the tapir, though they were more specialised in wanting the fifth toe to the manus. The typical fortyfour teeth were present; the incisors were more uniform than in the tapirs; the first pre-molar was rather rudimentary, the others formed a uniform series with the molars, which were wider than from before backwards, much pressed together, and with short crowns. They can be shown to have been developed on the type of Lophiodon, the outer wall bulging inwards, opposite the outer cusps, instead of outwards, giving the earliest indication of the lunate type of tooth; the transverse ridges were normal, and the internal cusps were slightly cut off from them, turning backwards as the rudiments of the posterior semilunes. The lower teeth presented a peculiarity here first noticed, each being formed by a double crescent, quite different from those of the tapir. The last lower molar had a third crescent behind as in Lophiodon and the Artiodactylata, but, different from the latter, in the corresponding milk tooth not presenting it. Palaplotherium was a smaller and earlier genus described by Owen from Hordle. In the upper jaw the first premolar was missing, and the corresponding lower one soon lost; the others were comparatively simple. The remains are very abundant, the feet were as in Palæotherium. Gervais has given the name Propalæotherium to a few teeth of another early form, intermediate between Lophiodon and Palæotherium. Anchitherium was an American form closely allied to the strictly European Palæotherida.

Rhinocerotida are at present found in Africa and South Asia only; they belong to three types, the African twohorned, non-scutellated; the Asiatic two-horned, and the Asiatic single-horned. The extinct members were numerous; four species existed in England. They did not

APIRIDE. The geographical distribution of the exist-appear before the Miocene epoch; many are found in ing members of this small order is very peculiar, they being confined to the Malay Peninsula, Sumatra, and most of South America. Lund has found their remains in the Post-pleistocene caves of Brazil; they have also been

America, but not above the Pliocene period. The exist ing genera have peculiarities in their incisor dentition; these teeth are quite absent in the African, and two above as well as below in the Indian species; when they are

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