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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

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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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 2007. could be raised shortly, it would enable the Finance Committee to authorise the call of the second 1,000l.; 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.

N 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 Nebula.-1, 2, 3, lines observed. Above, the solar spectrum is shown from 6 to 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

[graphic]

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

and dis'inctly 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 nebulae 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

we meet with in our laboratories, and again by assuming an absorbing medium in space. But after Dr. Franklani 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 nebula, 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

408

NATURE

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. extremely bright nucleus; then a kind of semilune of We have, first of all, an 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. comets he examined, the head gave out a light which very He found that in the 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. contrary, we got a bright line spectrum we should know we were dealing with a gas or vapour. If, on the as the light is red, the chances were that they were not You also see that, 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
LECTURES XIII. XIV. XV.

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

[Mar. 27, 1873

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

they were first found at Montmartre and worked out by
Cuvier; since that time they have been obtained from
The Palæotherida occur in the Upper Eocene only,
mouth, in the Isle of Wight, and in Hampshire. Several
many parts of France, the Bembridge clay, near Yar-
general aspect they must have been tapir-like. The
genera have been separated off, and about a dozen species,
from the size of a small rhinoceros downwards. In
orbital and temporal fossæ were also united, and there
maxilla curved downwards in front as in the tapirs; the
were large anterior osseous nares; the feet were much
like those of the tapir, though they were more specialised
than in the tapirs; the first pre-molar was rather rudi-
in wanting the fifth toe to the manus.
mentary, the others formed a uniform series with the
four teeth were present; the incisors were more uniform
The typical forty-
molars, which were wider than from before backwards,
be shown to have been developed on the type of Lophi-
odon, the outer wall bulging inwards, opposite the outer
much pressed together, and with short crowns.
of the lunate type of tooth; the transverse ridges were
They can
normal, and the internal cusps were slightly cut off from
cusps, instead of outwards, giving the earliest indication
semilunes. The lower teeth presented a peculiarity here
first noticed, each being formed by a double crescent,
them, turning backwards as the rudiments of the posterior
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. Palaplo-
Owen from Hordle. In the upper jaw the first premolar
therium was a smaller and earlier genus described by
the others were comparatively simple. The remains are
very abundant, the feet were as in Palæotherium. Gervais
was missing, and the corresponding lower one soon lost;
another early form, intermediate between Lophiodon and
has given the name Propalæotherium to a few teeth of
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 nuAmerica, but not above the Pliocene period. The existmerous; four species existed in England. They did not ing genera have peculiarities in their incisor dentition; appear before the Miocene epoch; many are found in these teeth are quite absent in the African, and two above as well as below in the Indian species; when they are

present the outer upper and the inner lower are rudimentary. The canines are absent in all; the full complement of molars are present, of similar character, and degenerating at either end; they are formed on the Lophiodon type; the outer wall is very strong and oblique, with the cusps but litle developed and the cingulum large behind; the posterior transverse ridge sends forward a process from near its middle, which in one fossil species (R. tichorhinus) is met by another from the anterior wall to form a circular foramen behind the anterior fossa. The lower molars agree with those of Palæotherium, being formed of a double crescent, in which the posterior cornu of the front lunule is partially overlapped by the anterior cornu of the hind one; no third crescent is found on the last molar; three toes are present on all the limbs. They have not been found fossil in the Eocene strata, consequently the American species are among the earliest. Leidy has named an allied genus of small size Hyracodon. Its teeth resembled rhinoceros, but the anterior premolars were retained; the peculiar uncus on the posterior transverse ridge was wanting, and the proportions of the incisors were reversed. There are several extinct species of the genus Rhinoceros. Acerotherium possessed the same number of teeth as the Asiatic genera, but the nasal bones were small, slender, and smooth above, so they could scarcely have carried a horn; it is a Miocene form only; a fifth rudimentary toe was present. Except R. pleuroceros, which had two laterally-placed tubercles on the nasal bones, all the other species had them melian. They may be divided by their incisors, as are the recent genera, some having them rudimentary, others not. All the European specimens had two horns, with or without functional incisors. The English species, which are not peculiar, are from Pliocene and Pleistocene formations; in R. leptorhinus the nasal septum was not ossified; in others it was much so, as in R. tichorhinus, a species which has been found preserved by ice in the river Vilni, a branch of the Lena, in Siberia; it possessed a hairy coat and the peculiar pit in the molars mentioned above.

From Port St. Julian, in Patagonia, Mr. Darwin first obtained bones of the peculiar genus Macrauchenia, which has not been found out of South America, and only in the Pleistocene deposits there. Prof. Huxley has proved the existence of a second smaller species from some fragments out of a copper mine in Bolivia. Owen showed in his, the first description of the animal, that the vertebræ were peculiar, and agreed with those of the Camels in having the vertebral artery threading a bony canal inside the spinal column, instead of through the bases of the transverse processes. It may be remarked that Myrmecophaga exhibits a similar conformation. But these vertebræ in Macrauchenia are further peculiar in having both ends of the centra quite flat instead of their being opisthocœlous, as in the allied forms. M. Bravard, who was killed in the earthquake at Mendoza, left excellent drawings of the skull and other parts of this animal, which Prof. Burmeister has since published. From them we learn that the skull was not unhorselike; the orbital ring was complete; the palate was not fully ossified between the posterior molars (the camels present the same peculiarity, though Artiodactylate); the nasal bones were extremely reduced, so that the anterior nares were directly above the posterior, and the lower jaw had the angle prolonged. Burmeister thinks, and with good reason, that the animal possessed a fair-sized trunk. There were twenty-four dorso-lumbar vertebræ, of which seventeen were dorsal. The radius and ulna, as well as the tibia and fibula, were fused throughout. The femur possessed an extremely small third trochanter; and there were three toes to each limb. The astragalus was strongly Perissodactylate, no cuboid facet being present. Our knowledge of the teeth is somewhat deficient, as they are always preserved in a much worn state. The typical

forty-four were present; the incisors were equine, and the canines of the same size; the back molars were the bigger and the anterior premolars comparatively simple. The lower molars formed double crescents, as in Palæotherium.

In tracing back the descent of the Equidæ, the Palæotherium d'Orleans of Cuvier has been shown to be generically different, and has been ca led Anchitherium; it is also found in Nebraska. These were small horse-like animals with teeth much as in Palæotherium, forty-four in number; the first premolars were very small, and no pit was present in the incisors; the outer wall of each molar was also concave opposite the cusps; the lower molars formed double crescents, and the last possessed the extra lobe. The ulna and fibula were fused with the radius and tibia respectively; the astragalus had some of the obliqueness of that of the horse, which it resembled in many other points. But there were three toes on the limbs, the lateral ones being less strong than the median. A peculiar antorbital fossa was present.

The horse must be described before the affinities of its close allies can be realised. In it the incisors possess the well-known pit; the canines are rudimentary in the mare; the premolars resemble the molars, and the crowns are very long and deeply embedded, with a concave crescent opposite the tubercles on the outer wall and the anterior internal tubercle insulated at first; otherwise they are typical. The depressions are very deep and are filled up by cementum, to form a solid mass. The lower molars are slightly complicated double crescents. The ulna and fibula are not free. Hipparion had very horse-like teeth. It is a later Miocene form, and is common in the New and Old World. It possessed the antorbital pit, as in Anchitherium, but was otherwise very equine. The canines were present in both sexes of equal size, and the anterior internal tubercle of the molars was completely insulated. The medi n of the three digits alone was functional. Merychippus, a Pliocene form, recognised by Leidy from some teeth, seems to have been an intermediate form between these and Anchitherium. Fossil true horses abound in America as well as the Old World; they since became extinct in the former locality. They are found in the Pleistocene nearly everywhere; their earliest remains are from the Sevalik Hills.

With these animals the description of the fossil Perissodactylata terminates.

PERCEPTION IN THE LOWER ANIMALS

LETTERS on this interesting subject still continue to pour in upon us in so great abundance that limited space compels us to select merely the facts contained in each. The best service we can at present render to the unravelling of the, we think, yet unsolved problem is simply to accumulate facts; no doubt a satisfactory explanation will by-and-by be arrived at. First we must give place to Prof. Croom Robertson, who thus writes as to the theory broached in his former letter :

In my former letter I made no pretension to explain all the wonderful feats reported of dogs or other animals, but only argued, in the wake of Mr. Wallace, that it had never been sufficiently considered what help in finding their way dogs might have from smell alone. Be the help what it may in the particular cases, I thought it clear that, if in their common experience smell does not somehow supply to dogs the defect of touch, they are, as far as we can see, badly fitted out, by comparison with men, for making their way through the world. And, even after your article of last week, I must still in their interest hope that the notion of a continuous world of smells is not an impossible one.

If the external world were the same to dogs that it is to mena complex of interwoven touches and sights in space, and only in addition dogs had more frequent and varied experiences of smell, the dying away or shifting of some in a particular train of odours would doubtless, as the writer of the article urges, put a dog out

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