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Africa, presented by Mr. B. B. Weil; two Jackdaws (Corvus monedula, white var.) British, presented by Mr. Harding Cox, F.Z.S.; eighteen Deadly Snakes (Trigonocephalus atrox) from Demerara, presented by Mr. J. J. Quelch, C. M.Z.S.; a Common Chameleon (Chamaleon vulgaris) from North Africa, presented by Mr. J. Pettitt; a Blue and Yellow Macaw (Ara ararauna) from South America, deposited; four Lapland Buntings (Calcarius lapponicus), twelve Snow Buntings (Plectrophanes nivalis) European, six Cirl Buntings (Emberiza cirlus) British, purchased.

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instrument. For a Auriga, with a comparison of 30 lines, the velocity was + 43'5 km. 8 Auriga is a spectroscopic doub!. with velocities, on February 5, of 84 km. and + 97 k Venus, on April 12, had an actual velocity of 13:55 km. The indicated by the negative was 15 km.

"HIMMEL UND ERDE" FOR NOVEMBER. -The current articles of interest. number of Himmel und Erde contains many astronomica. "The Heat in August, 1892" is the subject of an article by Prof. W. J. van Bebber. In this he bring together all the statistics of the temperature readings during the interval between August 11 and 25, and shows by weather charts the general state of the weather, such as wind, barameter, &c. The following few values, showing the highes temperatures recorded and extracted from the table mentioned above, may be of interest :

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App. Decl.

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+ 38 19 25.8

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+ 38 19 45

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734 Karlsruhe

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13 On November 9 the comet was a large and bright nebulosity, perfectly round, and 5'5 in diameter. It showed a central diffused nucleus, 10" in diameter. A rather brighter portion of an approximately elliptic form appeared to extend from the nucleus in the direction = 127°, its axes being 1'5 and 30" respectively. On November 13 the comet was only seen intermittently. It was 8' in diameter and nearly round. The nucleus no longer occupied the centre, but had shifted towards the preceding portion. The elliptical region was 2' by 30", and in the direction p116° 8. To the naked eye it was easily visible, being as bright as the Andromeda nebula near it, but less easily distinguished, owing to its smaller apparent size.

The most recent elements and ephemeris have been obtained from observations made on November 9 at Karlsruhe, November 10 at Rome, and November 11 at Göttingen, and are given in Astronomiche Nachrichten, No. 3128, from which we make the following extract :

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The comet can be easily picked up with a small telescope by knowing that it lies in a line joining the stars 8 and 0 Andromedæ, about one-third of the distance from B.

MOTION IN THE LINE OF SIGHT.-The transformation of the great reflector of the Paris Observatory for the purpose of adapting it to the spectroscopic determination of radial velocities is described by M. H. Deslandres (Comptes rendus 20). Instead of having a flat mirror at 45°, a collimator was placed in the optic axis itself, and movable along it. The rest of the spectroscope, which contained three flint prisms and a camera, was enclosed in a rigid steel box attached to the upper ring of the telescope. In order to control the motion, the plates forming the slit were made of polished steel and slightly inclined, so as to throw an image of the sky down into an auxiliary telescope inside the tube, which was provided with a reflecting eye-piece. Thus the observer below, standing near the great mirror, was enabled to keep the star well on the slit. With this arrangement, spectra of stars down to the 4th magnitude could be obtained, 12 cm. long, in two hours. In the blue portion a displacement of o'005 mm. indicated a velocity of 3'6 km. per second. The lines whose displacements were measured were those of hydrogen, calcium, and iron. 250 stars are within reach of the

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Dr. J. Scheiner, on "Astronomy of the Invisible," deals with the discovery of the dark companions of Sirius and Procyon. He commences with an historical sketch of the study of the proper motions of the fixed stars and leads up to the most modern observations describing the results obtained with regard to Sirius and Procyon. Prof. Barnard, with the help of twa excellent woodcuts, explains the working of the great Lick refractor. To prepare the instrument for micrometric work, be says five minutes is required; but for photographic work tes minutes is necessary, as a photographic correcting lens has to be adjusted to compensate for the difference between the photographic and optical focus; the large spectroscope absorbs nearly half an hour's work before it is ready for observation.

OBSERVATIONS OF PERSEIDS.-During the August display of the Perseids it has been noticed that in addition to the principal radiant point several minor ones have been observed which although not very far distant from the primary one, are still far enough to suggest that they belong to another swarm v. particles following a different track in space. The orbit, which the particles in the main follow, corresponds, as is well know, to that of the comet of 1862 III., and M. Bredikhine has sig gested that the particles producing these minor radiant potri belong really to the same swarm, only have either been acted o by external forces such as the perturbations of the major placets or have been projected from the comet itself at differe". periods.

With the intention of bringing some facts to bear upon th idea, M. Puiseux, in the Bulletin Astronomique for October. gives the results of his observations made in August of last year. which seem to confirm those of M. Bredikhine in sever points of view.

His method of observation was simply to chart down on large celestial globe the positions of the trails as observed. A glance at this globe, after 199 positions had been so recorded indicated that the area of radiation occupied a consider able surface, and extended principally in the directions of rig ascensions, that several distinct centres of concentration we observable, and that the same radiant points, in general, mas fested their activity at the same time, i.e., on the evenings August 10, 11, and 12, and some on August 7. In the ta accompanying this paper M. Puiseux shows that no less t fourteen different centres of radiation were observed. Table !! which we produce here, contains the essence of the whole wor and shows the positions of the radiant points in question together with the corresponding elements of the orbits deduce It must be remembered of course that their values cannot be very accurate, owing to the difficulty of observation, but th results are nevertheless interesting. The different radian points are denoted by A, B, C, &c., while a and & repress.

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journey exceedingly well. My men are all with me, except two left at Kuka." This is the most important journey through the Central Sudan and Sahara since the classical explorations of Barth and Rohlfs.




230 2





THE Royal Geographical Society has determined on a change n the form and alteration in the title of its Proceedings, which vill materially enhance the value of the monthly publication. The size of each part will be increased to ninety-six pages, and wo volumes will be published in the year instead of one as fornerly. Internally the arrangement will be slightly altered, and while the strictly geographical character of the publication will be maintained, the notes and record of geographical work from ther countries will be made at once more systematic and more Popular. A special feature will be the record of the "Georaphical Literature" of the month, summarizing all the ccessions to the library, both books and memoirs. This will orm a subject-index to geographical literature, and serve as a ontinuous appendix to the exhaustive subject-catalogue of the ociety's library which is now being compiled. The editorship f the new series remains in the hands of Mr. J. Scott Keltie, he assistant secretary.

WITH reference to the note on the death of Lieutenant chwatka, the Alaskan explorer, published last week, we are lad to observe that an official enquiry negatived the theory of uicide, and showed that the fatal result followed from an overose of morphia taken medicinally.

THE German colonial authorities have recently come to a ery important decision as to the official spelling of the place ames of their various protectorates in Africa and New Guinea. uropean names are to retain their ordinary form, but all native ames are to be rendered phonetically according to a new set of iles. These rules so closely resemble those put forward by the oyal Geographical Society, and now widely used, that it apears possible by some slight concessions on both sides to make ne set serve both for English and German. The letters c, q, x, dz are dispensed with as redundant, c and 2 being rendered ts, x by ks, and 9 by kw. The gutteral ch becomes kh, the nglish ch being given as tsh, and the sound of the English jas The German j sound will be represented by y, and the tter j used only for the French sound, which is represented in glish as zh. The German sound of w is rendered as v, the ter w being kept for the English sound. Unfortunately the ter s is kept for its soft German sound, the sharp sound of the glish letter being shown by 3. The use of the English uld have overcome this difficulty, and removed the most serious stacle to a common orthography.

CAPTAIN MONTEIL, whose arrival at Kano on his way to ke Chad was referred to in May last (vol. xlvi. p. 110), has last been heard of, and his mission, although involving two ars of travel in the Sudan and Sahara, appears to be successy completed. The facts could not be put more concisely than Monteil's official telegram to the French Foreign Office, which ved on November 15:-" October 17. To-day I entered territory of Fezzan by way of Tejerri coming from ka. Having set out from Kano on February 19, reached Kuka on April 10, where the reception was ellent. I left Kuka on August 15 with a guide, sent by Sheikh to accompany me to Murzuk which I expect

each on or about the 25th, and to stay there just long enough rrange my departure for Tripoli. Badaire has borne the


STROMBOLI is one of the most noted but least studied of volcanoes. The regularity of the weak explosions which, succeeding each other at intervals of a few minutes, characterize its normal state, gives rise to the idea that its action is always thus uniform and monotonous, and the occasional paroxysms to which it is subject are apt to be overlooked. In reality the socalled Strombolian phase of volcanic activity differs from the Plinian phase exhibited by Vesuvius and certain other volcanoes merely by the absence of intervals of perfect repose between the violent outbursts which are characteristic of the latter type. It is in this difference that the explanation of the fact is to be found, that from time immemorial no explosion in any way comparable to the great explosions of Vesuvius have occurred at Stromboli; for the ceaseless activity of the latter prevents the accumulation of sufficient force to produce a powerful and destructive effect. But from time to time the throat of the volcano does get more or less choked, and the efforts of the imprisoned vapour to escape result in an eruptive phase of some violence. Such an event took place during the latter months of last year, and the following description of the phenomena is based on the observations of Profs. Ricco and Mercalli, and of Ing. Arcidiacono.

The state of the volcano preceding this outburst had been one of relative calm for two years. In October, 1888, an explosion had opened three new mouths on the upper edge of the Sciara del Fuoco, from one of which lava was emitted. This was the commencement of a period of increased activity, with repeated issue of lava, lasting nine months till June, 1889. From this date to the eruption of last year, and particularly during the six months just preceding, the activity was less than normal. It is to be noticed, however, that there were two short intervals of recrudescence, lasting only a few days, at the end of December, 1890, and January, 1891.

On June 24, 1891, at 12.45 p.m., two strong earthquake shocks were felt over the whole island at an interval of a few seconds. Loud rumblings and a violent explosion followed each. The hocks were not confined to the island of Stromboli, but were felt at Salina, a distance of 40 kilometres. Even the subterranean rumblings were heard at the latter island. The first shock and the first explosion were, as might be expected, more violent than any which succeeded. Windows were broken at the semaphore station, and a great precipice of rock fell into the sea at the Filo del Cane, and other rocks in the same locality were so loosened that they fell on following days. Two powerful columns of ash, like thick smoke, arose from the crater and ascended far above the summit of the island. Great masses of scoria were ejected and fell toward the northern part of the island, burning the grass and fig-trees. A boat passing to the north-east of the island at the time of the first explosion could not see the semaphore signals, owing to the quantity of ash in the atmosphere. Lapilli fell around the eruptive mouths for a radius of a kilometre and a half, and a fine, dark grey ash rained over the whole island. A stream of lava issued from a point on the Sciara del Fuoco near to the most western mouth, and a deep fissure formed its upper rim nearly in the same place as that of November, 1882. For two days the lava continued to flow, and loud explosions were frequent. The rumblings were almost continuous. On the 26th the emission of ash ceased, but moderately vigorous outbursts occurred with the ejection of incandescent scoria till the 27th; but on the 28th and 29th the volcano had resumed its wonted calm. On the 30th, however, a fresh earthquake, accompanied by rumblings and a violent explosion, showed that the volcanic forces were not yet spent. An immense column of vapour and incandescent materials arose from a new breach on the edge of the Sciara, while an abundant current of lava flowed down the slope reaching the sea at its foot. The whole of the powerful explosions o the 30th were repeated at short intervals, but the activity

Sopra il Periodo eruttivo dello Stromboli cominciato il 24 giugno, 1891. Relazione dei Prof. A. Ricco e G. Mercalli col Appendice dell' Ingegnere Arcidiacono ("Annali dell' Ufficio Centrali Meteorologico e Geodinamico' [2] XI. Pt. 3, 1892)

gradually declined til July 4, when its normal state was reached. The eruptions were again violent, with emission of lava from the 16th to the 23rd of July.

The mouths on the edge of the Sciara, which were contemporaneously active during the above period, were four in number-two at the northern end and two at the western end. One of the former pair was opened by the explosion of June 30, and from it was ejected the greater part of the detrital material of the eruption, so that around it a cone has been built up, truncated by a crater, sub-elliptic in form, of about 60 metres in maximum diameter. The height of this new cone above the old edge of the Sciara is about 50 metres. The other crater is situated on the deep fissure mentioned above, and at night, from the sea the incandescent lava could be seen in free communication with the atmosphere-a circumstance which explains the fact that the explosions from this crater were rare and of feeble intensity. The two western ones were situated one below the other with an interval of about 30 metres. Near the lowest, three large fumaroles gave forth dense columns of steam, while other lesser fumaroles were plentifully scattered about. The majority of the explosions took place from these two mouths. During this same period, lava was emitted three times, (1) on June 24, soon after the first two explosions from the most western part of the Sciara; (2) on June 30, from the crater on the fissure; (3) on July 16, from the central part of the Sciara, between the first two. They all reached the sea, and since the second stream doubled itself round an obstacle about half way in its course, four new points were formed on the shore. The thickness of the lava at these points varied from 4 to 6 metres. Specimens of the lava collected from the most western stream showed that it consisted of an almost homogeneous blackish-brown paste, compact in the interior, but becoming more and more porous and reddish in colour towards the exterior. Some of the larger cavities were internally covered with a shining brown patina. Externally it was covered with a rough crust, reddish-brown in colour, and of scoriaceous aspect. It was sensibly attracted by the magnet, and melted without effervescence to a brownishgreen glass. Crystals of plagioclase, augite and olivine were apparent. In section, about two-thirds was rendered opaque and black by very minute microlitic granules of magnetite which were intimately mixed with a transparent glassy base, colourless or inclining to greenish. The remaining third consisted of a great number of colourless transparent microlites of plagioclase. Fluidal structure was only just apparent. In this microlitic paste were scattered crystals of plagioclase, augite, and olivine. The augites were greenish in section and possessed a feeble pleochroism. The olivines were corroded and irregularly fractured.

Analysis gave the following numbers :

Manganous oxide

Etna. Mean of analyses of 20 modern lavas.

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49'45 19.30

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The lava is similar to other lavas of Stromboli, and to show the great similarity between the lavas of Stromboli and Etna, the mean of the numbers of twenty analyses of modern Etna lavas is appended for comparison.

The scoria, lapilli, and ash of the eruption present no special features, but are what might be expected from a lava of the above composition.


Although the volcano had reached a state of comparative calm at the end of July, this did not last for very long. Towards the end of August fresh signs of activity gave warning of an approaching explosion, which took place on August 31. was preceded by an earthquake a few seconds before, and as a result a vast column of ash rose above the volcano, while scoria and other projectiles were shot out to a considerable distance. Soon after, a fine ash, dark red in colour (instead of black as in

June-July), fell over the island, covering the ground in s places to a depth of several centimetres. On the evening September 1 dense columns of ash were again emitted, and the afternoon of September 3 the whole crater was envelope in a thick mantle of steam, in the midst of which could be di seen a reddish-grey column of ash rising with extraordinar violence to a great height, when it spread out into a vola "pine." A fresh stream of lava was also observed. Erupti succeeded each other at short intervals, accompanied by cr tinuous rumblings, interrupted now and again by loud ex sions, like heavy artillery. As far as could be observed, on western side of the crater was a single mouth of almost cire.. form, 10 metres in diameter, which was most active in serin up vast columns of ash and projectiles of all kinds. To the e could be seen one or more little mouths, which trang emitted large volumes of steam, while in the midst a larg aperture, 30 metres in diameter, irregular in form and dee fissured, was in powerful action. The activity, however, gra ally quieted down, and towards the end of the year th volcano resumed its normal state.

In conclusion, it is useful to compare this eruptive phase Stromboli with other contemporaneous seismo-volcanic nomena of the Italian peninsula. It appears that earthquis occurred in various districts in the early months of IS especially one on June 7 in the Verona district, rather severe, casioning loss of life. Vesuvius was rather more active :) usual during the whole of June, and in correspondence with t the great fumarole of the solfatara at Pozzuoli, increased in te perature. It is particularly interesting to note that Vulcan the other active volcano of the Lipari Islands, remained in pe fect calm during the whole period, emitting only vapour re the fumaroles. As, however, the character of the eruptions the lithological composition of the material ejected from t volcano differ so greatly from those of Stromboli, it is tolerab certain that there is no free and direct communication betwes the reservoirs of these two volcanoes. In fact, Stromboli pre sents a much greater analogy with Etna. The similarity of th lithological composition of the lavas of these two volcances t already been referred to, and, further, Prof. Mercalli obser that the last four or five eruptions of Etna have all been inc diately preceded or followed by a paroxysm at Stromboli. is thus possible that there is a real relation between them. L. W. FULCHES




the Mineralogical Magazine and Journal of the Miss logical Society of July, 1887 (vol. vii.) Mr. L. Fletche M.A., F.R.S., president of the Society, describes four spe: mens of a new meteoric iron found at Youndegin in Wer Australia. They were discovered about three-quarters of a E to the north-west from the top of Penkarring Rock, in the ab* district, about seventy miles from York. These fragments w found by Alfred Eaton, a mounted police constable, when duty in the district of Youndegin, when he brought in one of Mr. Fletcher s four pieces he found on January 5, 1884. that the late Mr. Edward T. Hardman, F.G. S., the he Government geologist, expressed his belief in the meteoric of these iron masses. Later the above-named Alfred Eaton sent with a native assistant with instructions to bring other three pieces, and at the same time an unsuccessful se was made for additional fragments. In the above account stated that the four pieces were lying loose on the surface, of them close together, and the fourth fifteen feet away. weighed respectively 25 lbs., 24 lbs., 174 lbs., and 6 lbs.. largest and smallest fragments are now in the British Mas collection, and the specimen of 24 lbs. is in the Geoly Museum at Freemantle, and the fourth piece, weighing 171** was presented to the Melbourne Museum in Victoria.

The new specimen now in my possession was discovere year, and weighs 3824 lbs., and measures 22 inches 20 inches wide, and 13 inches in its greatest thickness form it is roughly convex on one side and concave on the on both sides of which are large depressions or pittings sin to those usually observed on other large masses of meteoric It is somewhat triangular in outline, but with irregular s It has one small hole quite through the mass near the top, numerous deep holes, one near the bottom left-hand c

ng a diameter of about 1 inches and 4 inches deep; another he opposite bottom corner 2 inches deep and 2 inches in meter; also another of 3 inches deep, and several others. the upper edge especially, and at several other parts near, on the edges, are fractured surfaces, as if in its fall a mass passes were broken off, leaving a coarse crystalline structure, which would indicate that several other large holes having sted before its fall on the earth, probably all or most of the ces were connected together, and might have fallen in one s. It would be interesting to know if any of the pieces ed together at the fractured surfaces as seems to me might be

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possible. I observe that the two specimens of this iron in the British Museum collection exhibit similar fractures on the edges. Before receiving this specimen I was informed that two masses were found, but have no information at present as to the size and weight of the other.

Mr. Fletcher in his paper minutely describes the size and form of the two British Museum specimens, and that the specific quantity was determined from three small pieces from the larger specimen, and gave 7.86, 7.85, and 7'72. He also states that a portion was cut off the larger piece by means of hack-saws, and was found to be so hard that three weeks were required to

The Youndegin iron was also remarkable in containing the minute cubic and modified cubic crystals, having metallic lustre and of a greyish black colour, and which were determined to be graphitic in character, but of a diamond-like form; but were later found to be still distinct from the diamond, but having somewhat more the features of graphite. Mr. Fletcher therefore decided to give the name of Cliftonite to this substance, as being a new form of a carbon mineral. A most exhaustive description of this new mineral is given in his paper. Similar crystals of this substance are found in one or two other meteoric irons.

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THE CROSS-STRIPING OF MUSCLE. PROF. RICHARD EWALD of Strassburg, has just communicated a paper to the fifty-second volume of the Archiv. f. d. ges. Physiol., in which he confirms Prof. Haycraft's views concerning the structure of striped muscle. The latter observer has held for many years that muscle fibrils are varicose threads, and that the cross-striping is but an optical appearance due to this varicosity. The varicosity is often difficult to den.onstrate in the ordinary way, and most histologists were not prepared to admit that the stripings are all and entirely due to it. Prof. Haycraft, however, recently brought forward to the Royal Society of London, and to the Berlin International Medical Congress, fresh and striking proof of the strength of his position, by demonstrating films of moist collodion, on which pieces of muscle had been pressed and then withdrawn. As a result of this pressure the collodion films were stamped as with a seal, and the impressions revealed in striking detail every stripe of the original fibre. Prof. Ewald confirms these experiments in the fullest manner, but suggests that the collodion impressions might be produced on the assumption that there are layers of hard and soft material alternating with each other in the course of the fibrils. In this case the hard material would press into the collodion and make a series of furrows, which would appear as a series of stripes when examined with the microscope. Prof. Haycraft had previously demonstrated the varicosity of the fibrils, seen by transmitted light, and had published photographs of his preparations, but Prof. Ewald was still sceptical upon this particular point, and sought to assure himself still more conclusively. With this end in view he examined muscle, which had been rendered quite opaque, by means of reflected light, for under these circumstances the influence of the internal structure would be entirely set on one side, and the surface of the fibrils would alone receive and reflect the illuminating rays. For purposes of illumination Prof. Ewald used the apparatus of W. and H. Seibert, of Wetzler, by means of which vertical rays can be projected upon an opaque object; and he rendered his preparations, both of fresh and of hardened muscle, quite opaque by a method of over-silvering. Under these conditions Prof. E ald found that the cross-striping is most distinct, and he was able, with his admirable method of illumination, to examine the surface of a muscle just as one may observe the surface of the country at night by means of a search-light from an observatory. With the light perfectly vertical the tops of the ridges of the muscle are bright, and the valleys on either side in half-light. By shifting the light to one side or to another the slopes of the ridges can be thrown alternately into shadow or bright light. Prof. Ewald concludes by admitting that his experiments fully prove that the striping is due to the shape of the fibrils alone, and that the internal structure of the muscle plays no part in its production.


N taking a general survey of colcured objects, whether

ΟΝ natural or artificial, we become aware of the fact that

whilst the colours of some remain unchanged as regards tint, whatever their position in relation to the incident light, the tint of others varies with every alteration in their relationship to such light source. We thus see that so far as their colours

1 By Alex. Hodgkinson, M. B., B.Sc. Reprinted from the fifth volume of the -fourth series of "Memoirs and Proceedings of the Manchester Literary and Philosophical Society." Session 1891-92.

Of objec

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are concerned all bodies may be arranged in two grem according as their colours change or do not change in inte Nor is t their angular relationship to the light varies. classification entirely an artificial one, since, as will shortly seen, though this change in tint with variation in the source is an essential difference, it is not the only differete even in the colour manifestations of the two groups, for also characteristic of the nature of the colour producing struct It is to the above-mentioned varying colours that we apply term iridescent, from the resemblance they bave in the sequen or play of colours to the tints of the rainbow. The unvay group of colours, having no equivalent term to "iridescence" express the nature of their colour production, are spoker as "pigmentary," or absorption colours. In naming exampl of objects, natural and artificial, grouped as above in accorda with the nature of their colours, it is difficult to make a select where all are so varied and characteristic. I have preter therefore to cite only such instances as I myself possess, 2 am therefore able to show you. As examples of pigmentas colours, I need only name one or two for the sake of comparis since the colours of most objects ordinarily met with are mentary. Leaves, flowers, dyes, birds, fish, insects, mineras &c., exhibit these colours, some almost entirely, and excepting fish, in far the majority of instances. displaying iridescent colours we have also examples in th various divisions of the animal, vegetable, and MIDA kingdoms. Amongst birds the most striking examples & found amongst the humming birds, sun birds, birds paradise, &c. Insects, again, furnish numerous example more especially amongst tropical species, though not, perha proportionally in greater numbers than amongst those belong to our own more temperate regions. The colours of fish = almost entirely iridescent, since their very whiteness, or sve sheen, is due to the admixture of the iridescent colours innumera le minute thin lamellæ, too small to be seen indivi ally with the naked eye, but plainly perceptible under t microscope. In the vegetable kingdom iridescent colours far more numerous than is ordinarily recognized, the surfaces of the cell walls produce interference colours wh are more or less obscured by the pigmentary colours of leas and coloured flowers, but may be readily seen in the case white flowers by the aid of a lens and sunlight. Under the conditions each cell may be seen to sparkle with its c iridescent colour, forming, by admixture of the interferer tints of neighbouring cells, the varying shades of white see numerous flowers which are devoid of pigmentary co Mineral bodies displaying iridescent colours are also numerce opals, sunstone, fire-marble, felspar, mica films, tarnish various metallic crystals, certain crystals of chlorate of pots &c., are examples.

In describing the various natural objects for purposes identification, or mere description, no account can be conside complete which omits ail reference to their colours, and especially is this the case where the colours constitute sach striking feature, as in the case of iridescent bodies. In in erable instances, more especially amongst birds and lase their specific names are taken from some conspicuous cu they possess. It thus becomes evident that a correct desc tion of the colours of bodies is of importance, and where e colours are of the pigmentary, or unchanging kind, this i matter of no difficul y. How different, however, in the of objects, the colours of which not only vary with every cha of position, but disappear altogether, unless viewed with spe relation to the light source. Nor can it be wondered at: descriptions of these objects, even by observers of undre repute, vary according to the different angles from which t have been viewed; or are vague and profuse, owing to fra attempts to describe their changing tints produced by movement. The fact is, no words can convey an ade impression of the gorgeous effects produced by most of objects, whether birds, insects, or fish, when in mos brilliant sunshine. Some notion of the difficulties to con with in describing the colours of humming birds, for ex may be gathered from the remarks of Wallace in his wats Tropical Nature," when speaking of humming birds:some species they must be looked at from above, in others below; in some from the front, in others from behind, in to catch the full glow of the metallic lustre; hence, wher birds are seen in their native haunts, the colours come and change with their motion, so as to produce a startling

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