310

in his gracefully fluent yet finished style, and then come Blaserna's polariscopic experiments, clearly and energetically expressed, and, as far as I can judge, affording most conclusive results. It is not a little remarkable how much is contributed towards the value of the observations by the manner in which each observer relates them. The descriptions are given with such charming naïveté and absence of affectation, that the reader can appreciate almost the exact degree in which the writer's hand shook as he manipulated his instrument, not to speak of the degree in which his assertions can be relied upon for accuracy or freedom from bias.

NOTES

JOHN BRETT

M. JANSSEN has been elected a member of the Astronomical

SOME weeks ago we expressed a hope that the vacant Swiney Lectureship would not be given to one who is already well off, but to some well-qualified young man, who would thus have leisure to Our hope, we are glad perform work of high scientific value. to see, has been essentially fulfilled in the appointment of Dr. Carpenter, who, unusually young in spirit, assuredly deserves the leisure which this appointment will ultimately help to bring him, leisure which, we have good reason to believe, will be devoted to the completion of work of very high scientific value indeed. Few men have devoted gratuitously more of their time to the public benefit, and we believe that he accepts the appointment mainly in order that he may have a good opportunity of

42, against 13 for M. Loewy, and 1 for M. Wolff.

AT a recent meeting of the Natural Science Section of the Literary and Philosophical Society of Sheffield, a discussion took place on "The Attitude of the State to Science," in which Dr. Hime, Mr. Alfred H. Allen, Mr. H. C. Sorby, F.R.S., and Mr. J. Spear Parker successively took part, and the opinion of the meeting was embodied in the following resolution, which was passed unanimously:-"That this meeting deplores the supineness of the Government with respect to science, and believes that the national recognition of research, and the establishment of better means of rewarding discoverers, would be a direct benefit to the country."

In order to remove any apprehension that might arise in the minds of some members of the Anthropological Institute (particularly of those residing in the country), from statements made that, in consequence of the recent change in the composition of the Council, a preference would be given to papers of an ethnographical class over those relating to other branches of anthropology, the director, with the full concurrence of the president, has thought it advisable to assure the members of the Institute that no such result need be feared. Papers on every branch of anthropology will always be cordially received, provided they comply with the requirements demanded in all communications to a Scientific Society intended for publication, amongst which, a very essential one is, that they should contain either ". new facts or new applications of admitted facts." As a further assurance that all proper subjects will receive due and equal attention, it may be well to state in general terms what may be regarded as proper subjects to be brought before the Anthropological Institute. They may be included under the following heads :-(1) The Physical History of Man and of the Human Race; (2) Psychology; (3) Comparative Philology; (4) Priscan Archæology, a Prehistoric, Protohistoric; (5) Descriptive Ethnography, comprising the Reports of Travellers and Explorers on the Physical Characters, Derivation and Relation, Manners, Customs, Religion, Language, &c., of various Races or Nations; (6) Comparative Ethnography; (7) The Relations between Civilised Man and Aboriginal Savage Peoples. In this programme it will be seen that any subject properly coming under the cognizance of the anthropologist may find a place. And in order to insure confidence that each and every subject will receive due attention, it is suggested that committees might, if thought desirable, be formed of such members of the institute as may take a special interest in any of the above branches of inquiry, whose function would be, each in its own sphere, to promote

inquiries in which he has been engaged during the last few years. Dr. Carpenter, we understand, has had by him for years, the material, fully worked out, of important papers which he has had no time to produce. Dr. Carpenter has once before held the Swiney Lectureship, and it has been offered to him again without any solicitation on his part.

ON Monday last, in the first of his Hunterian lectures for this year, Prof. Flower drew special attention to the peculiarities of a new animal discovered by Prof. Marsh, of Yale College, and named by him Dinoceras mirabilis. This remarkable ungu alte, nearly the size of the elephant, was obtained from the Eocene beds of the Rocky Mountain region. It possessed osseous cores for three pairs of horns, which rise successively one above the other; a supra occipital crest is greatly developed, projecting obliquely backward beyond the condyles. The posterior pair of horns arise from this crest, the median from the maxillaries, and the anterior from the tips of the nasals. canines are greatly developed, and the upper incisors are wanting. The skull is unusually long and narrow, and carries six small molar and premolar teeth. The extremiues resembled very nearly those in the proboscidia, but were proportionately shorter. The femur possessed no third trochanter and no pit for the ligamentum teres. It therefore possesses characters allying it with the perissodactyles as well as scidia.

The

the pro

PROF. MARSH has also drawn attention to a new sub-class of fossil birds from the cretaceous shales of Kansas. The specimens, while possessing the scapular arch, wing, and leg-bones of the truly orthnithic type, present the very aberrant conditions of having biconcave vertebræ and well developed teeth in both jaws. These teeth are quite numerous and implanted in distinct sockets; the twenty in each ramus of the lower jaw are inclined backwards and resemble one another. The maxillary teeth are The sternum equally numerous and like those in the mandible. have a carina and elongated articulations for the coracoids. The lower of the posterior extremities resemble those of swimming birds. The last sacral vertebra is large, so it may have carried a tail. Professor Marsh proposes the name Odontornithes for the name of the new sub-class, and Ichthyonithes for the order to contain this remarkable species, which is about the size of a pigeon.

Ar a meeting of the Senate of the University of London held last week, a resolution was passed by a majority of two, that it is desirable to make Greek an optional subject at the Matriculation Examination. The practical effect of the carrying ou

of this regulation will be, that while those who are intending to proceed to degrees in Arts will continue to take Greek at the matriculation, as a matter of course, it will not be required from those who are going on to degrees in Science or Medicine.

MR. A. W. BENNETT, M.A., B. Sc., F.L.S., has been elected Lecturer in Botany at St. Thomas's Hospital School of Medicine, in the place of the Rev. J. W. Hicks. A vacancy is thus caused in the Lectureship on Botany at the Westminster Hospita School.

THE following new candidates for the Professorship of Geology at Cambridge are announced :—Mr. William King, Professor of Mineralogy and Geology, Queen's College, Galway; and Mr. P. Brodie, M.A., F.G.S., of Emmanuel College, and Vicar of Rowington.

THE office of Chief Assistant in the Observatory, Cape of Good Hope, will be filled up by open competition on March 18 next, and the following days. Candidates must be between eighteen and twenty-five years of age, and the salary commences at 320/., rising 10l. a year to 450/.

WE are really sorry to hear that the much-talked-of Arctic expedition of M. Pavy, who was recently fabled to have discovered an Arctic Continent, has vanished into worse than "thin air." It is perhaps unprecedented in the annals of science that the funds meant to be devoted to a noble and heroic purpose, should be literally wasted in riotous living. We hear, on too good authority, alas, that M. Pavy's explorations have been confined to certain not unknown phases of "life" in San Francisco.

COAL has been discovered on the railway from Mollendo to Arequipa in Peru. The seam is four yards thick. The coal has been reported as of good quality, and it is already being used on the railway.

DR. REISS, one of two German travellers in Ecuador, has succeeded not only in ascending Sotopax, but in entering the

M. DE FONVIELLE has been authorised by the French Academy to make a series of experiments on a new lightning conductor which he has devised.

THE Report of the Marlborough College Natural History Society for the half year ending Christmas, 1872, contains much that is of considerable interest and value, though we are sorry to see from the very honest preface, that the Society is not in so satisfactory a condition as it ought to and might be. While admitting that a fair amount of work has been done, the preface complains of the lack of interest in the work of the Society, of the members. With regard to nearly all the sections, and the comparatively small amount of energy displayed by many the tone of the preface is desponding, though hopeful that Society contains some excellent workers, who have shown no a change for the better may take place next year. The disposition to relax their efforts, and we earnestly hope that their example will be largely contagious, and that the next report will be written in a very different tone. It is a pity that a society so favourably situated in many respects as this is should not produce more abundant and more valuable results. The geological section, we are sorry to see, is nowhere, mainly for want of a permanent head. The society is also very much cramped for want of a suitable building for the museum. We hope this report will stimulate all the members to renewed activity; let them take to heart the very excellent advice given in the paper on "An Ideal School Natural History Society," by Mr. E. F. im Thurm, who deserves great praise for his efforts on behalf of the society. Appended are reports of the out-door work done in entomology and botany during the half year, and a long and very interesting paper by the Rev. J. A. Preston, describing what he saw on a recent visit to Brazil. The concluding article of the Report is Part I. of a carefully compiled descriptive Catalogue of the Archæological Collection of the Society, by Mr. F. E. Hulme, which is accompanied with a beautifully executed illustration of some of the articles in the collection.

AT the first meeting of the Sheffield Naturalists' Club held a few days ago, Mr. H. C. Sorby, the president, delivered a very excellent inaugural address, in which he gave his views as to the objects of the formation of such a society. Such a society as this, he said, had two characters. First of all, the subjective influence it had on the members who composed it. The study of natural history was most desirable in many ways. Man had a certain amount of energy; it must be expended in some way or other, and the examination into natural history furnished them with a study which was advantageous to both body and mind. By being joined together in a society they might greatly help one another. With regard to the objective value of such a society as this, he thought they ought not to limit their efforts to the mere making out of accurate lists of flora and fauna which

THE Times of India reports a sharp shock of earthquake which was felt on January 7, about 4 P.M., at the camp between Sultanpore and Fyzabad, in Oudh.

be devoted to the discovery of general philosophical principles, as applied to both animals and plants. He thought they could learn a great deal more by the careful study of the commonest things than by looking for rarities. They could not hesitate in saying that a great deal remained to be done in the study of

THE French authorities at Tahiti report in their official journal that, in consequence of changes in the coast line and reefs, new rules for navigation have been issued. They announce, also, that the island placed in 21° 50' S., and 152° 20′′ W., does not exist, as the place has been sailed over by three vessels. Captain Truxton, of the U.S. ship T. Jamestown, has informed them that he has passed over the position of a reef assigned to 24° 45′ S. and 150° 40′ W., without seeing any token of danger.

were some of the points which such a society should inquire into: -What is life, and how have the various species of animals and plants originated? Why do particular plants grow in particular localities? The determination of that question would have a most important bearing on geological theores. Another problem for study was what was the effect of dry or wet seasons on certain plants? If that question were settled, they might know the effect that must have been produced in bygone ages-by the alteration of climate-on certain plants and animals. Another most interesting subject for investigation was the influence of

plants on plants, animals on animals, and one on the other; the fertilisation of plants by insects, and the attractability of diffe

PROFESSOR RAMSAY ON LAKES

for study were the following:-The manner in which the habits of animals have been acquired; the manner in which varieties or species have been formed; the limit of the successive generation of insects through none but females; the diseases of plants due to parasitic fungi and insects.

THE first number of Petermann's Mittheilungen contains a brief account of the eruption of a new volcano in Chili, which occurred during part of last June and July. The volcano, known by the name of Lhagnell, is situated in the south of the country, in Arauco, between the volcanoes Villarico and Llaima, near the river Cautin. Immense quantities of sand seem to have been thrown out, some of which, according to Dr. Philippi, of Santiago, reached a distance of 300 or 400 miles north from the volcano. This sand is described as consisting of angular, transparent green particles of volcanic glass. Dr. Philippi also reports that for fourteen days, about midday, a strong south wind blew, as far north as Santiago, small quantities of sand, much coarser than the above, with rounded corners, opaque and grey. Great quantities of lava, according to the report of a spectator, have overflowed the district, causing considerable destruction to life, and stopping up the river Quepe, which is thus being converted into a considerable lake.

We have received a small pamphlet, by Mr. B. H. Babbage, containing a description of a portion of the late Mr. C. Babbage's calculating machine or difference engine, put together in 1833, and now being exhibited in the educational division of the South Kensington Museum.

La Revue Scientifique for February 15, gives a summary of the much needed administrative reforms which have been introduced into the Collège de France.

We have received the following papers recently read before the Eastbourne Natural History Society :-"On Geoglossum difforme or Earth-tongue," by Mr. C. J. Muller; "A Note on the Wall Pelletory," by Mr. F. C. S. Roper; “On the Planet Venus," by Mr. T. Ryle.

THE principal articles in the Quarterly Journal of Science are:- -"On the Probability of Error in Experimental Research," by Mr. Crookes; "Condition of the Moon's surface," by Mr. R. A. Proctor, with photograph; "Colours and their Relations," by Mr. Mungo Ponton; and "Remarks on the Present State of the Devonian Question," by Mr. H. B. Woodward.

THE Annual of the Royal School of Naval Architecture, &c., contains some good technical papers. This publication will become vastly increased in importance, and we hope in value, by the establishment of the new school at Greenwich.

WE take the following from the Engineer :-The question as to whether a gasometer will explode when fired was settled in Manchester on Tuesday, February 11, when one of the gasometers at the Manchester Corporation Gasworks in Rochdaleroad was destroyed by fire. The origin of the fire is not known, but about 2 o'clock a workman saw flames issuing from one end of the gasometers, and the flames could not be checked till the whole contents of the gasometer, about 600,000 cubic feet of gas, had been consumed. Many inhabitants of the neighbourhood hurried away with loads of their furniture, fearing an explosion, but nothing of the kind occurred.

ADVICES from Cyprus state that no rain had fallen on the island for months; but this is probably an exaggeration.

WE learn from the Athenæum that the Rev. Thomas Hincks, F.R.S., is now engaged in preparing a "History of the British Polyzoa."

:

I. FRESHWATER LAKES, THEIR ORIGIN AND GEOGRAPHICAL DISTRIBUTION

There are many classes of lakes in the world, formed in various ways, and though he had been unjustly charged with a scribing all lakes to one origin, he would be the last person to do so. He then went on to examine the various means which might be supposed to produce lake basins, and especially that class of lakes scattered over the whole northern hemisphere-in Wales, Cumberland, Scotland, Sweden and Norway, Russia. and N. America -the basins of which had evidently been formed by the erosion and grinding out of portions of the earth's crust. In many cases these lakes are in true rock basins, surrounded by lips of rock. How were these hollows produced by Nature? The dislocations of the earth's crust could not produce them; as a rule the sides of faults are close together or the fissure is filled up with other matter, and the depressions due to synclinal curves were never so simple or perfect as these lake basins, owing to violent disturbances, and to subsequent denudation. The theory of a special area of subsidence for each lake seems absurd, on considering the vast numbers of separate lakes, in N. America for example, lying in some case within a mile or two of each other. Again, a lake cannot make its own hollow; what little motion there is in the water can only affect the waste of the shores. Neither can a river scoop out a lake hollow, it can only produce a long narrow channel, and go on widening and deepening that, and the sediment which it carries down into the lake will in the long run fill up the lake basin. The action of the sea, too, on its shores cannot scoop out a lake hollow, it can merely wear back its cliffs and form a "plain of marine denudation "just below the level of its waters. And thus having exhausted all the other natural agencies which effect the denudation of the land, what agency remains to us to account for the formations of these lake basins, but the grinding power of ice? The lecturer then adverted to the phenomena of the formation and progress of glaciers, illustrating his remarks by diagrams of the great Rhone glacier. In the Alpine valleys there are numerous indications-in the mammellated surface of the rocks, the striation, moraines, and boulders-that at some period in the past all these glaciers had been very much more extensive than at present, and were found in many parts where now they are altogether wanting. In Greenland the whole country is covered by a universal ice sheet, which extends into the sea in some cases several miles, and where cliffs of ice rise out of the sea 200 to 300 ft. high, and, as recent soundings have shown, are sometimes 3,000 ft. deep. Large masses of these breaking off float away as icebergs, bearing with them stones and rubbish which they deposit, on melting, irregularly over the sea bottom. In the mountains of Wales and Scotland, in the Vosges, the Black Forest range, and in N. America are numerous signs of glacier action, all which prove that at one period, recent in a geological sense, glaciers were present in those districts; and boulders and boulder clay deposits show also that the Northern part of the Northern hemisphere was passing through a glacial epoch.

Boulder clay and moraines have sometimes dammed up a stream of water aud formed a lake, but lakes of that kind are neither numerous nor of much importance. The theory that the true rock basins were scooped out by glaciers first occurred to the lecturer whilst observing in N. Wales, and he applied it first to the explanation of the tarns about Snowdon, but exsubsequently of the American lakes, warranted him in applying tended observation of the Italian and other great lakes, and it to them also. He had especially applied it to the Lake of Geneva, which lies directly in the course of the old Rhone glacier. The lake is 983 ft. in depth in its deepest part, nearly in the centre. Where the glacier entered the lake it could not have been less than 3,000 ft. thick, and as the rock underneath is comparatively of a soft character, where the ice was thickest the grinding power was greatest, and it scooped out its deepest hollow; but towards the south end the mass had grown less through melting, and the result was a shallowing of the basin It is in the valleys of Switzerlan1 down which the glaciers must

formerly have extended that the lakes lie. The great depth of Lake Maggiore beneath the sea-level-2,300 ft.-is no argument against the theory, for a large mass of ice would block out the sea-waters. In Wales the lakes are never of large size, Lake Bala, the largest, being about 4 miles long; Lake Windermere lies in a true rock basin, as do many others in that district; in Scotland, where the climate was more severe, the lakes are larger and more numerous; in Sweden and Norway, in Finland and N. Russia the lakes are almost innumerable, while in N. America they are scattered almost broadcast over the country N. of lat. 43°. Where the glacial action was most intense, there the lakes become more and more numerous, and he believed they were due not to special glaciers, like those on the south side of the Alps, but to that great ice sheet which, according to Agassiz, covered the whole country. In South America and New Zealand, too, are signs of a similar action, and there too, lakes of this class occur. The present glaciers of New Zealand are very small compared with what they evidently were at a previous period, and in the course of every one of them are lakes, which, according to reports he had received, also lie in true

rock basins.

II. SALT WATER LAKES, THEIR ORIGIN AND GEOGRAPHICAL DISTRIBUTION

Rain-water

per

The lecturer said that he could not account for the origin of all salt-water lakes, but for some of them the evidence is clear, and it is plain to see why they are salt. The principal minerals forming the rocks of the earth's crust are silica, alumina, lime, potash, soda, magnesia, peroxide of iron, &c. takes up from the atmosphere and the earth's surface a small proportion of carbonic acid, and thus acquires the power of dissolving certain of these minerals as it percolates through the rocks, notably lime, which it carries away in the form of a bicarbonate. And thus the water of all springs is charged more or less with mineral ingredients, though these may be recognisable only by the skill of the chemist. Thus the water of the fountains in Trafalgar Square contain 69.75 grains of salts gallon, including chloride of sodium 25.7; bi-carbonate of soda 14.5; sulphate of soda 18 4. The Thames water at Teddington contains 22.5 grains per gallon, and thus carries to the sea in the course of a year 377,000 tons of salts; the old well at Bath holds 144 grains of salts per gallon, thus bringing to the surface 608 tons of salts per year. The apparently small quantity of bi-carbonate of lime in a per-centage of the salts of sea-water, is still sufficient to furnish to marine creatures materials for their shells and skeletons, and thus indirectly to build up the great beds of limestone which are now in course of formation, or belong to former geological periods. The analyses of salts in sea-water and in the water of various lakes is given in the following table:

Mediterranean Sea.

01304 0*0887

Per centage of Chloride of Sodium.....

2'9460

Black Sea. 1'4020

Sea of Caspian Azof. Sea. 09658 0 3673 0°0632

Calcium.....

Magnesium

0'2480

0'0764

O 1239

Bromide of Sodium

0*0558

Carbonate of Lime......

O'1470

0 0359 0'020)

1*7661

0'0171 0'0129 0'0013

1*1880 o'6294

Dead Sea. 12'110

7'822 2.455 1 217

0'452

24056

Salt lakes though not so numerous as fresh-water lakes, occur in large numbers in certain regions. The Caspian Sea with an area as large as Spain, the Sea of Aral, and a vast number among the mountains and table-lands north of the Himalaya; the Dead Sea in Syria; L. Utah, and neighbouring lakes among the mountains on the western side of North America; and among the mountains of South America and in the interior of Australia are examples of large salt water lakes. It will be noticed that all these lakes lie in an area of inland drainage, that they have rivers running into them, but that they have no outlet. On inspecting the above table it will be seen that the Black Sea is fresher than the Mediterranean, by reason of the greater supply of fresh water furnished by the rivers, and Edward Forbes showed that this freshening has caused certain of the shells of Mediterranean species to assume "monstrous" shapes. The Caspian is still fresher, and its fauna and fossils in recent deposits in the neighbourhood prove it to have once had connection with the Black Sea, from which it has been separated by changes in physical geography; it was then salter than at present, but is now growing salter

The

again every year, and the fauna now inhabiting its waters have likewise considerable affinities with North Sea types.Its surface level is 83.5 ft. below that of the Black Sea, while the surface of the Dead Sea is 1300 ft. below that of the Mediterranean. In all cases where rivers flow into depressions in the land, however these might have been formed (oscillating movements of the earth's crust might perhaps form such large ones as the Caspian basin), carrying with them certain salts in solution, if the lake have no outflowing river, the water must be carried away by evaporation, in which case the salts will be left behind, and the remaining waters become more and more saturated. It is stated that crystals of salt have been brought up from the Dead Sea, and on the shallow waters on its coasts evaporating in summer saline incrustations are left. same water which flows through the Sea of Galilee, a freshwater lake, renders the Dead Sea one of the most remarkable salt lakes in the world. And in this and all similar cases accumulation of salts will go on till the saturation point is reached, and then precipitation will commence. The region to the north of the Himalayas is comparatively rainless, owing to the mountains condensing the moisture carried by the south winds, and the rivers consequently do not carry into the lakes sufficient water to make them overflow their boundaries, hence they are salt. Lake For a similar Baikal, with an outlet to the sea, is quite fresh. reason the moisture from the south-west winds being condensed in great part by the Sierra Nevada, the lakes which lie in the great plains and table-lands to the east of that range have not a sufficient supply of water to cause them to overflow, and consequently they are salt, and are continually becoming salter. In 100 parts by weight of the water of the Great Salt Lake in that region, there are of chloride of sodium (common salt) 20:196; sulphate of soda 1834; chloride of magnesia 0.252; chloride of calcium a trace, making a total of 22:282. And by means of the old water levels in the form of terraces round its margin, it can be proved that it has shrunk very considerably, and therefore its salts must be becoming very much concentrated. On the surrounding plains a saline efflorescence is found, which the lecturer believed might be explained by the rain which saturated the rocks during the rainy season rising again to the surface charged with salts dissolved from the rocks, during the intense heats of summer. (To be continued).

SCIENTIFIC SERIALS

THE Zoologist for January and February contains reviews of the works of Capt. Shelley and the late C. J. Andersson. Dr. Gray contributes a paper on the Cetacea of the British Seas, and Mr. Harting has a supplement to his paper on the British Heronries, a subject on which there are several letters also published. Messrs. Stevenson and J. H. Gurney, jun., send Ornithological_notes from Norfolk, and Messrs. Gatcombe and Cordeux from Devon and Lincolnshire respectively.

THE Entomologist for January and February, among other articles of interest, contains one by Mr. H. C. Lord, on "The Lepidoptera of Switzerland," as far as could be obtained in a twelve days stay. Out of the sixty-three species of butterflies met with, twenty-four are not British. Many of the English commonest forms are among the most frequently found there. Colias Hyale is commoner in some parts than C. Edusa, and C. Mr. F. Walker continues Helice is not unfrequently found.

his papers on "Economy of Chalcidiæ."

SOCIETIES AND ACADEMIES

LONDON

Royal Society, Jan. 9.—“ On a new Method of viewing the Chromosphere," by J. N. Lockyer, F.R.S., and G. M. Seabroke. The observations made by slitless spectroscopes during the eclipse of December 11, 1871, led one of us early this year to the conclusion that the most convenient and labour-saving contriv ance for the daily observation of the chromosphere would be to photograph daily the image of a ring-slit, which should be coincident with an image of the chromosphere itself.

The same idea has since occurred to the other.

We therefore beg leave to send in a joint communication to the Royal Society on the subject, showing the manner in which this kind of observation can be carried out, remarking that, although the method still requires some instrumental details, which

B

[Feb. 20, 1873

chromospheric light is allowed to pass. The chromosphere is afterwards brought to a focus again at the position usually oc cupied by the slit of the spectroscope; and in the eye-piece is seen the chromosphere in circles corresponding to the "C" of other lines. The lens D is used to reduce the size of the sun's image, and keep it of the same size as the diaphragm at different times of the year; and the lenses F are used in order to reduce the size of the annulus of light to about inch, so that the pencils of light from either side of the annulus may not be too

FIG. I.

FIG. 2.

divergent to pass through the prisms at the same time, and that the image of the whole annulus may be seen at once. There are mechanical difficulties in producing a perfect annulus of the required size, so one inch in diameter is used, and can be reduced virtually to any size at pleasure.

The proposed photographic arrangements are as follows:" A large Steinheil spectroscope is used, its usual slit being replaced by the ring one.

December 6, 1872, at 11.30.

A solar beam is thrown along the axis of the collimator by a heliostat, and the sun's image is brought to focus on the ring-slit by a 3-inch object-glass, the solar image being made to fit the slit by a suitable lens.

By this method the image of the chromosphere received on the photographic plate can be obtained of a convenient size, as a telescope of any dimensions may be used for focussing the parallel beam which passes through the prisms on to the plate. December 7, 1872, at 11.30.

inch.

The accompanying solar profiles are copies of drawing made, on the dates stated, by means of the new method, which were exhibited by the authors at the meeting.

[Since reading the above paper it has come to our knowledge that Zöllner had conceived the same idea unknown to us, but had rejected it. Prof. Wenlock in America has tried a similar arrangement, but without success.-J.N. L., G.M.S., January 17, 1873.1

Feb. 13.-"On a new Relation between Heat and Electricity," by Frederick Guthrie.

It is found that the reaction between an electrified body and a neighbouring neutral one, whereby the eletricity in the neutral body is inductively decomposed and attraction produced, undergoes a modification when the neutral body is considerably

heated.

Under many circumstances it is found that the electrified

body is rapidly and completely discharged. The action of discharge is shown to depend mainly upon the following condi tions :-(1) The temperature of the discharging body and its distance from the electrified one. (2) The nature (+ or -) of the latter's electricity.

With regard to (1), it is shown that the discharging power of a hot body diminishes with its distance and increases with its temperature. But, concerning the temperature, it is proved that the discharging power of a hot body does not depend upon the quantity of heat radiated from it to the electrified body, but chiefly upon its quality. Thus a white hot platinum wire cannected with the earth may exercise an indefinitely greater dis charging power, at the same distance, than a large mass of iron at 100° C., though the latter may impart more heat to the elec trified body.

Neither the mere reception of heat, however intense, by the electrified body, unless the latter have such small capacity as to be itself intensely heated, discharges the electricity if the source of heat be distant: nor is discharge effected when the electrified body and a neighbouring cold one are surrounded by air through which intense heat is passing. But, for the discharge, it is necessary that heat of intensity pass to the electrified body from a neutral body, within inductive range.