a hollow sphere of lead by Francis Bacon. Again "Mariotte's Tube," as it is called (p. 120), is described and figured by Robert Boyle fourteen years before Mariotte mentions it. Morren's mercury pump for slow but accurate exhaustion is described and figured on p. 141 (Figs. 3, 4); by its means a vacuum of one-tenth of a millimetre of mercury may be obtained.

The Acoustics has been considerably augmented, for while in the 1868 edition it occupied fifty-two pages, it now fills fifty-five larger pages. We notice, among other things, an account and woodcut of König's stethoscope, and of his cylindrical resonator; of Helmholtz's apparatus for the synthesis of sounds; and various new woodcuts of manometric flames. We do not observe any mention of singing or sensitive flames. In the section devoted to heat, we do not find an account of Prof. Guthrie's experiments on the conduction of heat by liquids; or of the recent observations regarding the heat of the moon and certain stars; and the portion relating to the "Mechanical Equivalent of Heat" is still very meagre and insufficient.

The magnetism of iron ships might with advantage be alluded to in the account of Magnetism; and M. Noë's very powerful thermo-electric battery is also worthy of notice. On pp. 596 and 597 we are glad to observe capital figures and descriptions of the electrical machines of Bertsch and Carre; the latter appears to be a most desirable addition to the Physical Laboratory, as, even without a condenser, plates of 49 centimetres diameter give sparks 18 centimetres long, and the machine is not much affected by moisture. The apparatus figured on pp. 678-670 for demonstrating the attraction and repulsion of electric currents by currents, consists of new and improved forms of those devised by Ampère, and is extremely ingenious; as is also the form of solenoid described on p. 690. (Fig. 5.)

A few alterations in the text would be advisable if a table of errata is introduced; thus (p. 750) no explanation is given of the stoppage of a cube of copper when caused to rotate between the poles of a powerful electro-magnet, as soon as the magnet is made; neither is reference given to the explanation which in another form is given elsewhere. Again (p. 628) we read:"Kirchhoff

has concluded that the motion of electricity in a wire in which it meets with no resistance is," &c. A very few clerical errors are observable :-p. 185, M. Costa should be M. Corti; p. 246, topmost line, "substances by which their action," &c., should read "which by their action;" p. 289, line ten from the top, p should be p'; and p. 524, line 4, we find "plain polarised light."

These, however, are quite minor matters; the book was a good one at the outset of its career, and each succeeding edition has rendered it more and more complete. The above remarks are made rather as suggestions than in any spirit of adverse criticism. Ganot's Physics is a great addition to our scientific literature, and neither student nor savant could spare it from his library.

G. F. RODWELL

during the experiments. The appearance of this spectrum Its has in the meantime been carefully considered. extent and position suggest that the depth of the solar atmosphere far exceeds the limits hitherto assumed.

The accompanying illustration represents an apparatus constructed by the writer to facilitate the investigation. Evidently the expedient of shutting out the photosphere while examining the effect produced by the rays emanating from the chromosphere calls for means by which the sun

may be kept accurately in focus during the period required to complete the observations. The main features of the apparatus being shown by the illustration, a brief description will suffice. The parabolic reflector which concentrates the rays from the chromosphere (described in the previous article) is placed in the cavity of a conical dish of cast-iron, secured to the top of a table suspended | on two horizontal journals, and revolving on a vertical axle. The latter, slightly taper, turns in a cast-iron socket which is bushed with brass and supported by three legs stepped on a triangular base, resting on friction-rollers. The horizontal journals referred to turn in bearings attached to a rigid bar of wrought-iron situated under the table, firmly secured to the upper end of the vertical axle. The horizontal angular position of the table is adjusted by a screw operated by the small hand-wheel a, the inclination being regulated by another screw turned by the hand-wheel b. A graduated quadrant, e, is attached to the end of the table in order to afford means of ascertaining the sun's zenith distance at any moment. The index d, which marks the degree of inclination, is stationary, being secured to the rigid bar before described. The rays from the photosphere are shut out by a circular disc, f, composed of sheet metal turned to exact size, and supported by three diagonal rods of steel. These rods are secured to the circumference of the conical dish by screws and adjustable nuts in such a manner that the centre of the discƒ may readily be brought in a direct line with the axis of the reflector. The mechanism adopted for adjusting the position of the table by the hand-wheels a and b requires no explanation; but the device which enables the operator to ascertain when the axis of the reflector is pointed exactly towards the centre of the sun demands particular notice. A shallow cylindrical box, g, provided with a flat lid and open at the bottom, excepting a narrow flange extending round the circumference, is firmly held by two columns secured to the top of the table. A convex lens of 26 inches focus is inserted in the cylindrical box, the narrow flange mentioned affording necessary support. The lid is perforated by two openings at right angles, 005 inch wide, 2.5 inches long, forming a cross, the lens being so adjusted that its axis passes through the central point of intersection of the cross. The face of the table being turned at right angles to the sun, or nearly so, it will be evident that the rays passing through the perforations and through the lens will produce, at a certain distance, a brilliantly illuminated cross of small size and sharp outline. A piece of ivory, or white paper, on which parallel lines are drawn intersecting each other at right angles, is attached to the top of the table in such a position that the centre of intersection of the said lines coincides with the axis of the lens. This axis being parallel with the line passing through the centre of the disc fand the focus of the reflector, it will be perceived that the operator, in directing the table, has only to bring the illuminated cross within the intersecting parallel lines on the piece of ivory. Ample practice has shown that by this arrangement an attentive person can easily keep the disc f accurately in line with the focus of the reflector and the centre of the sun during any desirable length of time. The absence of any perceptible motion of the column of the focal thermometer during the experiments which have been made furnishes the best evidence that the sun's rays have been effectually shut out by the intervening disc, which, it should be remembered, is only large enough to screen the aperture of the reflector from the rays projected by the photosphere. It may be noticed that actinometric observations cannot be accurately made unless the instrument is attached to a table capable of being directed in the manner described; nor is it possible to measure the dynamic energy transmitted by solar radiation unless the calorimeter employed for the purpose faces the sun with the same precision as our parabolic reflector. It is worthy of notice that the lightness of the illustrated apparatus ren

ders exact adjustment easy, since screws of small diameter and fine pitch may be employed. It only remains to be stated that in order to admit of accurate examination of the spectrum before referred to, the thermometer is removed during investigations which do not relate to temperature, a cylindrical stem of metal, o 25 inch diameter, coated with lamp-black, being introduced in its place.

With reference to the result of recent experiments, it is proper to state that, at the present time, the sun's zenith distance being now nearly 60° at noon, no perceptible heating takes place in the focus of the parabolic reflector. The observations relating to temperature mentioned in the previous article, were made when the zenith distance was only one-third of what it is at present. The consequent increase of atmospheric depth, at this time, has completely changed the colour of the spectrum, and rendered the same so feeble that its extent cannot be determined. As seen last summer, before the earth had receded far from the aphelion, the termination of the spectrum reached so far down that an addition of o'15 inch to the radius of the disc fwould scarcely have shut it out. Now an addition of o'15 inch to the radius of the disc corresponds to an angular distance of 9′ 45′′; hence, assuming the radius of the photosphere to be 426,300 miles, the depth of the solar atmosphere cannot be less than 255.000 miles. And, judging from the appearance at the period referred to, there can be little doubt that a larger and more perfect reflector will enable us to trace the spectrum still further down. Consequently, a further enlargement of the disc fwill be required to extinguish wholly the reflected light from the solar atmosphere. It is reasonable, therefore, to suppose that the depth of the solar atmosphere will ultimately be found to exceed very considerably the foregoing computation.

It has been suggested regarding the instituted investigations of the radiant heat transmitted by the chromosphere, that the thermo-electric pile ought to be employed in combination with the parabolic reflector. The object of the investigation being simply that of proving by the feebleness of the radiant power transmitted to the surface of the earth that the chromosphere and outer strata of the sun's envelope do not possess radiant energy of sufficient intensity to influence solar temperature as supposed by Secchi, tests of the suggested extreme nicety are not called for.

With reference to the effect of increased depth, the small amount of retardation suffered by the rays in passing through the highly attenuated atmosphere of the sun, previously established, shows that the question of solar temperature will not be materially affected, even should it be found that the depth of the envelope is greater than the radius of the photosphere.

SIR

J. ERICSSON

THE RIGIDITY OF THE EARTH IR WILLIAM THOMSON'S views regarding the rigidity of the earth have been hitherto received in silence by those who entertain different opinions from him; but it does not follow on this account that they regard his position as unassailable. It is more satisfactory to attempt to establish positive results in science, than to criticise the labours of others; but as Sir William Thomson, by his letter in NATURE for January 18, manifestly invites discussion, I hope I shall be excused for making the following remarks.

When nearly ten years since I saw the abstract in the Proceedings of the Royal Society which he appends to his letter, I resolved to suspend my judgment until I had an opportunity for reading his papers in extenso. To such of your readers as happen to be interested in this question, and who have not yet seen these publications, I would venture to recommend a similar course, In the

"Philosophical Transactions" for 1862, the memoir on the rigidity of the earth is fully printed, and immediately following it is another designated "dynamical problems regarding elastic spheroidal shells and spheroids of incompressible liquid." The conclusions arrived at in the first are essentially and admittedly dependent on the investigations presented in the second. Not long after they were published I gave my best attention to the study of both, and it soon appeared to me that the problems treated in the second could have no physical bearing on the question of the earth's structure. The very title of this memoir partly reveals its character in this respect. In order to apply the results obtained in this memoir to the earth, it is supposed to be a spheroidal homogeneous elastic shell filled with incompressible fluid; whereas in such an inquiry the earth can scarcely be supposed to be otherwise than a heterogeneous solid envelope containing a fluid whose properties are not inconsistent with those of fluids coming under our notice. Under this form I have treated the hypothesis in the "Philosophical Transactions" for 1851, and also in subsequent publications.

66

Incompressibility is not a property of any known fluid; and Neumann, when referring in his comprehensive treatise on geology to the influence of pressure in promoting the density of the interior parts of the earth, expresses what is very generally admitted among philosophical geologists as well as physical inquirers, when he says that fluid bodies are endowed with far more compressibility than solids."* Hypotheses are often indispensable in physical inquiries where we are proceeding from the known to the unknown, but there are two conditions to which they should conform; first, they should be capable of verification by a comparison of the results to which they lead with those of observation, and secondly, they should not contradict established physical laws or the known properties of matter, unless the contradiction is specially explained and fully accounted for. The second of these conditions is clearly violated when the internal fluid of the earth is supposed to differ from all known fluids by being supposed to be incompressible. And this violation is especially flagrant when the solid matter enclosing the incompressible fluid is supposed to be at the same time elastic and therefore compressible, and when, moreover, the line of reasoning adopted as to the earth's internal structure pointedly depends upon these assumptions as to the properties of its fluid and solid portions. Sir William Thomson endeavours to prove, by a process of reductio ad absurdum that the interior of the earth is for the most part or altogether solid; in other words, he supposes the interior to be fluid, and then tries to show that the tidal actions produced in this fluid by the sun and moon must cause oscillations in the crust which have not been observed. He may justly claim to have proved that the earth does not consist of an elastic solid envelope enclosing a mass of the ideal substance called an incompressible liquid, but he has not proved the point which he intended to establish, namely, the absence of an interior fluid nucleus endowed with the properties commonly attributed to fluids. He also supposes throughout his investigations, in the same manner as was supposed by Mr. Hopkins, that the transition from the solidity of the shell to the fluidity of the nucleus is not gradual but abrupt. Those who maintain the validity of the hypothesis of the interior fluidity of the earth are far from holding this opinion. On the contrary, all observations hitherto made on the materials of the earth lead to the conclusion that the solid shell is so constituted as to present first a superficial coating whose mechanical properties we can partly ascertain by direct experiment; secondly, a mass whose density and rigidity probably increase with the depth from the outer surface; thirdly, an interior coating in which the effects of pressure are resisted by those of temperature, and where an imperfectly

* Lehrbuch der Geologie, i. p. 268, 2nd edition.

fluid and pasty mass is in contact at one side with the solid shell, and on the other with the more perfect fluid. This mass should be manifestly much more yielding and compressible than the perfectly solidified shell; for if compression tends to increase the rigidity of solid matter, the middle division of the shell, as just described, should be more rigid than its superficial portion, and very much more rigid than the interior pasty mass. The work performed by small changes of shape in the fluid nucleus due to the action of exterior disturbing bodies should thus be expended partly in producing small variations of density among the compressible strata of which it is composed, and partly in changing the shape of the yielding matter of the inner surface of the shell. The deformations of a shell consisting of homogeneous elastic matter, such as steel acted upon by exterior forces, must be the resultants of all the elementary deformations among its particles summed up or integrated. It would behave somewhat like a vibrating bell; but such is not the behaviour to be expected in a mass of discontinuous and heterogeneous materials. Vibratory motions in such bodies are for the most part extinguished by interferences, or their amplitudes are at least very much reduced.

If the conclusions deduced by M. Perrey of Dijon from his voluminous labours so often referred to by Mr. Mallet in his Reports on Earthquakes, be correct, some connection between these disturbances and the phases of the moon scems to be established which may be due to such comparatively feeble vibratory actions. Sir William Thomson's conclusions rightly interpreted show that the constitution of the fluid nucleus and the nature of the materials of the shell must be essentially different from what he supposes in order to establish these conclusions. A person who never saw a railway train might as justly reason as to the impossibility of travelling in it at high rates of speed, by demonstrating that the shocks experienced by perfectly rigid carriages connected without any compressible arrangements would be too great for travellers to endure, if not too great for the permanent integrity of the carriages themselves. In assuming the incompressibility of the fluid nucleus for the purposes of his indirect demonstration of the rigidity of the earth, Sir William Thomson makes a petitio principii nearly as vital as shocks incident to influence of buffers in reasoning on the the omission of the railway carriages.

I am at a loss to know where any warrant was found for affixing the property of incompressibility to the supposed fluid nucleus of the earth; and those who maintain the hypothesis of the interior fluidity of the earth are entitled to repudiate an assumption fastened on that hypothesis not only in opposition to evidence derived from experiments on fluids, but in direct contradiction to the arguments employed by them in discussing the question of the earth's structure. HENRY HENNESSY

IN

THE LANDSLIPS AT NORTHWICH N the "Notes" of the number of NATURE, for Jan. 25, I find one referring to the landslips at Northwich in Cheshire, by mistake called Nantwich. As the description given of these landslips and their cause is scarcely accurate, your readers may like to see a short account of them.

Northwich is the great centre of the Cheshire salt trade. The manufacture is principally carried on now at Northwich and Winsford, both towns lying in the valley of the River Weaver, though formerly Nantwich was engaged in this trade, and Middlewich still continues so to be. The position of the latter is indicated by its name, it lying between Northwich and Nantwich. The salt is found lying in two beds, called the upper and lower rock salt. The first bed is met with in the neighbourhood of Northwich at the depth of about forty yards, and

is twenty-five yards thick. Although brine springs had been known and worked as early as the time of the Norman Conquest or earlier, yet the bed of rock salt was only discovered in 1670 when searching for coal at Marbury, about a mile to the north of Northwich. During the last 200 years this rock salt has been worked, or to speak more correctly, for more than a century the upper bed was worked, when an agent of the Duke of Bridgewater sank lower still, and, after passing through about ten yards of hard clay and stone, with small veins of rock salt running through it, the lower bed of rock salt was discovered. This lower bed is between thirty and forty yards thick, but only about five yards of the purest of it is "got." This good portion lies at a depth of from 100 to 110 yards, according to the locality. In the neighbourhood of Winsford both beds are met with at a much greater depth. The whole of the rock salt obtained is got now from the lower bed, and last year it reached nearly 150,000 tons, probably the largest quantity ever obtained in one year. It may as well be said that this mining of rock salt has had nothing whatever to do with the subsidences spoken of, though the wording of the note would lead readers to expect the contrary. At present there is no danger to be expected from the lower bed of rock salt. The whole danger arises from the upper bed, as will be seen from the following account :-The salt trade of Cheshire is a very extensive one, and during the year 1871 upwards of 1,250,000 tons of white salt have been sent from the various works in that county. The whole of this immense quantity has been manufactured from a natural brine which is found in and around Northwich and Winsford, as well as in several other smaller places. This brine is produced by fresh water finding its way to the surface of the upper bed of rock salt, technically called the Rock Head. The fresh water dissolves the rock salt, and becomes saturated with salt. The ordinary proportion of pure salt in the brine is 25 per cent. To obtain the quantity of salt above mentioned, it would be necessary to pump 5,000,000 tons of brine. The pumping of brine is incessantly going on, and as a natural consequence the bed of rock salt is being gradually dissolved and pumped up. As the surface of the salt is eaten away, the land above it subsides. This subsidence is not spread over the whole surface, but seems to follow depressions in it, thus forming underground valleys with streams of brine running to the great centres of pumping. Wherever a stream of brine runs, there the subsidence occurs, and in many localities the sinking is very rapid and serious, but fortunately is almost always gradual and continuous. An immense lake, more than half a mile in length, and nearly as much in breadth, has been formed along the course of a small brook that ran into the river Weaver, and this lake is extending continually. Besides this gradual continuous sinking, which affects the town of Northwich very seriously, causing the removal and rebuilding of houses or the raising of them by screw-jacks in the American fashion, the raising of the streets and so on, there is a sudden sinking of large patches of ground, leaving large deep cavities such as described in your Note. These latter are more terrifying and dangerous. They are in the majority of cases caused by the falling-in of old disused mines in the upper bed of rock salt. These old mines were worked so as to leave but a thin crust of rock salt between the superincumbent layers of earth and the mines. The roof of the mine is supported by pillars of rock salt at intervals. Of course the weakest and most dangerous point is the old filled-up shaft. As most of these mines have been disused for nearly a century, the position of the old shafts is unknown. When the brine has eaten away the layer of rock salt left as a roof, the whole of the earth lying above falls into the mine, and an enormous crater-like hole, some 100 feet or more in depth, is formed, which in process of time becomes filled up with water, the mine itself being choked with earthy

matter. In the immediate neighbourhood of Northwich there are a great number of these rock pit holes, as they are called, and it is nothing very unusual for one to fall

in.

The rock miners, as they are called, were at work in the lower mine last year when one of these sudden subsidences occurred. They knew nothing of it. I have been myself under this hole, and it was a fearful one to look at when it first went in. There is no communication between the upper and lower beds, and the miners have about thirty yards of hard clayey stone and rock salt between them and the upper old mines. The subsidence more particularly alluded to in your Notes is not in the immediate neighbourhood of Northwich, but rather midway between Northwich and Winsford, near Marton Hall. It is rather difficult to know what is its cause, as there is no record of any mines ever being worked in that neighbourhood. The general belief is that the rock salt, which undoubtedly underlies the whole neighbourhood, has been gradually dissolved, and that a sinking has commenced as at Northwich; then that, owing to some peculiarity of the particular overlying strata-probably to their sandy nature, as quicksands are known to exist about Northwich-the earthy and sandy matter of the immediately overlying strata has been carried away by the brine streams till a large hollow has been formed. This has continued till the superincumbent mass could not be borne up any longer, and thus suddenly fell in, filling up the lower cavity, but opening a large crater-like pit from the surface.

A Government inspector has been to the neighbourhood, and his report is expected very shortly.

The whole neighbourhood of Northwich is well worthy of more attention than it has received, and it is surprising that our geologists have not been able to give a better account of the rock salt formation than has yet been done. THOS. WARD

NOTES

WE are glad to be able to state that the severe sentence passed upon M. E. Reclus has been changed, in consequence of the representations of the scientific men of this and other countries, into the comparatively mild one of exile from France.

WE understand that the Chair of Anatomy in the new German University of Strasburg has been offered to, and declined by, Prof. Gegenbaur, who has done so much to raise the scientific reputation of the University of Jena. A similar offer has also been made to Gegenbaur's distinguished colleague, Haeckel, the result of which is not yet announced.

THE Master and Senior Fellows of St. John's College, Cambridge, have elected Mr. J. B. Bradbury, M.D., of Downing College, Linacre Lecturer in Medicine in the room of Dr. Paget, who has been elected Regius Professor of Physic.

THE Royal Commission on Scientific Instruction and the Advancement of Science recommenced their sittings yesterday.

THE two Smith's Prizes of the University of Cambridge have been this year awarded to the First and Second Wranglers respectively.

WE regret to learn that the Australian Eclipse Expedition has proved a failure, through the unfavourable state of the weather at the point of observation.

IT is with great regret we have to record the death on Wednesday, January 31, at Torquay, of Dr. G. E. Day, F.R.S., late Chandos Professor of Medicine in the University of St. Andrew, at the age of 56. Our columns have borne frequent evidence of the extent of Dr. Day's acquirements in many branches of

THE name of Colonel Chesney, F.R.S., of the Royal Artillery, who died on Tuesday, the 30th ult., at his residence near Kilkeel, Co. Down, Ireland, in the 83rd year of his age, was almost more familiar to the last generation than to this. Among his various titles to eminence as traveller, savan, and military critic, he will be chiefly known as "the pioneer of the overland route to India." It is now nearly forty years since General, then Captain, Chesney returned from his explorations of the Euphrates for the purpose of establishing steam communication with India vid Egyot and Asia Minor, to ask the Government to give him the command of an expedition. The demand was granted; two vessels, the Tigris and the Euphrates, were placed at his disposal. The indefatigable manner in which he prosecuted his scheme, in the face of many disappointments and discouragements, is well known. He has himself written the history of his travels and adventures; and the lines of communication now in existence bear witness to the practical value of his projects. General Chesney has for many years back enjoyed the repose which was the fitting reward of much arduous toil; and now leaves behind him the record of a useful, honourable, and well-spent life.

DR. WILLIAM BAIRD, F. R.S., whose death we recorded last week, after a long and painful illness, was born at Eccles, in Berwickshire, in the year 1803, educated at Edinburgh, and received in 1823 an appointment as surgeon from the East India Company. While in this office he visited India, China, and many other countries, the natural history of which he carefully studied. In 1831 he published a paper "On the Luminosity of the Sea," in Loudon's Magazine of Natural History, and from that time became a frequent contributor to the scientific journals, more especially to the "Transactions" of the Berwickshire Naturalists' Club. In 1838 he compiled a Cyclopædia of the Natural Sciences. In September 1841 he was appointed an Assistant in the Zoological Department of the British Museum, which office he filled till his death. In 1851 his mono graph on the British Entomostrac us Crustacea, a work of great ability and research, was published by the Ray Society. Between the years 1838 and 1863 he contributed a number of papers on the Entomostraca to the "Annals of Natural History," and the "Proceedings" of the Zoological Society. During the latter years of his life his attention was principally given to the Entozoa, of the then known species of which he had as early as 1843 drawn up a catalogue, which was published by the trustees of the British Museum. Numerous papers on the same subject were also contributed by him to the "Proceedings" of the Zoological Society, the "Transactions" of the Linnean Society, &c. Latterly he was engaged in preparing a general catalogue of the Entozoa, for which he had accumulated a vast amount of material. His knowledge of some other branches of natural history was equally extensive and profound, and his death will leave a gap among those who were acquainted with his varied acquiremen's, and the courtesy and readiness to assist displayed to all who sought his help or advice.

THE Academy records the death of Prof. Trendelenburg, of Berlin, who had attained a two-fold eminence as a philologist and Aristotelian commentator, and as an original thinker.

Royal Society and of the College of Physicians. Prof. Brodie was elected in 1865, and was the first professor under the new ordinance, having previously resigned the Aldrichian Professorship of Chemistry, which he had held since the resignation of the late Dr. Daubeny, and which chair was suppressed in 1866, the revenues being applied to the payment of a salary of a Demonstrator, and to the purchase of chemical apparatus or other means towards the study of chemistry in the University.

IN the Gazette of India is the following tribute to the memory of the late Archdeacon Pratt:-"The Governor-General in Council has received with deep regret official intimation of the death of the Venerable the Archdeacon of Calcutta, the Reverend J. H. Pratt, on the 28th ultimo, at Ghazeepore, in the NorthWestern Provinces. The Governor-General in Council cannot allow the death of Archdeacon Pratt to pass unnoticed by the Government which he served so long and so well. Mr. Pratt entered the service in the year 1838, and was appointed Archdeacon of Calcutta by the late Bishop Wilson on the 6th October, 1849. Under the ordinary rules of the service, Mr. Pratt would have retired in October, 1867, but so efficiently had he filled his high office in the Church, that he was solicited by Government, with the full approval of Her Majesty's Secretary of State, to continue to hold it. In adopting this course the Government was moved not only by its own appreciation of the Archdeacon's services, but the strong recommendation of the late Bishop Cotton, who bore testimony to Archdeacon Pratt's eminent scientific attainments and university distinctions, to the active part which he had taken in the management of the diocese, and in the promotion of all good works, and to his personal piety and high Christian character. At a later date Her Majesty's Secretary of State, in sanctioning the retention of Archdeacon Pratt in the service until October 1872, remarked:-'I cannot refrain from expressing the high sense I entertain, in common with the present Bishop of Calcutra, the Lieutenant-Governor of Bengal, and your Excellency in Council, of the zeal and ability with which he has for so many years faithfully and laboriously discharged the duties of his Office.' The Governor-General in Council feels assured that the death of the Venerable Archdeacon will be mourned by the entire Christian community in India."

IT is announced that Professor Flower will commence his annual Hunterian Lectures on Comparative Anatomy in the Theatre of the Royal College of Surgeons on Friday, the 16th inst., at four o'clock. The lectures will be continued at the same hour every Monday, Wednesday, and Friday until the 27th of March. The subjects to be embraced by the present course are the modifications of the organs of digestion, including the mouth, tongue, salivary glands, alimentary canal, liver, and pancreas. These will be treated of in detail in the various animals composing the class Mammalia, and if time should permit, a review of the principal variations of the same parts in the other Vertebrata will follow. The lectures will be illustrated as fully as possible by specimens from the Museum, and by diagrams, and it should be added, are open without fee to any gentleman presenting his card at the door.

The