cal and mineralogical features which characterise volcanic phenomena. For although mechanical force is admitted to be convertible into its equivalent in heat, which heat may in its turn set in operation chemical action, still no such forces, either alone or combined, can trans.nute one chemical element into another, or bring about the formation of products having at all times a definite chemical and mineralogical constitution, out of the incongruous materials likely to be met with on the sides of such faults, or cracks, or contraction. Our present knowledge of the mineral characters of the earth's crust does not entitle us to entertain the supposition that the substance of the rocks immediately contiguous to fissures of this character occurring in so many different parts of the globe, could in all, or even in other than solitary instances, when fused by the action of mere heat, afford products identical with those of known volcanoes. On the other hand, nothing is more certain, from the examination of volcanic products, than that, no matter from what part of the world they be derived, whether from volcanoes situated near the north or south poles, in the islands of the Pacific or Atlantic oceans, or from the craters of the Andes or the Apennines, they are all identical in chemical or mineralogical constitution-a result which indicates forcibly that that they must be derived from some one common source, and not be mere local accidents, as Mr. Mallet's hypothesis would require us to assume. For these and other reasons which we need not bring forward on the present occasion, it does not seem probable that this hypothesis will receive the adherence of either chemist, mineralogist, or geologist.

In conclusion, attention might here be directed to the disadvantages which, in a pecuniary point of view, the British student labours under when making himself acquainted with foreign science by means of translations. The original pamphlet of Prof. Palmieri in Italian, and its translation into German by the eminent chemist, Rammelsberg, were procured here in London for the small sum of eighteenpence each, whereas English translations of scientific works, got up, however, in superior paper, wide margin, and elaborate covers, can rarely (if ever) be obtained under several times the cost of the original works. DAVID FORBES

OUR BOOK SHELF

Human Physiology the Basis of Sanitary and Social Science. By T. L. Nichols, M.D. Pp. 479; woodcuts. (Trübner, 1872.)

THE title "Human Physiology," which alone appears on the back of this book, is misleading, and even the title as given above would scarcely prepare a reader for what he will find. The preface, however, gives fair warning. "Physiology," writes Dr. Nichols, "the science of life, has been handed over to the medical profession, which has an unfortunate interest in the popular ignorance of sanitary laws; while metaphysicians, moralists, and theologians have confused rather than enlightened our ideas "as to the moral nature of man and his consequent social requirements." This seems rather hard on the doctors, who have certainly done all that has yet been done in preaching the laws of health and in getting them carried out, both by public supervision or compulsion and by private influence; but the whole volume is an exemplification of the latter part of the melancholy result, whether due to those designing persons who study metaphysics,

morals, and theology or to some other cause. Dr. Nichols is an ardent advocate of the numerous theories which blind and bigoted Science has consistently and universally refused to accept, to the great disgust of circle-squarers, anti-Newtonians, popular "scientists," and Social Sciencemongers. The first section of the book treats of preventible mortality, poverty, ignorance, drunkenness, and prostitution; the second of matter, force, and life, including adverse criticism, on the feeblest grounds, of the doctrines of evolution and of materialism, with some remarkable proofs of immortality." The third part gives a popular account of the human body, with some of the oddest illus trations ever printed. The fourth treats of the laws of generation, including chapters on love and marriage, hereditary transmission, and problems of the sexual relation. This section is, perhaps, the best in the book, and the conclusions are sensible enough. The fifth, part on its subjects are handled with freedom and modesty, while health, disease, and cure, contains a good many useful and obvious remarks on the value of cleanliness, exercise, and temperance, together with a number of utterly unsupported or demonstrably false propositions. The last part, is devoted to the discussion of morals and society, in which important questions in political economy, ethics, agriculture, are stated, benevolent wishes for all classes of mankind are expressed, and the questions left much as they were found.

In a book of this kind the reader is not surprised to entarianism, clairvoyance, homœopathy, animal magnetism, counter the old and new dogmas of phrenology, vegeanti-vaccination, and cure by Psychic force. But though unscientific and sometimes anti-scientific, the author would deserve credit for putting before the public information which, however trite, is too little acted on, if his assertions of the wonderful cures he has made by hydropathy at Malvern, and the quotation from "a little book," by Mrs. Nichols on the same subject, did not suggest a doubt whether in his case singleness of motive can be admitted in excuse of ignorance. P. S.

LETTERS TO THE EDITOR

[The Editor does not hold himself responsible for opinims expressed by his correspondents. No notice is taken of anonymous communications.]

Dr. Bastian's Experiments

MR. LANKESTER asks me several questions relating to the experiments by Dr. Bastian, reported by me in NATURE a few weeks ago. In reply I beg to say that new Cheddar cheese was used. The cheese was not weighed, but the quantity added to the contents of each flask probably did not exceed two grains. The turnip infusion was filtered before it was introduced into the flasks: the filtrate was limpid. After boiling, the liquid was somewhat turbid, and contained visible particles. Feb. 3 J. BURDON SANDERSON

Eyes and No Eyes

MR. RAY LANKESTER'S letter has reminded me of a little experiment of my own which converted me to Bastianism. I had some turnip and cheese flasks which Dr. Bastian had been kind enough to prepare in my presence. I took them home and in due time examined the contents in a good microscope, using what I thought adequate power. I saw nothing, and went triumphant to Dr. Bastian to report my failure, taking the flasks with me. Dr. Bastian looked at the fluid, smelt it, and told me he would eat his hat if it was not full of life. I thought he would have to eat his hat. He put a drop under his microscope and told me to look. It was full of small Bacteria. I was a good deal puzzled at first, but after a little discussion I found out why I had failed to see what was in the fluid. Without going into details, I may say that the short result was that I had been rather a muff with the microscope. May not this explain some other failures ?— not Mr. Lankester's, of course.

QUERY]

Meteor at St. Thomas

THE enclosed reached me from a meteorological correspondent in St. Thomas. The records of such phenomena must be rare; there may be something peculiar in this one; I therefore forward it to you. RAWSON RAWSON Government House, Barbados, Dec. 30, 1872 "On November 30, 1872, at 8h 10m P. M. a beautiful large meteor was observed, which passed from west to east with great brilliancy, and exploded in the zenith in numerous little stars. It lasted about three seconds. A little after a rumbling noise, like distant thunder, was heard. It is reported by the watchman of the floating dock, which lies at present on the eastern beach of Long Bay in eight feet water, for repairs, that he was sleeping on the platform under an awning; he awoke from the heat and the strong light which passed close to him through the lattice work; and some ashes fell on the dock which he found but did not collect, not knowing that it was of value. As is well known, aerolites travel at the rate of 10,000 feet per second."

Brilliant Meteor

LAST night about 10.0, the moment after leaving the room in which I had been lecturing, at Wordsley, near Stourbridge, the ground about me was lighted up as by the sudden flash of a near lantern or the emergence of the full moon from a bank of cloud. On looking up at the sky, I saw a rocket-like object shooting down with a slightly zigzag motion like that of a fish, and leav ing behind it a trail of mingled and mingling tints of green, purple, and yellow of nearly the semi-diameter of the moon. After a first thought about fireworks, I felt sure it was a meteor, and looked about for the constellations, so that I might be able to describe its path. The sky, however, was covered with clouds, only a star here and there being visible, and the moon, though easily seen, presenting a very hazy appearance. From inquiry at the Rectory as to the aspect of the schoolroom from which I had just come out, I judge that the course of the meteor must have been from north-west to west. When I first saw it, it was about 40° or 50° above the horizon, and it traversed about half the remaining space before disappearing, occupying, I estimate, about six seconds in doing so. Its path formed an angle of about 40° with the horizon.

From the fact that the sky was covered with clouds and that the meteor illuminated the ground with a light superior to that of the "half" moon shining at the time, I judge that the meteor was between the clouds and the earth. This nearness, would, of course, be an element in its great apparent size (which would be added to by the zigzag motion); and as it would also prevent its being seen at great distances and by many observers, I have, after some hesitation, penned this record of my very imperfect observations. GEORGE ST. CLAIR

London, Feb. 4

The Antinomies of Kant

My attention has been directed by a friend to an address by Prof. W. K. Clifford, in Macmillan's Magazine for this month, containing a curious misrepresentation of Kant's teaching, and therein an instructive instance of ultracrepidism. The professor remarks: "The opinion that at the basis of the natural order there is something which we can know to be unreasonable to elude the process of human thought. . . is set forth first by Kant, so far as I know, in the form of his famous doctrine of the antinomies or contradictions, a later form of which I will endeavour to explain to you." "This doctrine," he continues, "has been developed and extended to the great successors of Kant, and this unreasonable, or unknowab'e, which is also called the absolute and the unconditioned, has been set forth in various ways as that which we know to be the true basis of all things."

I am sure I should not be allowed, in the columns of NATURE, sufficient space to point out in detail the misapprehensions involved in these remarks. It is plain to me that Professor Clifford has approached the very difficult subject of Kant's Antinomies from the system of Sir William Hamilton. To start with Hamilton, however, is to be handicapped in the pursuit, and to augment the difficulties to be surmounted. In truth the doctrine Professor Clifford expounds is simply that of Hamilton; but Hamilton did not either develop or extend the Antinomies of Kant. He never understood them, but carved his little system out of a few splinters he gathered by the way. All Hamilton's characterisations of Kant are ludicrously false. This doctrine

of the Antinomies does not answer, either, to Professor Clifford's touch. The Antithetic is not "unreasonable," nor does it "elude

the processes of human thought;" for, though it presents an un

avoidable illusion, Kant has used reason, with matchless power and subtlety, to show that reason is master of the position, can solve every Antinomy, and can therefore guard against the very possibility of delusion. It is not any "natural order" of thought or things, that is found to be unreasonable, but the offence against common logic which is involved in every attempt to prove the thesis or antithesis of an antinomy. I refer all who care to see the thing for themselves to Kant's K. r. V., Element. ii. Th., ii. Abth., ii. Buch., 2 Hauptst., 7 Abschnitt: Kritische Entscheidung des kosmologischen Streits der Vernunft mit sich selbst et seq. C. M. INGLERY

Athenæum Club, Jan. 21

The Source of the Solar Heat

IT gave me great pleasure to find that Captain Ericsson has taken the same views as myself with regard to the Source of the Solar Energy; but there is a certain part of his article in NATURE, vol. vi. p. 539, which I do not quite understand.

My views on this subject were sent to the Royal Astronomical Society, and were published in the Monthly Notices for April 1872, where it was easily shown that if E be the total energy destroyed in a given time by the crushing-in of the sun's massE = 80 pr3

the contraction of that radius in the given time; all corresponding to the present epoch.

To find zo we must express E in thermal units by means of the dynamical theory of heat, and equate the result to the total amount of heat radiated by the sun; and it is easy to show that z, must be 129 ft. per annum; and since Captain Ericsson finds the eontraction to be 121 ft., we are so far in agreement. But pr3 is the mass of the sun, and g varies inversely as r2, hence we may write

E=CZ R2

where C is a constant, and R, Z, the values of the radius and of the contraction at any other epoch of time. Now there is no connection between Z and R; if Z varies as R2, then E is constant; if Z varies as R, which I believe to be the most probable assumption, then E varies inversely as R, and the total solar radiation must be slowly increasing; but I see no reason whatever for supposing that Z varies directly as R4, so that the solar radiation must be diminishing in proportion to the square of the sun's radius. MAXWELL HALL Jamaica

The Twinkling of the Stars

THE phenomenon observed and described by G. F. Burder in NATURE of Jan. 23, p. 222, does not, as I understand it, account in any way for the twinkling of stars, seeing that, by means of any two lights (gas lamps for instance) at the distance of a few hundreds of yards, the same effect may be observed, and this quite irrespective of the angle at which they are placed with reference to the horizon or the "blind spot" of the observer's eye. THOS. HAWKSLEY

Meteorological Cycles

THE following observation may possess some interest in connection with the subject of recurring meteorological cycles. It is found at the conclusion of Mr. Consul Wallis's report on the trade and commerce of Costa Rica for 1867, dated June 1, 1868 (Parliamentary Papers for 1868-69, vol. lix. p. 520) :-"In the state of the public health there is a marked and satisfactory improvement to report. No reason can be assigned here for the large number of epidemic disorders which have afflicted this country for the last ten years and since the visitation of the cholera, nor for the improvement which took place in the eleventh year." R. G.

London, Jan. 2

ON THE OLD AND NEW LABORATORIES AT THE ROYAL INSTITUTION*

OF

II.

F the next great name connected with our Institution, namely, Michael Faraday, of his life and his discoveries the history has been already written, so far indeed as it can be written, by Bence Jones, by Tyndall, and by Gladstone. Si monumentum quæris circumspice. These volumes of notes, from 1831 to 1856, will give some idea of the amount of work which he did in our laboratory; and their value will be better appreciated through the consideration that before these notes were made, no less than sixty of his scientific papers had been printed, nine of them in the "Philosophical Transactions"

Those of us who were present at Tyndall's two memorable lectures on "Faraday as a discoverer" are not likely to forget the impression of the man left by them on our minds; and for those who were not present it would be an office thankless to your lecturer and burdensome to his hearers, to contribute a feeble reproduction of those life-like memoirs, For our present purpose it will be sufficient to say that the entire fabric of those brilliant and manifold contributions to human knowledge was wrought out within the walls of the Royal Institution.

His great experiments have been so often and so well exhibited in this theatre, that some apology is needed for bringing any of them before you again; but in repeating for my own instruction some of those which bear more particularly upon the subject of Light, I have been tempted to reproduce one of them here. In doing this I I have been perhaps moved more by a fascination of the phenomenon, and by a piece of instrumental good fortune which enables me to introduce an old friend under a new

garb, than by any better reason. The experiment in question is that which Faraday called "the magnetisation of light, and the illumination of the lines of magnetic force;" we should now term it the rotation of the plane of polarisation under the influence of the magnetic field. And in order that we may not even by inadvertence confuse the rotation here produced with that due to quartz, or oil of turpentine, I will draw your attention, by way of memorandum, to the nature of the magnetism produced by spiral currents in given directions, and of the rotations of free currents produced by magnets.

[The lecturer then showed the opposite rotations of two sparks discharged about the two poles respectively of an electro-magnet, and the reversal of those rotations, first by a change of the poles, and secondly by a reversal of the direction of the sparks.]

You now see upon the screen an image of the figures produced by a magnificent piece of heavy glass under the action of polarised light. Its size enables me to make use of about four times the amount of light usually available in this experiment; and I have taken advantage of the figure which its imperfect annealing produces, to vary the effect upon the screen. The dark parts of the figure indicate the parts of the beam in which the vibrations are perpendicular to those transmitted by either polariser or analyser, and which are consequently cut off. Now if anything should intervene to change the plane of those vibrations a portion of them will be transmitted, and a partial illumination of the screen will ensue. This turning of the plane of vibration is effected by the magnet as soon as its force is developed by the electric current sent through its coils.

[The lecturer then dispersed" the dark lines of the figure by means of a plate of quartz; and after turning polariser and analyser so as to colour the centre of the field with the tint intermediate between red and violet (teinte sensible), he showed that when the magnet was excited the field was rendered red or green according to the direction of the poles.]

* Continued from p. 224.

Professor Frankland before coming to us had isolated the compound radicals Methyl, Ethyl, and Amyl, and had proved their resemblance to Hydrogen. He had also combined them with the metals zinc, tin, mercury, and boron. By this means he had obtained a very powerful chemical reagent, which proved of eminent service in subsequent operations. An instance of its power will be found in zinc- ethyl, which by its rapid combination with oxygen of the air, bursts into spontaneous combustion as soon as a flask containing it is opened.

In conjunction with Mr. Duppa, Prof. Frankland worked in our laboratory at the artificial formation of ethers. They treated acetic ether with iodine and with the iodides of methyl, ethyl, and amyl; and by their means they arrived at a method for the formation of many organic substances which had previously been obtained only through the agency of animals or of vegetables.

In 1866 Dr. Frankland determined by a long series of calorimetric experiments the maximum amount of force capable of being developed by given weights of the diffcrent foods commonly used by men.

In the following year he investigated the effect of pressure (up to 20 atmospheres) upon the luminosity of flames of hydrogen and of carbonic oxides. He found that these flames, so feebly luminous at ordinary atmospheric pressure, burn with brilliant light under pressures of from 10 to 20 atmospheres, and that the spectra of these brilliant flames are perfectly continuous. From the latter circumstance he infers that solar light may be derived from glowing gas and not from incandescent solid or liquid matter.

As these researches have so important a bearing upon spectral analysis and solar physics, I will venture to repeat one or two of the experiments. Here are three closed tubes filled respectively with hydrogen, oxygen, and chlorine, at atmospheric pressure. The densities of these substances are in the proportions 1: 16: 35; and if the spark from an induction coil be made to pass through them, the luminosity of the discharge will be found to be nearly in the same proportions. That this result is really due to the density, and not to the chemical constitution of the gases, may be proved by allowing the discharge to pass through this tube, and by pumping air into it during the discharge. It will then be seen that the brilliancy increases with the pressure.

These researches were suggested by an old experiment of Cavendish's, in which he exploded a mixture of oxygen and hydrogen, first under atmospheric pressure and then under a pressure of from 10 to 12 atmospheres. In the first case there is much noise and little light; in the second, a brilliant flash and no noise. The labours of Dr. Frankland have rendered this experiment intelligible, and have correlated it with other phenomena.

Of Dr. Frankland's successor, Dr. Odling, I should have had more to say, had he not been attracted by a well-deserved offer of the chemical chair at Oxford. As a member of that University I rejoice at the appointment, while here we regret the loss.

Of Faraday's successor, John Tyndall, I am greatly at a loss how to speak. In this place his presence seems so near to us, his thoughts so subtle, his words-even when rung back to us from those busy cities far away on the other side of the Atlantic-so familiar and yet so stirring, that it behoves us that ours should be wary and few. Few men have brought so large a burden and bulk of contribution to the common stock of knowledge; but still fewer have inspired in his hearers so strong a love, such ardent enthusiasm for the subjects of his research.

It is now twenty years since Prof. Tyndall began his researches in our laboratory. During the first thirteen years he produced no less than thirteen papers, which were printed in the "Philosophical Transactions :" on Sound, on Diamagnetism, on "Glaciers and Ice, on the

Radiation and Absorption of Heat, and on Calorescence. In these he established the important fact that if the various gases be arranged in order according to their power, first of radiating heat, and secondly of absorbing radiant heat, the order will be the same in both cases. He further proved that the chief absorbing action of our atmosphere on non-luminous heat is due to its aqueous vapour. He applied his discovery to the explanation of many meteorological facts: e.g. the great daily range of the thermometer in dry climates; the production of frost at night in the Sahara; the cold in the table-lands of Asia, &c.

He discovered also the means of separating the invisible from the visible radiations, and proved that in the case of the electric light the former is no less than eight times as powerful as the latter. He also made the daring experiment of placing his eye at a focus of dark rays capable of heating platinum to redness.

Since 1866 his attention has been largely occupied in examining the action of heat of high refrangibility (instead of low), as an explorer of the molecular condition of

matter

In this investigation one obstacle to be overcome was the presence of the floating matter in the air. The processes of removal of these particles became the occasion of an independent research, branching out into various channels; on the one hand, it dealt with the very practical problem of the preservation of life among firemen exposed to heated smoke; and, on the other, it approached the recondite question of spontaneous generation.

He subjected the compound vapours of various substances to the action of a concentra ed beam of light. The vapours were decomposed, and non-volatile products were formed. The decompositions always began with a blue cloud, which discharged perfectly polarised light at right angles to the beam. This suggested to him the origin of the blue colour of the sky; and as it showed the extraordinary amount of light that may be scattered by cloudy matter of extreme tenuity, he considered that it might be regarded as a suggestion towards explaining the nature of a comet's tail.

[The lecturer then exhibited the polarisation of light scattered by small particles suspended in the medium traversed by a beam from the electric lamp, employing for the purpose the chromatic effects due to the circular porlarisation of quartz.]

His volume of contributions to molecular physics in the domain of radiant heat, which contains only his original investigations on this subject, would alone suffice to show what is doing in the laboratory of our Institution.

If we compare him to Faraday at the same time of life, he has still many years of intellectual energy, the conversion of which into its scientific equivalent may, perhaps, be effected within these walls.

No one has regretted the destruction of the laboratory of Davy and of Faraday more than Prof. Tyndall. He almost prayed for the preservation of the place where their discoveries had been made; but as soon as he saw that in our struggle for existence such material aids as improved buildings would conduce alike to the progress of science and to the permanence of the Institution, he withdrew his objections, and threw all his powers into making the new laboratories as perfect as possible for the good of his successors.

I add a few words on the reasons which led the managers to recommend the rebuilding of our laboratories, and the consequent demolition of the place where the great discoveries that I have touched upon were made. In the opinion of those best qualified to judge, our chemical laboratory was badly ventilated, badly lighted, badly drained, and quite unfit to be occupied for many hours daily. It was probably the very worst, and certainly all but the worst chemical laboratory in London; and compared with more modern ones both at home and abroad,

it was nowhere. The physical laboratory had remained for nearly seventy years in its original state. At first it was said to be equal to any laboratory; but then there were hardly any in existence in this country; and during the last few years such splendid edifices have arisen in London, in Oxford, in Cambridge, in Manchester and in Glasgow, and elsewhere, that the laboratory of Davy, of Faraday, and of Tyndall was much inferior to the private laboratories of the professors who carry on their course of instruction in public rooms of still greater size and extent of resource. The main purpose of our laboratories is research, and instead of offering by their excellence an inducement to professors to come and to stay, the one was a makeshift, the other a noble relic. Neither afforded facilities which were not offered in a larger measure elsewhere. And those only who know what is going on both at home and abroad can form an adequate idea of the competition which, in this respect alone, will prevail for a generation to come.

By the construction of new laboratories this material disadvantage will be removed. Future professors will have buildings constructed to aid research. Your liberality has spared no judicious expense; and, so far as the site would admit, our laboratories will be as perfect as the skill of our architect and the advice of our professors can make them.

In conclusion, let me lay before you what must still be done, in order that there may be earned for the new laboratories a reputation comparable with that which has hitherto proved both our glory and our support.

Our first and foremost object, beyond bricks and mortar, and money, and apparatus, must be to find a succession of professors of the old type; men who love research. But even Faraday would perhaps have been compelled to leave us, on account of the smallness of the sum which we could afford him, had not the endowment of the chemical chair, with 100l. a year, by the late Mr. Fuller, happily intervened. This timely endowment was probably a critical turning point in the history of the Institution. We may not easily find successors worthy of the great names who have gone before them; but we may do much toward preventing mistakes in future appointments by keeping steadily in view, that the promotion of natural knowledge is our main object; and that instruction and amusement, and brilliant audiences are all secondary to our principal purpose. Not that these subsidiary purposes are to be neglected or despised; and I, as your Treasurer, should be the last to undervalue them, but we feel confident that if the main purpose is effected, all the others will follow as a simple sequence.

Secondly, when we have found professors of the type that I have described, our next need is that we may be able, from independent resources at the disposal of the Institution, to offer them a remuneration which, all things taken into account, shall be an equivalent to what they would receive elsewhere. So that neither Government appointments, nor University professorships, nor the liberality of mercantile men, should be able to lure them from the path of discovery, to tuition, to arts, or to manufactures.

The one act of wisdom, among the many aberrations of an eccentric member of Parliament, saved Faraday to us, and thereby, as seems probable, our Institution to the country. The liberality of a Hebrew toy-dealer in the East of London has made the rebuilding of our laboratories possible.

It is said that Mr. Fuller, the feebleness of whose constitution denied him at all other times and places the rest necessary for health, could always find repose and even quiet slumber amid the murmuring lectures of the Royal Institution; and that, in gratitude for the peaceful hours thus snatched from an otherwise restless life, he bequeathed to us his magnificent legacy of 10,000l. If this evening's discourse shall have ensured one such blissful