solution, i.e. pv const., and PV = const., the above result follows at once. Substantially the same proof was given by Nernst in his "Theoretische Chemie."

Quite recently, however, a new and novel proof of the same theorem was published by Lord Rayleigh in the columns of NATURE. In this proof Lord Rayleigh avoids the assumption of the equation PV const., and herein lies a definite advance in the subject. The proof is based on the validity of Boyle's law for the gas, and Henry's law; but as the solvent is assumed to be involatile, it was objected by Lord Kelvin that the great majority of cases would thereby be excluded. So far as I can see, a small addition to Lord Rayleigh's proof will suffice to free it from this objection.

Besides this, I think that Lord Rayleigh's proof may be generalised so that even the assumption of Boyle's law for the gas is not required, at all events formally.

The primary assumption to be made is that for isothermal equilibrium the ratio of the concentrations of the substance in question, as gas and as solute, remains constant. This is usually known as the Distribution-Law, and cannot be regarded as a mere deduction from Boyle's law, and a certain form of statement of Henry's law. Recent research rather goes to show that it is a fundamental law of great generality. Accordingly I venture to employ Lord Rayleigh's method of proof, as follows.

ad and ef are two pistons, ef being impermeable, and ad permeable for the solvent alone. be and b'e are two fixed walls, of which b'c' is impermeable and be permeable for the solute

only. The piston ad is for the present fixed, and encloses a volume V of solvent between itself and bc. Suppose the cylinder to have unit section, and denote height of upper piston above the fixed semi-permeable wall by x. The whole process is conducted at the constant temperature 1. Suppose now that between ef and b'c' there is enclosed a quantity of the solute as gas, of volume z, temperature and pressure p, the amount being so chosen that it is just sufficient to saturate the volume V of solvent at this temperature and pressure. Let p denote density of the gas and suppose p = p2 p' (p) to be the isothermal equation of state for the gas, where p is an undetermined function. Take as unit of mass the mass of the enclosed gas. Allow the upper piston to rise reversibly to a height x, which is a very great multiple of the initial height. The work done in this process is:

noting by c the concentration of the solution at any moment, we have during the downward stroke :

px + cV = I

= K (Distribution-Law).

Now the term in brackets is zero if p() has the form log ≈ or any positive power of 2, so that it vanishes if (:) has the form a log + bo+b1z+b222+ &c. Hence it vanishes if '() has the form + b2+b2%+b222+ &c., since the latter series is by hypothesis convergent.

a

That is to say, pʊ = PV if the isothermal equation of

state is

or

This includes the equations of Boyle and Van der Waals as special cases.

The equation pv=PV is thus a formal consequence of the distribution-law and the expressibility of p as an infinite power series of p. However, when Boyle's law does not hold, this result loses much of its significance, as it does not then lead to an equation of state for the solution. So that this slight extension of Lord Rayleigh's result is not perhaps of much practical use. Holywood, Co. Down. F. G. DONNAN.

Of course, from (10 - N) the nearest multiple of N must be subtracted.

Examples: (1) N = 7. Take a = 1; then 10a N Z is a multiple of 7 when a + 3a1 +2а¿ − az − zas is divisible by 7.

can be divided by 103 without residue.

3, and

27 (α6 + 10a7)

in the beginning of 1890, at the commencement of a third voyage to the Pacific, that he was taken ill at Sydney-an illness which terminated fatally June 21, 1897. He passed away quietly in his sleep.

Abercromby had, from a very early period, paid much attention to observational meteorology. In his "Seas and Skies in many Latitudes," observations are recorded which he must have made during his military service in

We get

RA

HON. RALPH ABERCROMBY. ALPH ABERCROMBY was born in 1842, and was the youngest son of the third Lord Abercromby. His mother was a daughter of Lord Medwyn, a Lord of Session in Edinburgh. Several of his immediate relatives had been eminently distinguished. His great-grandfather, Sir Ralph Abercromby, who died in 1801, in the moment of victory, at the Battle of Alexandria, had served his country with brilliant distinction, in the West Indies Trinidad) and at the Helder.

As soon as the news of Sir Ralph's death reached England, and in commemoration of his services, a barony was conferred upon his widow, with remainder to his

sons.

Of these sons the second became Sir John. He was in the service of the East India Company, and took the Island of Mauritius in 1810. Another was Speaker of the House of Commons in 1835, and was created Lord Dunfermline.

Ralph was never robust, even as a boy. He went to Harrow, and soon was obliged, owing to delicacy, to leave the school. He had, however, shown signs of great promise by taking a double remove after his first term.

In June 1860 he was gazetted to the 60th Rifles, and four years later obtained his lieutenancy and joined the Fourth Battalion at Quebec.

The War of Secession was then at its height. Abercromby obtained leave and visited the scene of action. He took with him letters to General Grant, and was well received, but he did not happen to be present at any of the great battles.

At the beginning of 1866 he entered the Staff College, having passed in without "cramming," but his health soon broke down there. Two visits to Kreuznach produced no benefit, and in 1869, to his great regret, he felt himself obliged to give up his commission.

In later years he twice was sent on a voyage round the world, in hopes of restoration to health; and it was

the new classification of clouds which he, in conjunction with Prof. Hildebrandsson, of Upsala, proposed, and which was adopted by a majority of votes at the International Meteorological Conference of Paris in September 1896.

His published books were: "Principles of Forecasting by means of Weather Charts," 1885, published by authority of the Meteorological Council; "Weather, a Popular Exposition of the Nature of Weather Changes," 1887 (International Scientific Series); "Seas and Skies in many Latitudes," 1888. In addition he brought out many papers which appeared in various journals and periodicals, such as the Proceedings of the Royal Society, the Journals of the Royal and of the Scottish Meteorological Societies, as well as in NATURE, Good Words, &c. Fifteen papers are down to his name between 1873 and 1884 in the Royal Society Catalogue of Scientific Literature.

From his sick bed in Sydney he showed his great interest in the advancement of the science by making grants of money for the production of essays on meteorological subjects. Three of these have been published: "On Moving Anticyclones in the Southern Hemisphere," "On Southerly Bursters," and "On Types of Australian Weather."

Abercromby retained to the very last the power of making and keeping friends. This was in great measure due to his loyal and affectionate nature, which neither distance nor illness could impair. Those who were with him during his last suffering months bear witness to the patience and gentleness, which were as conspicuous under the trials of severe pain as they had been when he was in full possession of his faculties.

His lot was indeed a hard one. He had first to bear the heavy disappointment of enforced resignation of a profession which he loved, and in which his prospects seemed so brilliant, and then he had to sustain the strain of more than twenty years of impaired and gradually failing health.

He leaves behind him the memory of a warm unselfish friend, cut off in a distant land, far from his kith and kin. R. H. SCOTT.

THE

REV. SAMUEL HAUGHTON, M.D.

announcement of the death of Dr. Haughton has been received with the deepest regret in various scientific circles, and by his numerous personal friends and acquaintance attracted to him by his sturdy honesty, unselfishness, and geniality of disposition. He was born in Carlow in 1821. After a distinguished undergraduate career in Trinity College, Dublin, he was elected Fellow thereof in 1844. He held the Professorship of Geology from 1851 to 1881, in which latter year he was co-opted Senior Fellow of the College. He was admitted F.R.S. in 1858. The Universities of Oxford, Cambridge, and Edinburgh signified their appreciation of his merits by conferring on him the honorary degrees of D.C.L. and LL.D., respectively. Having taken the degree of M.D. in his own University in 1862, he was made Registrar of the Medical School there, and applied himself with his usual energy and activity to the reorganisation of that School; thereby raising it to its present condition of high efficiency. He was elected a Governor of Sir Patrick Dun's Hospital, which is connected with the

in

A

It

University, and there made his presence as beneficially felt in the management of the institution as it was in that of the School. We may take this opportunity of noting that, as the result of his experience in such work, he wrote many papers on medical subjects in various publications, and that the honorary degree of M.D. was conferred upon him by the University of Bologna. He represented the University of Dublin on the General Medical Council, from 1878 to 1896, and took a prominent and useful part in the proceedings of that body. Dr. Haughton displayed remarkable versatility of intellect. The record of his scientific work is to be found principally in his numerous papers in the publications of various scientific societies, and scientific periodicals. We may instance those of the Royal Society, the Royal Irish Academy, the Geological Society of London (of which he was a Fellow) and that of Ireland, the Royal Dublin Society, the Cambridge and Dublin Mathematical Journal, NATURE, the Philosophical Magazine, the Natural History Review, the American Journal of Science, the British Association, &c. Among the great variety of subjects treated we may mention his discussion and calculation of the tides in the Arctic seas from the observations of voyagers, and also of the tides round the coast of Ireland, founded upon observations made under the direction of the Royal Irish Academy. He paid much attention to the granites of Ireland. favourite subject with him was animal mechanics. might have been better for his future name, though perhaps not for science in general, if he had bestowed his powers more on the production of treatises on fewer subjects. His work on the "Principles of Animal Mechanics" (London, 1873) makes us feel this. That book was the outcome of observations, experiments, and calculation extending over several years. It includes results published in various papers on different parts of the subject, contributed to the Royal Society and the Royal Irish Academy, and in lectures delivered by him before the Royal Institution in London. The important "Principle of Least Action" is brought frequently into view in his discussion of various details of the vertebrate muscular economy. A complaint, which, however, is unavoidable in this case, has been brought against this book; viz. that many anatomists would not be able to follow the mathematics, and many mathematicians would not have sufficient command of the anatomical points, there presented. His " Lectures on Physical Geography," 1880, printed in the Dublin University Press Series, are marked by his usual power and originality. We shall only allude to his "Manual of Geology," and to the numerous books on elementary science written by him and Prof. Galbraith in conjunction, some of which have had a large circulation. Trinity College, Dublin, will long mourn the vacancy left by him as a gifted son, an able administrator, and an active participator in her work of teaching. The Royal Irish Academy will feel his loss to a very special degree. He joined that body in 1845, and contributed to it most of his principal scientific papers. The Academy presented to him its Cunningham Medal, in 1848, for his "Memoir on the Equilibrium and Motion of Solid and Fluid Bodies." He was for many years a most valued member of its Council, and was President of it from 1886 to 1891. We must not forget to mention that he was for just twenty years the efficient Secretary of the Royal Zoological Society of Ireland with its Zoological Gardens, at a time when the finances of the Society were in a less satisfactory condition than at present, and it is acknowledged that, on more than one occasion, he was the means of saving the Society from shipwreck by his energy and resource. It is very rarely indeed that we meet with a man of so remarkable an individuality, and endowed with such varied powers of working in both practical and scientific lines of usefulness.

C.

NOTES.

Ar a meeting of the general committee of the British Association recently held, Sir W. Crookes, F.R.S., was elected President for 1898. It was decided that the meeting in Bristol shall open on September 7, 1898.

THE Executive Committee of the International Congress of Zoology, which, as has already been announced, will be held at Cambridge in August next, has recently been appointed, and is composed as follows:-President, Sir John Lubbock; VicePresidents, the Vice-Chancellor of the University of Cambridge, Dr. W. T. Blanford, Sir W. H. Flower, the President of the Linnean Society, Prof. Ray Lankester, Prof. A. Newton, Dr. P. L. Sclater, the President of the Entomological Society, Sir William Turner, and Lord Walsingham; Treasurers, Prof. S.

J. Hickson and Dr. Sclater; Secretaries, Prof. F. Jeffrey Bell, Mr. G. C. Bourne, and Mr. A. Sedgwick; Ordinary Members, Dr. Gadow, Mr. F. D. Godman, Lieut.-Colonel Godwin-Austen, Sir G. F. Hampson, Dr. S. F. Harmer, Prof. Howes, the Hon. W. Rothschild, Mr. H. Saunders, Prof. Seeley, Dr. D. Sharp, Mr. A. E. Shipley, Prof. C. Stewart, and Dr. H. Woodward. The official address of the Congress is, by the courtesy of the Zoological Society, 3 Hanover Squ are, London, W.

THE interesting ceremony took place on Monday afternoon last, at the Michael Faraday Board School, Faraday Street, Walworth, of unveiling a bust of Michael Faraday. The bust, which is of white marble, was presented to the school by the managers of the Royal Institution of Great Britain, and is a copy of the original bust executed by Matthew Noble. It stands upon a pedestal of Aberdeen granite four feet in height, and has been placed in the boys' hall of the school. On the wall immediately behind the bust a large brass tablet has been affixed, bearing the following inscription :-" Michael Faraday, natural philosopher, D.C.L., F.R.S., born at Newington, Surrey, September 22, 1791. He was a patient student, an eloquent expounder, and a brilliant illustrator of the laws of nature. Fullerian Professor of Chemistry in the Royal Institution of Great Britain, 1833 to 1867. Faraday's noblest monument is his Experimental Researches in Electricity and Magnetism' from 1831 to 1851. He died at Hampton Court Green, August 25, 1867, and was interred in Highgate Cemetery." Sir J. Crichton Browne, F.R.S., unveiled the bust, and expressed his pleasure at being permitted to unveil this statue of a great man who had spent a long life in unveiling the hidden mysteries of nature. He hoped the sight of that bust would be an inspiration to the children, and that they would learn who Faraday was and what he did. He suggested that one day every year should be set apart in the school in memory of Faraday, when some part of his work should be explained.

PROF. OLIVER LODGE will deliver the first of a course of six Christmas lectures (specially adapted to young people) on "The Principles of the Electric Telegraph," at the Royal Institution on December 28. The remaining lectures will be given on December 30, 1897, and January 1, 4, 6, 8, 1898.

THE Jubilee Medal has been presented to Sir Robert Ball, the President of the Royal Astronomical Society.

Science announces that the Austrian steamship Pola has again gone to the Red Sea for scientific explorations, and will this year cover the ground between Dschedda and Aden. Dr. Franz Steindachner, the ichthyologist, has charge of the zoological work, and observations will also be made in physical oceanography.

THE meeting of the American Psychological Association will be held this year at Cornell University, Ithaca, under the presidency of Prof. Baldwin, the sessions beginning on December 28.

ACCORDING to the Allahabad Pioneer Mail, the Ceylon Survey Department is about to start on a cadastral survey of the Crown lands and lands of doubtful ownership in the island, on a scale of ten inches to the mile, and a topographical survey on a scale of one inch to the mile. It is estimated that the cadastral survey will occupy the ordinary staff for about twentyfive years. The triangulation and topographical survey, which will embrace the whole island, will, it is expected, be completed in five or six years. It is stated that at the present time there is no trustworthy map of Ceylon in existence; that there is no contour map of the island of any description, and that the present so-called map is a compilation from Colonel Fraser's map (now nearly 100 years old), and contains errors so numerous and gross as to make it useless. Hence the new surveys to which reference is made.

THE Indian Section of the Pasteur International Memorial Fund has just forwarded a further contribution to the above of 177. 35. 6d., bringing the total amount subscribed in India up to the handsome sum of 4607. In a letter to Prof. Percy Frankland, F.R.S., Surgeon Major-General Cleghorn mentions that "the original subscription list contains the names of a goodly number of natives who have subscribed small sums."

WE are glad to notice that Surgeon-Major A. M. Davis is to be attached to the office of the Principal Medical Officer in India, as a tentative measure, for one year, for the purpose of carrying out bacteriological and sanitary investigations. We hope the office of bacteriologist and sanitary investigator will soon be a permanent one. It is also stated that the Madras Government has applied to the supreme Government for the appointment of a bacteriologist, and has received a sympathetic answer, the suggestion of the Government of India being that the present Professor of Hygiene at the Medical College should be appointed Professor of Bacteriology.

Sir

FURTHER particulars of the arrangements for the forthcoming meeting of the Australasian Association have reached us. James Hector, the president of the geographical section, has announced as the probable subject of his presidential address

appearance of Native Races in general, and of Fijians in particular," by H. H. Thiele; "The Colour of Flowers, and its Influence on Bee Life," by Albert Gale; "Notes on the Wax of Ceroplastes rubens," and "On the Colouring Matter of Eris cocci eucalypti," by E. H. Gurney. A long list of excursions has been prepared, and at a recent meeting of the Council it was unanimously decided that scientific societies in other colonies should be invited to send non resident delegat to the Sydney session; and that members of the British, American and foreign associations, non-resident in Australasia, who attend, should be admitted free.

66

THE following science lectures will be delivered at the Imperial Institute on the dates mentioned :-On November 19, Three Years in the Arctic," by Mr. F. G. Jackson; on November 22, "Electric Balloon Signalling applied to Scientific Exploration in Arctic and Antarctic Expeditions," by Mr. Eric Bruce; on November 29, "The Wild Kafirs of the Hindu Kush,” by Sir G. S. Robertson; on December 6, "The Mineral Resources of British Columbia and the Yukon," by Mr. A. J. McMillan; on December 13, "Canada's Metals," by Prof. W. C. Roberts-Austen ; on December 20, "The Petroleum Sources of the British Empire," by Mr. Boverton Redwood.

THE International Congress on the Protection of Birds, opened at Aix-en-Provence on November 9, and arranged by the Ligue Ornithophile Française, of which M. Louis-Adrien Levat is the president, was concluded on Saturday last. The protection of insectivorous birds useful to agriculture was the chief matter discussed, and it was decided to forward to the Governments of Europe, through the French Minister of Foreign Affairs, the resolutions which were formulated. Public educational bodies are also to be approached in order to obtain, if possible, the serious consideration of this important subject by schoolmasters and Government school inspectors. Numerous French and Italian agricultural, horticultural, and sporting societies were represented at the Congress, and delegates from the Selborne Society and the Society for the Protection of Birds were also present.

THE late Mr. W. Bolitho of Penzance, for thirty-five years treasurer of the Royal Geological Society of Cornwall, bequeathed 500l. to the trustees of that Society, the yearly income accruing from which was to be applied to the purchase of a gold medal, "to be called the William Bolitho Medal, to be awarded to such member of the said Society, whether Ordinary, Honorary, or Associate, whose attainments, labours, and discoveries in President and Council of the said Society, best deserve reGeological or Mineralogical Science shall, in the opinion of the November, 1896, to Prof. Robert Etheridge, in recognition of cognition." "his age, his great attainments, and his life-long labours for the benefit of science." The second award was made on the 9th inst. to Mr. Howard Fox, of Falmouth, in recognition of of his having brought to light the radiolarian beds of the southhis various discoveries in the field geology of Cornwall, and west of England.

The first award of this medal was made in

THE Electrical World (New York) states that the National Museum at Washington has just been enriched by a very valuable and interesting collection, comprising the private papers of the late Mr. Cyrus W. Field relating to the laying of the first

Mr Field worked out the idea of laying the cable, and many other things of interest pertaining to the project. The correspondence and autograph copies of telegrams sent by Mr. Field to the President of the United States and other eminent persons are included. The globe, which was constructed in London, and on which Mr. Field traced the course of the cable

to be laid from Newfoundland to Ireland, forms an attractive object of the collection. It is about 18 inches in diameter, on a stand, with a magnetic compass underneath, and shows many signs of hard usage. The journal kept by Mr. Field and notes of deep-sea soundings set down by him and officers of the Great Eastern, which laid the cable, are part of the collection. Mr. Field's private library, with all the literature relating to the work of laying the cable, forms another part. There are also copies of medals presented to Mr. Field by Congress and the French Government, engrossed resolutions passed by public

bodies in the United States and in Europe, a cane from the

wood of the Great Eastern, &c., as well as cases containing

sections of the first Atlantic cable.

THE Paris correspondent of the Times gives particulars of the trial trip at Mantes of the electric locomotive devised by M. Heilmann. The train, which was composed of twelve carriages and a luggage van, and carried 250 persons, weighed about 150 tons. The object of the trip was not to make a trial of speed, and the train journeyed at the rate of only eighteen miles an hour; the experiment seems, however, to have been considered a great success, and testimony is borne to the ease and regularity of the movement of the train. Great things are hoped from this invention, no less than the conveying of a train weighing 300 tons at the speed of sixty-two miles an hour being looked forward to. The Heilmann engine draws a closed tender containing a steam engine of the Pilon pattern, which works the dynamos producing electricity. The motive power is transmitted directly to the eight wheels, which are only one metre five centimetres in diameter. The consumption of coal by the engine is less than that of an ordinary engine, so that the locomotive can go greater distances with fewer and shorter stops for replenishing coal and water. It will, of course, light up the carriages by electricity, and it is thought that the electric will supersede the air brake.

A LECTURE on "Microscopic Observations on Deterioration by Fatigue in Steel Rails," was given on Monday, the 8th inst., before the Sheffield Society of Engineers and Metallurgists, by Mr. Thomas Andrews, and is reported in the Sheffield Daily Telegraph, from which we give a condensed report as follows:The earlier part of the lecture was occupied with the 'consideration of the external stress and disintegrating forces imposed on rails, and a large number of illustrations of the state of the wearing faces of rails which had endured the stress of wear for known periods and under known conditions of main line service were given. The gradual development of lines of transverse weakness, indicating the danger from minute cracks, and showing the influences of internal micro flaws in assisting the loss of strength due to vibratory stress were then traced. The effects also of varied chemical compositions on the physical properties and strength of steel rails were also considered, and illustrated by numerous micro-sections and micrographs. The lecturer referred to his recent researches on another serious cause of the loss of strength in rails arising from occasional segregation of the chemical constituents and impurities in steel rails, and offered suggestions for the prevention of this evil. He further referred to the light thrown on this question by recent microscopic researches on the structure of gold and other metallic alloys. The effects of the secondary crystallisation of iron recently observed by the lecturer were also illustrated. Reasoning from the results of his research on the microscopic structure, chemical composition, and physical structure of rails of satisfactory long life, Mr. Andrews indicated the conclusions he had arrived at as to the specification for modern rails best calculated to ensure durability and safety for main line services. The lecturer mentioned that he was still pursuing additional chemical, physical, and microscopical researches on the important question

on the loss of strength in steel rails by reason of use, and expressed the hope that valuable results in the interests of the public safety would result.

AT a meeting of the Nottingham Naturalists' Society on November 9, the newly-elected president, the Rev. A. Thorn

ley, delivered a thoughtful address on "The Work of a Natural History Society." In the opinion of the president, the functions of a Society such as theirs should embrace at least the foltection. The speaker, in the course of his remarks, regretted lowing objects: instruction, stimulation, field-work, and pro

that the study of entomology has up to the present been to a

large extent neglected in the county of Nottingham, but stated

there were signs of improvement in this direction, as during the past year their Coleoptera list had been largely augmented by the labours of several members of their Society.

THE so-called "fruit cure," although not much heard of in this country, is well recognised at various places on the continent, where so-called grape-cure stations have been established. In a recent number of Modern Medicine and Bacteriological Review there is an interesting article on the subject, in which the historical side of the question is dealt with. Thus we are told that many medical authorities in the tenth century become enthusiastic in their writings over the remarkable curative virtues

of grapes, whilst a certain Van Swieten, of a more modern date, is said to have "recommended in special cases the eating of twenty pounds of strawberries a day." The same gentleman also reports a case of phthisis healed by strawberries, and cites cases in which maniacs have regained their reason by the exclusive use of cherries as food! These instances rather savour of the miraculous; but there is no doubt that the so-called grape-cure, for indigestion and other evils, is carried on in many places on the continent, and that people betake themselves to Meran, Vevey, Bingen, or to Italy and the South of France with the intention of devoting six weeks to the cure, during which time they are expected to have gradually accomplished the feat of consuming from three to eight pounds of grapes daily as the case may be. Grapes are said to exercise a salutary action on the nervous system and to favour the formation of fat, that is to say, when fruit of good quality is employed; if the grapes are not sufficiently ripe, and are watery and sour, the patient may lose Dr. Kellogg, Director of the rather than gain in weight. Sanitarium Hospital and Laboratory of Hygiene at Battle Creek, Mich., is of opinion that the valuable results obtained by a fruit diet in cases of biliousness which he has observed are due to the fact that noxious germs habitually present in the alimentary canal do not thrive in fruit juices.

THE Board of Trade report for 1897 on the sight tests used in the mercantile marine shows that of the fifty-six candidates who failed in colour vision in 1896 twelve were examined on appeal, of whom five passed and seven were rejected. The number of officers already in possession of certificates who, on coming up for examination in 1896, failed to pass the sight tests, was twelve-one master, five mates, and two second mates failing in colour vision, and one mate and three second mates failing in form vision. Two of the mates who failed in colour vision appealed and passed, and one of the second mates who failed in form vision passed on re-examination. The percentage of failures to pass the colour tests was 102, a percentage almost exactly the same as that obtained in former years, before the introduction of the wool test. The most extraordinary point in the report is the great number of normal sighted persons who were rejected as colour blind; no less than 416 per cent. of those who appealed passed. This state of things, says the British Medical Journal, we may expect to continue until properly qualified medical men are employed as examiners, and a trustworthy test is used.