Special features of the volume are the number and quality of the illustrations. There is a good index.

The work is an exceedingly valuable contribution to anthropological literature, indispensable for the student of primitive beliefs and ceremonial. SIDNEY H. RAY.

THE

WHEN

means

EVOLUTION OF THE PETROGRAPHICAL MICROSCOPE. HEN Henry Clifton Sorby laid the foundation of the science of microscopical petrology, in the year 1851, the instrumental at his command were of the simplest kind; his microscope had attached to it two Nicol-prisms, one above the eye-piece and the other below the stage, the latter being capable of rotation, thus rendering it possible to study the sections of minerals in rocks by plane polarised light. Then, as is so often the case, necessity became "the mother of invention," and Sorby himself, as well as several of his followers, devised additions to their microscopes which converted them into more useful instruments for investigating the optical properties of minerals, as seen in thin sections of rocks. The designers of these improvements were, of course, dependent on the able makers of optical instruments for putting their suggestions into practical form.

In the year 1876 the late Prof. Rosenbusch, of Heidelberg, who had been led to the microscopical study of rocks by Heinrich Fischer, one of the earliest pioneers in this branch of research in Germany, described "a new microscope for mineralogical and petrological researches.' The chief features in this microscope were an accurately graduated, revolving stage, with verniers, and a complex nose-piece enabling the objectives to be rapidly changed. About the same time MM. Fouqué and Michel Lévy-with the co-operation of M. Emile Bertrand-had also turned their attention to the improvement of this class of instruments. The eminent optical instrument-maker of Paris, M. A. Nachet, carrying out their designs, constructed a microscope which embodied many advantageous features for petrographical work. In this instrument the necessity for the troublesome centring arrangements, for keeping an object on the cross-wires of the field of view, is got rid of by dividing the tube into two portions moving independently, the upper section carrying the eye-piece, analyser, and some accessory apparatus, and the lower attached to the finely graduated revolving stage bearing the objectives; these latter are easily changed by moving in a slide with spring-catch. Another important addition to the instrument which we owe to the French petrologists is the series of converging lenses with a magnifying lens above, by which interference figures may be viewed in the thin sections of minerals in rock-slides. It is true that these interference figures are only partial ones, but by the aid of diagrams supplied by the authors of

the method their interpretation possible.

rendered

Outside France, the Nachet instrument would not appear to have come into very general use, a fact which is perhaps accounted for by the rather cumbrous arrangements necessitated by the division of the tube. In this country an arrangement having the same object has been devised by Mr. A. B. Dick, and has found much favour with many petrologists. It consists in having the rotating, polarising and analysing prisms so connected that they can revolve together, while the stage is fixed. The forms of the ordinary and Dick types of petrographical microscope, as employed by the officers of the Geological Survey of Great Britain are illustrated in Figs. 1 and 2.

Still more recently the celebrated Russian crystallographer, Féderow, has devised a form of the mineralogical and petrographical microscope, in which the crystal or section to be examined is carried on a stage which is capable of movement and inclination at exactly measurable angles, by which means very important optical determinations may be made. Instruments constructed on Féderow's plan are made by the Société Genevoise pour la Construction d'Instruments de Physique et de Mécanique, 87 Victoria Street, London, S. W.

As a matter of course, all the improvements in the mechanical and optical arrangements in microscopes introduced during the last fifty years have been made available for the instruments constructed for mineralogical and petrographical work. With the addition of many pieces of accessory apparatus, such as sections and wedges cut in definite directions from the crystals of various minerals, stage goniometers, and special arrangements for stage-movement, the instruments of this class have now become, as will be seen from the figures, more and more complicated as the refinement of methods has increased.

Not less important than these elaborate instruments employed in research are the simpler forms used in elementary and advanced geological teaching, which must necessarily be produced at much smaller cost. There are also special petrographical microscopes made, which are adapted for projection purposes in lecture-theatres, for photographic work, for examining crystals and sections while being heated and cooled, and for studying the development of crystals in solutions and fused materials. and fused materials. Examples of many of the types of petrographical microscopes are exhibited in the Science Museum at South Kensington.

As a direct offspring of the petrographical microscope, we may refer to the instruments now so extensively employed in metallographical researches. In 1864 Sorby, while studying sections of meteorites, for the purpose of comparing them with terrestrial rocks, was led to examine the grains of nickel-iron in the "sporado-siderites," after they had been etched, by reflected light. It occurred to Sorby that the same method of study might with advantage be employed in the case

Cryptogamic botany. He also published a fungus flora of Australia and many papers of scientific importance, besides innumerable minor articles. His industry is further attested by the presence in the Kew collections of about 25,000 of his drawings of fungi. During later years, especially, he wrote popular books, and also turned his attention to other fields of cryptogamic botany. After his retirement in 1892 Cooke retained his interest in fungi, and until 1904 attended the annual fungus foray of the Essex Field Club. Recently his eyesight failed, though his mind remained keen and active. He was honorary M.A. of Yale, and LL.D., and in 1903 he had the honour of being awarded the gold medal of the Linnean Society. A. D. C.

NOTES.

THE King has been pleased to approve of the following awards this year by the president and council of the Royal Society :-A Royal medal to Prof. E. W. Brown, F.R.S., for his investigations in astronomy, chiefly in lunar theory; a Royal medal to Prof. W. J. Sollas, F.R.S., for his researches in palæontology, especially in the development of new methods. The following awards have also been made by the president and council:-The Copley medal to Sir Joseph Thomson, O.M., F.R.S., for his discoveries in physical science; the Rumford medal to the Rt. Hon. the Lord Rayleigh, O.M., F.R.S., for his numerous researches in optics; the Davy medal to Prof. W. J. Pope, F.R.S., for his researches on stereochemistry and on the relations between crystalline form and chemical constitution; the Darwin medal to Prof. E. B. Poulton, F.R.S., for his researches in heredity; the Hughes medal to Prof. J. S. Townsend, F.R.S., for his researches on electric behaviour of gases.

NATIONAL regret at the death of Lord Roberts on Saturday last, as the result of a chill caught while on a visit to France to see the Indian troops, is shared by men of science. Throughout his career Lord Roberts stood for scientific organisation and individual efficiency; and to the last day of his life he was concerned with undertaking useful services for his country. In the field his success was the fruit of careful forethought, boldness, and vigour; when an administrator he laid stress on the encouragement of intelligence and initiative among soldiers of all ranks; and after his retirement from active service he devoted the remainder of his days to advocating the encouragement of rifle shooting as a national pursuit, and the establishment of a system of obligatory physical training. He saw the needs of his country and did his best to educate public opinion in favour of a remedy for them. In Lord Roberts the attributes of duty and self-sacrifice were represented at their highest, and the whole Empire mourns that he has now passed into silence.

THE Council of the Physical Society of London has decided not to hold the annual exhibition of physical apparatus this year.

THE eighty-ninth Christmas course of juvenile lectures, founded at the Royal Institution in 1826 by

Michael Faraday, will be delivered this year by Prof. C. V. Boys, his title being “Science in the Home."

We regret to learn of the death, at sixty-five years of age, of Dr. J. Borgmann, professor of physics in the University of Petrograd, and author of various works on electricity and magnetism.

We regret to announce that Prof. August Weismann, professor of zoology in the University of Freiburg-im-Breisgau since 1867, foreign member of the Royal Society, and of world-wide distinction as a biologist, died on November 5 at eighty years of age.

Ar the annual meeting of the London Mathematical Society, held on November 12, the De Morgan medal was presented to Sir Joseph Larmor in recognition of his researches in mathematics and mathematical physics.

A FAIRLY strong earthquake was felt over Jamaica on October 15 (see NATURE, vol. xciv., p. 207). A month later, on November 15, two other shocks were felt, the first at 12.50 a.m., of considerable force, and lasting seven or eight seconds; the second, a slighter shock, between 8 and 9 a.m. No serious damage was caused by either shock.

MR. W. S. ADAMS, Mount Wilson Solar Observatory, California; Prof. H. Andoyer, professor of physical astronomy in the Sorbonne, Paris; and Dr. F. Schlesinger, director of the Allegheny Observatory, and professor of astronomy, University of Pittsburgh, U.S.A., have been elected associates of the Royal Astronomical Society.

Ir is announced in the London Gazette that the King has appointed Mr. T. H. Warren, president of Magdalen College, Oxford, to be Knight Commander of the Royal Victorian Order, and Mr. C. G. Robertson, fellow of All Souls' College, and senior tutor in modern history at Magdalen College, Oxford, to be Commander.

FOR several years Prof. W. B. Bottomley, King's College, London, has been working on the bacterial treatment of peat; and some results of the investigation have been described in papers presented to the Royal Society and the British Association. The Board of Agriculture has now made a grant of 150l. to the botanical department of King's College in aid of research on the subject of the probable accessory foodsubstances in humus and "bacterised "peat, a condition of the grant being "that reasonable facilities will be accorded to any accredited scientific worker who may desire to undertake investigations in connection with bacterised' peat."

Ar the anniversary meeting of the Mineralogical Society, held on November 10, the following officers and members of council were elected :-President: Dr. A. E. H. Tutton. Vice-Presidents: Prof. H. L. Bowman and Dr. A. Hutchinson. Treasurer: Sir William P. Beale, Bart. General Secretary: Dr. G. T. Prior. Foreign Secretary: Prof. W. W. Watts. Editor of the Journal: Mr. L. J. Spencer. Ordinary Members of Council: Mr. F. H. Butler, Mr. J. P. De Castro, Mr. B. Kitto, Prof. A. Liversidge, Dr. J. J. Harris

Teall, Mr. F. N. Ashcroft, Prof. H. Hilton, Mr. A. Russell, Mr. W. Campbell Smith, Dr. J. W. Evans, Dr. F. H. Hatch, and Mr. J. A. Howe.

Ar a meeting of the council of the British Association, held on November 6, it was resolved :---" That the council of the British Association for the Advancement of Science, at its first meeting in London since the return of members from Australia, desires to place on record its high appreciation of the generous reception given to the members of the overseas party throughout the Commonwealth by representatives of the Governments of the Commonwealth and the States, and by other authorities and Australian citizens generally, on the occasion of the meeting of the association in Australia in 1914. The council hereby expresses its grateful thanks for the hospitality, privileges, and concessions extended so freely to visiting members, and also for the willing and valuable collaboration of all those who undertook so successfully the work of organisation in Australia in connection with the meeting."

By the death of Sir Walter Gilbey at Elsenham Hall, his Essex residence, on November 12, the country is distinctly the poorer, as the deceased baronet had an unsurpassed practical knowledge of horses and horse-breeding, more especially as regards "shires,” hackneys, and ponies. His two little books on these breeds are models of what such works should be, teeming, as they are, with practical and historical information condensed into the briefest possible space. Sir Walter was the founder of the Shire Horse Society, which published its first stud-book in 1880, and held its first show at the Agricultural Hall in 1881. He also took an active part in the establishment of both the Hackney Horse Society and the Hunters' Improvement Society, and he was likewise instrumental in diverting the grants for “Queen's Plates" to the more useful purpose of premiums for thoroughbred sires. He was in turn president of both the Shire Horse and the Hunters' Improvement Society. It may be added that Sir Walter did no less good service for stockbreeding and agriculture in general. He had attained the ripe age of eighty-three years.

AMERICA has lost one of her leading geographers by the death, in his sixty-ninth year, of Mr. Henry Gannett. After graduating at the Harvard Scientific and Mining Schools, he was for a short time an assistant at the Harvard Observatory. From 1872 to 1879 he acted as topographer for the Hayden Survey of the Territories. When the U.S. Bureau of Geological Survey was established in 1879, Mr. Gannett assisted in planning out its work, and from 1882 until his death he held the position of its chief geographer. He was geographer to three decennial censuses and to the Conservation Commission of 1908-9, chairman of the U.S. Geographical Board, and president of the National Geographic Society. His published works included gazetteers of twelve States, the statistical atlases of three censuses, the contour map of the United States, a manual of topographic surveying, and numerous official reports. In an editorial note on his career the New York Evening Post pays him the

tribute that, in spite of the notable results of his own industry, it is as a stimulator of other geographers and map-makers that he chiefly deserves to be remembered.

war.

WE are glad to see again the familiar pages of the Revue Scientifique, the publication of which was suspended at the beginning of August, on account of the The number which has just reached us is the first to be published since August 1, and it bears the date August 8-November 14. The main part of the issue is made up of the papers upon the nature and treatment of wounds, presented to the Paris Academy of Sciences on August 10 and September 28, and referred to already in our columns. Following these is a translation of the statement signed by German professors as to the cause of the war, with a complete list of signatures, and replies to the manifesto made by the Academy of Sciences, the French Academy, Institute of France, representatives of Russian art, literature, and science, and British scholars. William Ramsay's article on "Germany's Aims and Ambitions' is translated from NATURE of October 8, and there is also a translation of the letter from Dr. C. W. Eliot, president of Harvard University, published in the New York Times of October 2. We trust that our contemporary will find it possible to continue its weekly issue as formerly. La Nature, which suspended publication on August 1, has not yet started a re-issue.

Sir

ACCOUNTS of the valuable work which the officers of the Royal Army Medical Corps have accomplished in Boulogne for our wounded are given in the Times of November 10 and 14. The description of the Boulogne hospitals affords a clear picture of the very best sort of hospital administration and practice, thanks to Colonel Lynden Bell, Sir Almroth Wright, and all members of the staff and nursing staff of each hospital. From the potent and unfamiliar infections of the Belgian soil, which has been under intensive cultivation and incessant manuring for a quarter of a century, comes a host of troubles. The majority of the wounds are contaminated at the moment of infliction. The usual ritual of the antiseptic and aseptic method, perfect in time of peace for this or that formal operation of surgery in a placid, well-appointed hospital, may not suffice for the treatment of men wounded in the trenches by shrapnel or shell fragments, their clothes and their skins caked thick with mud, and that mud carrying dangers of its own. Against the risk of tetanus, we have the protective use of the tetanus antitoxin; against gangrene, we have the injections of oxygenated water, and the later “open-air treatment of the wound, and there are other methods by which science is used to reduce suffering at the Boulogne hospital base and elsewhere.

IN Man for November, Prof. Carveth Read examines the question of the differentiation of man from the anthropoids. He dwells on the importance of the change from a vegetable to a carnivorous diet on the habits, functions, and structure which distinguish man from the higher apes. This change of diet, he urges, explains the adaptation of our species to a ground-life and to a world-wide diffusion. This in