The fragmental material of the rim consists of the débris of the strata in which the crater has been formed, the blocks being piled one upon another in the utmost confusion. Further, there are many millions of tons of pulverised sand-grains, much of the material being an impalpable powder. It constitutes a great part, not only of the rim, which is three miles in length round the base, but also of the bottom of the crater, for it has been found by means of bore-holes to extend to a depth of more than 850 feet.

The masses of meteoric iron, being of pecuniary value as specimens, have been much sought for, and masses small and large, amounting altogether to about fifteen tons, have been found among the upper blocks on the rim, and on or near the surface of the surrounding plain in all directions from the crater; none have been found within the latter. Several masses weigh from 600 lb. to more than 1000 lb. Mr. Gilbert states that some of the iron has been found outside the range of the rock débris, one large mass being as much as eight miles distant from the crater. There have also been found lumps of oxide of iron, in great quantity and having a similar distribution to that of the metal. Mr. Gilbert (and also Dr. Foote) regarded them as also being of meteoric origin, and as perhaps having resulted from the weathering of a particular constituent of the meteorite, namely, the protosulphide of iron; but Mr. Barringer and Mr. Tilghman have found that they contain much nickel, and that many of them consist internally of magnetic oxide of iron, sometimes itself containing a nucleus of meteoric iron. Mr. Barringer, like Dr. Foote, suggests that the magnetic oxide resulted from the combustion of the iron when the meteorite was travelling through the air, but in the opinion of the present writer all the oxide, magnetic or not, is a result of weathering. There has been plenty of time for this action, for cedars now 700 years old are growing on the rim of the mountain. Further, the masses of iron found on the surface of the plain must have penetrated the earth to some depth at the time of the fall, and have been since exposed by denudation of the penetrated material. The authors roughly estimate the fall to have taken place not more than 5000 years ago, perhaps much less.

Though all the masses of iron found in the rim have been got from the surface, lumps of the meteoric oxide have been met with to a depth of 27 feet, and this is of interest because some of them were lying beneath big blocks of sandstone, through which, whether as metal or as oxide, they could not have passed. They must have taken up their present positions at the same time as the blocks themselves. To the present writer it seems probable that they had been buried, possibly a long time, in the upper layers of sandstone, and were ejected with the rock-fragments when the crater was formed, but Mr. Barringer explains them as fragments which had been broken from the asteroid during its passage through the air, had diverged from the path of the meteor, and had while still burning become entangled, and afterwards smothered, among the blocks of sandstone and minute débris projected into the air through the penetration of the earth by the main mass.

As for the enormous amount of pulverised silica, the authors hold that it cannot have been produced otherwise than by the action of an enormous projectile penetrating the sandstone. But it is difficult to see why the crushing of the grains could not have been produced by an enormous pressure of steam, such as must have preceded, according to Mr. Johnson, the formation of the crater. The fol

lowing remark made by the late M. Daubree was published by him in 1879, before Coon Mountain had been heard of, and is also suggestive (" Géologie Expérimentale," part ii., p. 645):-" In the deep and hot portions of the globe, for instance in wilcanic reservoirs, water is present under enormous pressure The pressure of that which forces lava up to the summit of Mt. Etna must certainly exceed too atmospheres. It is therefore quite comparable with the tension developed in the chamber in which these experiments have been made. When water escapes to the surface by narrow fissures in such circumestances, it must bring different substances into state of pulverisation simulating that of volatilis... tion."

Two other observations are relied on by the auth in their support of the asteroidal hypothesis. According to the first observation, obstacles at a great depla and probably of smail size were found to interferwith the boring. They were inferred, chiefly from their hardness and from the difficulty of removal of a magnet let down to the bottom of the bore-hol to be probably metallic iron, and to be parts of the broken asteroid. But the presence of some small masses of iron beneath the crater is to be expected i* all the masses were lying embedded in the sandstone before the crater was formed. Those which were prejected nearly vertically upwards must have fallen back into the large hole and be deep down among the débris. According to the second observation, a stratum at a considerable depth contains small particles of oxide of iron thought to be of meteoric origin The same kind of material is said to occur on the surface of the surrounding country for several miles. The material in which these small particles of oxide are distributed in the crater must either be in situ or have fallen back into the hole in the former cas they cannot be of meteoric origin, for small particles would not have had the requisite penetrative power; in the latter case, it is probable that they were lying near the surface before the steam-explosion, and fell back with the fragmental material into the hole.

It is found as a matter of experience that meteorites on striking the ground have a comparatively sm velocity-only a few hundreds of feet a second. I it possible that an asteroid after passing through the earth's atmosphere could retain a velocity large enough for the production of such a crater? Appl ing a method devised by Schiaparelli and numerical data obtained from artillery experiments, the present writer has made some calculations as to the velocity of a meteoritic ball on reaching the ground, the ball being supposed to have a specific gravity seven times that of water, to have entered the earth's atmosphere at a speed of fifty miles a second, and to have travelled vertically. Neglecting the small additional velocity due to the action of gravity for the few seconds of flight, and the diminution of size of the ball during the flight, the numbers are as follows:Final velocity in metres

Radius of ball in metres

admission by the root-hairs, though he thought the parasite was a myceloid fungus, whereas it has since been proved to be a bacterium. The whole subject was admirably resumed by him in an article contained in vol. i. of the Annals of Botany (1887-8), of which periodical he was one of the founders. The same volume opens with a paper by him and Mr. T. Dunlop on the histology and physiology of the fruits and seeds of Rhamnus, perhaps one of the best of his researches, in which it is shown that the yellow pigment (rhamnin), obtained from the fruits for dyeing purposes, is formed by the decomposition of the glucoside (xanthorhamnin) contained in the pericarp by a ferment existing principally in the testa of the seed. In the second volume of the Annals (1888-9) there is an elaborate paper, "A Lily-disease," the chief point of interest being the discovery that the fungus (Botrytis) penetrates the cell-walls of the host by means of a ferment (since termed cytase) secreted at the tips of the hyphæ. Ward's views on parasitism were further developed in his paper "On some Relations between Host and Parasite in certain Epidemic Diseases of Plants" (Proc. Roy. Soc., vol. xlvii., 1890), which gained the honour of selection as the Croonian Lecture for that year. Passing over with mere mention the papers on Craterostigma (Trans. Linn. Soc., 1890) and on the Ginger-beer Plant (Phil. Trans., 1892), I come to his most laborious achievement, a series of reports on the bacteriology of the Thames, presented, in conjunction with Prof. Percy Frankland, F.R.S., to the Water Research Committee of the Royal Society in the years 1893-6. It is difficult to form any adequate conception of the unfailing assiduity necessary to the working out, as Ward did, of the life-histories of the no less than eighty different bacterial organisms that he found in the river, nor is it possible here to give an account of these voluminous documents, a résumé of which, so far as his share of the work is concerned, was given by him in the fifth report (Proc. Roy. Soc., vol. Ixi., 1897). He had proved his fitness for this difficult task by his paper "On the Characters or Marks employed for Classifying the Schizomycetes "in the Annals of Botany, vol. vi., 1892, and the accomplishing of it gave rise to such interesting parerga as the papers "On the Action of Light on Bacteria" (Phil. Trans., 1895), "A Violet Bacillus from the Thames," and "Some Thames Bacteria" (Ann. Bot., xii., 1898). The first of these papers is of considerable importance in that the bactericidal effect of light, whether of the sun or of the electric arc, is conclusively demonstrated, and is shown to be confined to the more highly refrangible rays of the spectrum.

Ward was a regular attendant at the meetings of the British Association for the Advancement of Science, and was president of the botanical section at the meeting in Toronto in 1897. His address on that occasion dealt with a subject that was always in his mind, the economic significance of the fungi, of which he gave a characteristically exhaustive account. In fact, all his subsequent work was the expression of this idea. Thus in 1898 (Phil. Trans.) he published an investigation of Stereum hirsutum, the fungus that attacks the wood of the oak, having succeeded, by means of pure cultures, in tracing its life-history from the spore to the fructification, and he did the same for Onygena equina, the horn-destroying fungus (Phil. Trans., 1899). He then entered upon what was destined to be his last line of research, the investigation of the Uredines or Rusts, with an energy that was remarkable even for him; but it was not until 1902 that the publication of the results began, so long and so numerous were the experiments from which they were drawn. The first paper on the sub

ject was read before the Cambridge Philosophica Society in January, 1902 (Proc., vol. xi.), treating of the physiological races of these fungi, with speci..! reference to the Brown Rust of the Brome-grasse Having shown that certain species of Bromes can only be attacked successfully by certain forms or breeds of the Rust, he arrived at the striking coo clusion that "the capacity for infection, or for resist ance to infection, is independent of the anatomica! structure of the leaf (of the Grass), and must depend upon some other internal factor or factors in the plant. Two papers published later on in the year (Proc. Roy. Soc., vols. Ixix. and lxxi.) discuss the question, with an answer in the negative, as to whether or not susceptibility to infection depends upon the nutritive conditions offered by the host to the parasite, the foregoing conclusion being reasserted thus:-"All the evidence points to the exist ence, in the cells of the fungus, of enzymes or toxins. or both, and in the cells of the host-plant of antitoxins or similar substances, as the decisive factors in infection or immunity, although I have as yet failed to isolate any such bodies." In the meantime yet another paper had appeared in the Annals of Botans (vol. xvi., June, 1902) confirming his previously expressed conviction that differences in details of anatomical structure do not afford any explanation of the relations between the Bromes and their Rusts His last paper on this subject is that dealing with the adaptive parasitism of the Brown Rust (Annale Mycologici, vol. i., 1903), in which he developed the interesting idea of the existence of what he termed "bridging species." The idea is briefly this, that although it is generally true that the adapted raceof the parasitic fungus are restricted to groups of closely allied host-species, there do occur host-species which serve as intermediaries in the passage of the parasite from members of one section of the hostgenus to those of another section.

Incidentally, a controversy arose between Ward and Prof. Eriksson, of Stockholm, with reference to the "mycoplasm-theory" of the latter. of the latter. In order to account for the occurrence of sudden and widespread epidemics of Rust, Eriksson had assumed the persistence in a dormant state, within the tissues of the host-plants, of a combination of the protoplasm of the fungal hyphae with that of the host, which he had described and figured and had called "mycoplasm. As stated in his paper on the question (Histology of Uredo dispersa, &c., Phil. Trans., Ser. B, vol. cxcvi.. 1903), Ward was unable to confirm Eriksson's observ ations, and regarded his assumption as unnecessary. One of the most interesting discussions in Section K during the Cambridge meeting of the British Assoc ation, 1904, was that in which the pros and cons of this theory were urged by the two protagonists. Their views were subsequently published, side by side, in the Annals of Botany (vol. xix., January, 1905).

At this point the record of his work as an investigator abruptly ends, when great things might still have been anticipated, and it might well be deemed sufficient to have occupied all the time and energy at his disposal. However, this is far from being the case. Besides writing all these papers, many of them illustrated by elaborate drawings-for Ward was an excellent draughtsman-as well as others necessarily omitted here, he produced sever books--a translation of Sachs's "Physiology of Plants, 1884; "Timber and some of its Diseases." 1889; "The Oak," 1892; an edition of Laslet's "Timber and Timber-trees," 1894; "Diseases of Plants, 1889; "Grasses," 1901; "Disease in Plants," 1901; "Trees," a considerable work, of

which several parts have appeared, and I understand that some MSS. remain to be published.

It is pleasant to reflect that so much good work was not allowed to pass unrecognised. In addition To the distinctions already mentioned, many others were conferred upon him. Ward became a Fellow of the Linnean Society in 1886, and was elected a Fellow of the Royal Society in 1888, receiving a Royal medal 1893; he served on the council of the Linnean Society, 1887-9, and on that of the Royal Society, 1895-6. He was elected an honorary fellow of Christ's College, Cambridge, in 1897, and in 1902 received the degree of D.Sc. honoris causa from his first Alma Mater, the Victoria University, having previously taken the same degree at Cambridge. He was president of the British Mycological Society, 1000-2, and had received the honorary fellowship of the Manchester Literary and Philosophical Society and of other societies.

Beginning in 1854 at Hereford, his life is a story of unremitting and successful effort until its close at Torquay on Sunday, August 26, 1906. I remember Ward as a genial companion, a man of varied interests, delighting especially in music; but the dominant impression is that of his whole-hearted devotion to his science; all else counted with him as nothing in comparison with that. No doubt this led him to impose too severe a strain upon a constitution never very robust: but such as he was, it could not have been otherwise. He was laid to rest in the Huntingdon Road Cemetery, Cambridge, on September 3, attended by many friends and colleagues, amid tokens of regret from near and far. S. H. VINES.

CHARLES BARON CLARKE, F.R.S.

THE death of Mr. Charles Baron Clarke on August 25, in his seventy-fourth year, deprives the botanical world of an able worker, and takes from a wider circle still a friend endeared for his breadth of sympathy and charm of manner.

Born at Andover in 1832, Clarke was educated at King's College School, London, and at Trinity and Queens' Colleges, Cambridge. He graduated in 1856, being bracketed third wrangler. Elected a fellow of Queens' in 1857, he was in 1858 called to the Bar at Lincoln's Inn, and appointed mathematical lecturer of his college. This position he held until 1865, when he joined the Bengal Educational Department.

While at Cambridge Clarke was one of a brilliant group holding advanced economic views, which included Henry Fawcett, Leslie Stephen, and John Rigby. His interest in political economy continued throughout his life, and found expression in occasional pamphlets on economic subjects, which he treated in a manner pleasing for its lucidity and freedom from political bias.

Before he left England, Clarke, as a recreation, was interested in field botany. On reaching India he printed at Calcutta, in 1866, a list of the plants of Andover, his birthplace. Clarke began his Indian career as a teacher in the Presidency College, Calcutta, but soon became an inspector of schools. His work as inspector involved touring within the circle allotted to him, and gave him facilities for botanical field work. Of these he made the utmost use, and supplemented them by vacation visits to districts outside his circle and provinces beyond Bengal. He made extensive collections, and at the same time found material for contributions to ethnology and geography. From 1869 until 1871 Clarke was in charge of the Royal Botanic Garden at Calcutta, with the use of a well-equipped herbarium at his command. The administrative work of these two years left little time for publication of

results, but, on reverting to his own department, Clarke, while as ardent a collector as ever, found time to commence the issue of his valuable contributions to Eastern botany. His monographs of the Indian Cyrtandracea and Commelynaceæ were issued in 1874; that of the Indian Compositæ appeared in 1876. In the former year also, Clarke, at his own risk and cost, issued a new and cheap edition of Roxburgh's "Flora Indica," which had become almost unprocurable.

The extent and value of the field work done by Clarke during the first ten years of his Indian service may be best measured by the character of the collection presented by him to Kew in 1877. This included 25,000 numbers, representing some 5000 species. The fulness of the notes, often accompanied by useful analyses; the precise indication of localities and altitudes; the excellence of the specimens themselves, combine to render this contribution one of the most munificent additions ever made to the Indian material at Kew. It represents journeys in the Bengal plain, on the Chutia Nagpur plateau, in Chittagong, in the Khasia Hills, in Sikkim from the Terai to the snows, in the Punjab Himalaya, in Kashmir and thence to the Karakoram, in the Nilgiri Hills. botanist since Griffith had seen more of India; none since Hooker had more fully examined the areas visited.

No

Early in 1879 Clarke was placed on special duty in England, and for four years was engaged at Kew assisting Sir Joseph Hooker in the preparation of the "Flora of British India "; for the second, third, and fourth volumes of this work he prepared the accounts While in of many important natural families. England Clarke also published, in 1880, a review of the "Ferns of Northe.n India." He returned to

India early in 1883, and towards the close of 1884 he was appointed to act as Director of Public Instruction, Bengal. In 1885 his services were transferred from Bengal to Assam, a change of province which admitted of his further exploration of the Surma and Brahmaputra valleys and of the Khasia and Jaintia Hills, and enabled him to make a botanical journey in the Naga Hills and Manipur, new ground even for him, the results of which were published in the Journal of the Linnean Society.

In 1887 Clarke retired from the Indian Service and settled at Kew, so as to be near the herbarium there, in which he worked for nineteen years as a volunteer. Early in his Indian career he appears to have been particularly attracted to the study of the Cyperaceæ, and one of the objects of his life was the completion of a general monograph of this difficult family, with regard to which Clarke became the recognised authority to whom botanists in every country sent their collections for identification and description. His devotion to this group, accounts of which he prepared for the "Flora of British India,' the "Flora Capensis, " and the "Flora of Tropical Africa," was not, however, exclusive, for he elaborated several important families for both the African "Floras" and for the "Flora of the Malay Peninsula," and communicated numerous botanical papers to the Linnean and Roval Societies.

Clarke joined the Linnean Society in 1867, when his active botanical work in India first began. In the society's fortunes he took the keenest interest, being, while on special duty in England and again since his retirement, one of the most trusted councillors of the society, over which he presided from 1894 until 1896. He was elected a Fellow of the Royal Society in 1882, and served on the council in 1888-9. He was also a Fellow of the Geological and of the Geographical Societies.

NOTES.

THE jubilee of the coal-tar industry will be celebrated in America next month, and Sir William Perkin, F.R.S., the discoverer of "mauve," will leave England on September 22 for New York to receive a public tribute from Americans for the services he has rendered to chemical industry and science. At a public meeting held last May, the committee submitted the following programme (1) To invite Sir (then Dr.) W. H. Perkin to be present at the American celebration as the guest of the Americans, the date of the event to be October 6 (subject to the approval of Sir William Perkin), and to consist of a banquet and symposium on the coal-tar industry; (2) the presentation to Sir William Perkin of a personal token; (3) the foundation of a Perkin medal, to be awarded annually to an American chemist for distinguished work in applied chemistry; (4) the establishment of a nucleus of a fund at the Chemists' Club in New York City for a reference and circulating library covering the entire field of theoretical and applied chemistry, which is to be in charge of a salaried librarian, and to contain duplicate sets, one of them to be used for circulation among American chemists. A sum of at least 50,000 dollars was estimated as necessary to place the library on a permanent basis. It is also expected that a substantial contribution will be made to the international fund in London. The American committee includes the names of about 150 of the leading scientific and public men in the United States.

WE notice with deep regret the announcement that Prof. Ludwig Boltzmann, professor of theoretical physics in the University of Vienna, died by his own hand at Duino a few days ago.

ON October 1 Sir George Watt, C.I.E., reporter on economic products to the Indian Government, will deliver the opening address of the session at the School of Pharmacy of the Pharmaceutical Society of Great Britain, and the president of the society will present the Pereira medal.

A REUTER message from Tiflis reports that the township of Kwareli, covering an area of five kilometres in the district of Telaff (Caucasus), has been almost entirely destroyed by an avalanche of mud, sand, and stones from the neighbouring mountain-side. Disasters of this nature are of frequent occurrence in the Caucasian valleys.

A MEETING of the German Astronomical Society opened yesterday morning at Jena, and will continue in session until Saturday. In addition to scientific business, visits will be paid to the optical works of Zeiss and to Schott's glassworks. The meeting of the German Association of Naturalists and Physicians will open at Stuttgart on September 16, so that members of the Astronomical Society who propose to attend it will be able to leave Jena in time to do so.

THE Government of Cape Colony has placed a sum upon the Supplementary Estimates toward the expenses incurred in carrying out investigations upon defects in ostrich feathers, under the direction of Prof. J. E. Duerden, of Rhodes University College, Grahamstown. A letter upon the subject appeared in NATURE of May 17 (p. 55).

THE famous engineering firm of Friedrich Krupp, Ltd., of Essen, is contemplating the erection of a technicophysical laboratory at a probable cost of 2,500,000 marks.

PROF. MAX TOEPLER, the inventor of the mercury pump bearing his name, and professor of physics at the Technical High School, Dresden, celebrated his seventieth birthday on September 7.

Prof. WILHELM HITTORF will shortly celebrate his g "Universitäts-Jubiläum " in Münster. In 1848 he was privatdocent at the then Münster Akademie; from 185extraordinary professor of physics and chemistry; and fre 1856-1875, ordinary professor of both subjects, but sincer the latter date he has only retained the professorship o physics. His professorial colleagues are presenting h with a marble bust of himself, by Herr Rüller, of Müneer Prof. Hittorf has presented 25,000 marks to the scienc faculty for the purpose of furthering scientific work.

AN international congress for the study of the Fola" regions was opened on September 7 at the Palais des Académies, Brussels, under the presidency of M. Beernaert Ministre d'État. The Times correspondent states the among those present were Dr. Nordenskjöld, M. Arctowsic. M. de Gerlache, Captain Scott, and Prince Buonaparte. Baron de Favereau, the Belgian Minister for Foreiga Affairs, welcomed the delegates. A draft scheme for the formation of an international Polar commission wa adopted on Tuesday. The primary aims of the commission are to bring about closer relations among Polar explorers, to coordinate scientific observations, and to assist Polar enterprise, without, however, organising expeditions on its own account. It was resolved to submit this scheme to the approval of the respective Governments. At the fina meeting M. Charcot announced his intention of organising a fresh expedition to the South Pole, and Dr. Nordenskjole expressed a hope that Belgians would cooperate with the French in this undertaking.

THE Committee of the Quekett Microscopical Club has arranged for a series of demonstrations at 20 Hanover Square, W., on "The Practical Use of the Microscope and its Accessories," to be given from 7 p.m. to 8 p.m. on the third Friday in each month during the ensuing session The first will be on November 16, when Mr. H. F. Angus will deal with axial substage illumination, including the use of the plane and concave mirrors, substage condensers, and methods of centring the illuminant and of obtaining critical illumination. At other demonstrations the order of which is not yet finally settled, the following subjects, among others, will be considered :-substage nonaxial illumination, including oblique and dark ground illumination; the use of the micropolariscope; various methods of illuminating opaque objects; the testing and comparison of objectives; and the employment of micre

meters and finders. These demonstrations will be in addition to the " Gossip" meetings of the club, which are held on the first Friday, and to the ordinary meetings, beid also on the third Friday of the month at 8 p.m. Further particulars may be obtained from the hon. sec., Mr. A. Earland, 31 Denmark Street, Watford, Herts.

IT is well known that during the last few years the study of protozoa has made remarkable advances. It has been shown that numerous protozoa play an important in human and animal diseases, and the unravelling of their life-histories has been attempted by many workers we enthusiasm and success. Among these workers no one