of which is 29-31 mm. This is the race cimensis of Wollaston. About the landing-place, on the east side, is another race, smaller than usual (maximum diameter 22-25 mm.), not dark, but well and conspicuously banded, and with the spire greatly depressed. It may be called race evoluta; it has possibly become distinctly segregated since Wollaston's time, since it combines the characters of the other forms, and is the sort of thing which might doubtless be obtained from them by careful breeding under artificial conditions. At the same time these races cimensis and evoluta exist to-day as pure types, very distinct and easily recognised, occupying different stations on the Ilheo de Cima.

In some ways the Ilheo de Nordeste, the most remote of the islets about Porto Santo, is even more interesting. It is a mere rock in the ocean, about 500 metres long and 300 metres high, somewhat less than 3 km. from the main island. With the aid of our boat's crew of strong Portuguese sailors, my wife and I were able to land and climb about the exces

sively rocky surface. The vegetation is scanty, but includes the beautiful stock, Matthiola maderensis, Lowe, and the orange-flowered Lotus. Ants and millipedes seemed to be entirely absent. On this lonely rock, and nowhere else, lives the beautiful snail Cryptaxis forensis, Wollaston, with dark, keeled shell and pink lip and apex. Here, and not elsewhere, is found (in great abundance) the small, button-like Discula polymorpha race gomesiana, Paiva. But here also is the invading Helix pisana and the native Plebecula punctulata, Sowerby, which abounds on the main island.

The curious little Geomitra paupercula, Lowe, abounds under rocks in dry places at Porto Santo and on the adjacent islets. It is unique in the group for its wide distribution, being found also in Madeira and all three Desertas, and in the Azores and Canaries. It sticks very tightly to the rocks or to any other convenient object. I once saw a beetle (Helops) walking along with one of these snails on its back. It is probable that at different times these snails have attached themselves to the feet of birds, and thus got carried across the sea.

The soundings taken many years ago by H.M.S. Styx (Capt. Vidal) show that Porto Santo rests on an elevated bank, indicating a former island perhaps six or seven times as large. The margins of this bank appear to be cliff-like, almost vertical, the depths suddenly increasing from, e.g., 45 to 200 fathoms. This might be taken to indicate the cliffs of the former island, perhaps dating from the Mesozoic. The oldest deposits on the island containing fossils are Miocene, and are marine. At Calheta Point one may see this Miocene material, with large shells and corals, mixed with dark volcanic rock, which seems to have been thrust up from beneath. The suggestion is obvious that the island dates only from the Miocene, but, apart from the Styx soundings, it seems improbable that the remarkable snail fauna has wholly evolved from some immigrant or immigrants since that time. The sandy fossil beds containing land shells must be considered Pleistocene. Wollaston calls these shells subfossil, but they are quite comparable with Pleistocene fossils elsewhere, and show about as much difference from the living fauna as might be expected. At the base of this series, in the Campo do Baixo, is a dense stratum of marine Pleistocene, which has been studied and will, I hope, be fully described by my friend Senhor A. C. de Noronha, a very keen and able naturalist who was born in the island.

The insect fauna of Porto Santo is scanty, but the collections obtained will doubtless prove to be of ex

ceptional interest when studied. Three species of butterflies are common, Colias edusa, Vanessa cardui, and V. callirhoë, the last breeding abundantly on the nettle Urtica membranacea, Poir. Wollaston considered that specimens of the Porto Santo V. callirhoë were smaller than those of Madeira, but I could not see any difference. We found only two species of of bees, both Andrena. Νο fossorial wasps could be found, though the sandy country seemed exactly suited to them. The numerous spiders appear to have no Pompilidæ to attack them. At the back of the town rises the tall Pico do Castello, and on its summit may be seen a building in which the inhabitants used to take refuge from the Moorish pirates. A cannon remains on the side of the mountain, half-buried in the earth. To-day the lowlands of Porto Santo are overrun, like those of Madeira, by the obnoxious little ant Iridomyrmex humilis, which has exterminated the once-abundant house-ant, Pheidole megacephala. But on the top of the Pico do Castello we found the Pheidole still holding out, with numerous strong nests.

The flora is scanty, and was not specially studied by us. We were interested to find the orchid Gennaria diphylla, Lk., on the Pico do Castello and Pico d'Anna Ferreira. The Pico do Castello has been extensively planted with trees in recent years, and I thought the orchid might have been introduced with soil, but this seems unlikely in the case of the Pico d'Anna Ferreira, which remains in its original condition.

The people of Porto Santo are a hardy and industrious race who win a scanty living from the sea and soil. We found them exceedingly friendly and cheerful, and left them with strong feelings of regard. We were specially indebted to our guide, Senhor Juan do Pico, who knew every path and byway. T. D. A. Cockerell. Hotel Bella Vista, Funchal, Madeira, February 3.

The Energy of Cyclones.

IN the recent discussion in NATURE on the energy of cyclones no mention has been made of tropical cyclones, although these are the most remarkable phenomena of their kind.

The

It is impossible to apply to these cyclones the theories which ascribe the energy of the rotating wind system to the re-adjustment of equilibrium of warm and cold masses of air within that system, since in the cyclones of the tropical zone temperature and humidity are symmetrically distributed. In these cyclones warm and cold sectors do not exist. Indian meteorologists Henry Blanford, Sir John Eliot, Fr. Chambers, and W. T. Willson have published papers on the cyclones of the Bay of Bengal and the Arabian Sea, giving a full explanation of their origin and development. These very important works no longer receive the attention they deserve. They also throw much light upon the source of energy in these cyclones. I endeavoured to make a rough calculation of the energy contained within one of these whirls, taking into account the preceding pressure distribution over the hurricane region, and the results were in good agreement with the observed wind forces. I should therefore like to direct attention to this work. The calculation was based upon observations of the Backergange cyclone. It is given in my "Lehrbuch der Meteorologie" (1901 edition, p. 579, footnote), as well as in a paper, 64 'Remarks on the Origin of (Tropical) Cyclones (Meteorologische Zeitschrift, 1877, August, p. 311). My calculation has no ap

plication to the cyclones of middle and higher latitudes, as it presupposes simple whirls like the symmetrical cyclone of the tropics. J. VON HANN. Vienna, February.

The Ascent of Mount Everest.

THE opportunity which mountaineers and geographers have long looked for of approaching Mount Everest from the north has at last arrived. The Tibetan Government has given its consent for the dispatch of an expedition to explore the mountain. The expedition is now being organised by a combined committee of the Royal Geographical Society and the Alpine Club, and an attempt will be made to ascend this the highest mountain in the world.

The cost of the expedition is estimated at about 10,000l. Already a quarter of this amount has been raised among the members of the two societies. But the expedition will have to leave England very shortly, and it is essential to its success that the equipment shall be the best possible, and that no financial uncertainty shall delay the organisation in India of a picked corps of Himalayan porters and of an adequate transport service. Heavy initial outlay is therefore involved, and we now appeal to the general public, confident that it will wish to further an enterprise the successful accomplishment of which will bring so much credit to this country.

Subscriptions should be sent to the Treasurer, Royal Geographical Society, Kensington Gore, S.W.7, or to the Bank of Liverpool and Martins (Cocks, Biddulph, and Co.'s branch), 43 Charing Cross, S.W.1. FRANCIS YOUNGHUSBAND, President, Royal Geographical Society. J. N. COLLIE,

President, Alpine Club.

February 23.

Pure Organic Chemicals.

I AM glad to see that the writer of the leading article in NATURE of February 24 directs attention to the concern with which research workers view the possibility of foreign organic chemicals being restricted or excluded by legislation in the interests of British manufacturers.

The latter are not yet in a position to supply many materials in that state of unquestioned purity such as one associates with the old firms of Merck and Kahlbaum in Germany and Poulenc Frères in France. As an illustration I may mention that I recently ordered a pound of propyl alcohol (as catalogued) from a British firm, and at the same time a like quantity from Poulenc Frères. The first forwarded a material costing 18. which consisted of a mixture boiling over a wide range of temperature but containing no propyl alcohol, whereas the French firm supplied a pure sample of nearly constant boiling point costing IIS., including postage. J. B. COHEN.

The University, Leeds, February 25.

Nature of Vowel Sounds.

WITH regard to the very interesting researches on vowel sounds by Prof. Scripture published in NATURE of January 13 (p. 632) and January 20 (p. 664), I beg to be permitted to state that the attempt of Helmholtz to produce vowels with smooth, simple tones has since been fully confirmed. Using, instead of tuningforks, bottles caused to sound by currents of air blown over their orifices, which, as is well known, give almost perfectly simple tones, I have been able to demonstrate this myself. The remarkable and

extended investigations of Prof. Miller described in his book, "Science of Musical Sound," have fully proved the statement of Helmholtz to be true, as have also the researches of Prof. Stumpff, of Berlin. I am therefore of the opinion that the Helmholtz theory of vowel sounds can scarcely be doubted any longer. Her. mann's and Scripture's method of producing vowels by sending puffs of air through a resonator does not contradict this. Whenever a complex vibration is set up which appears to be a mixture of simple tones corresponding to the sound of a vowel, there will be produced a vowel. However, it is very important to have repeated Hermann's experiments and extended them by using resonators with soft walls. CHARLES DE WESENDONK.

Hôtel Eden, Montreux, Switzerland.

THE above letter very properly directs attention to the excellent work of Prof. Miller. It is worth while to study Fig. 130 of his book, reproduced below. For the tuning-fork there is only one tone, namely, the fundamental. For the other instruments the fundamental appears clearly, but for the voice the fundamental is lacking. Thus the strongest tone in a vowel, the voice tone, does not appear in the plot. This is in agreement with the work of Hermann and myself. As explained in NATURE of January 13 and 20, this arises from the fact that the voice tone consists of a series of puffs.

together such scattered information as exists concerning the early history of science in that University, and to commemorate the achievements of Tunstal, Richard of Wallingford, Merle, Mauduit, Rede, Aschenden-forgotten worthies of a medieval time and of Digges, Recorde, Dwight, Lower, Mayow, and others of a later period. As regards physical science, it is intended to illustrate its development by a sort of catalogue raisonné of scientific instruments, mainly from the collections in the various colleges and University departments which are known to be rich in specimens of the best work of the craftsmen of the seventeenth and eighteenth centuries.

The present booklet-the first instalment of the projected series-deals with the history of chemistry at Oxford down to the time of Daubeny. It traces the beginnings from Roger Bacon (1214-92), who may be said to have well and truly laid its foundations as a science by his insistence on the appeal to experiment. His dictum, Sine experientia nihil sufficienter sciri potest, now over the entrance to an Oxford laboratory, is significant not only of his breach with scholasticism, but also of his clear recognition of the path that science must follow. Mr. Gunther deals only in very general terms with the influence of Bacon-more with his teaching and the essential nature of his philosophy than with his actual achievements. He sees his limitations in the dominance of the Greek philosophy, and in his inability to act, through force of circumstances, upon his own principles. Considering that Bacon's name is associated with Oxford traditions, and that the book is primarily intended for Oxford students, to whom, indeed, it is dedicated, more space might well have been allotted to one who was at once the earliest and among the greatest of our [Oxford] teachers."

The early association of chemistry with medicine was, of course, felt in Oxford, as elsewhere. The Spiceria of medieval Oxford were to be found in the High Street, near the site of the present front of Brasenose College. Their shops, which did not escape being occasionally "ragged," dealt originally in spices, seeds, and roots, and only gradually developed into apothecaries. One of the earliest was that of John le Spicer, whose shop, in 1332, was in All Saints parish. Gunther furnishes a plan showing the apothe- | caries' quarters in Oxford, and he gives illustrations of their receptacles for drugs from the series in the Ashmolean Museum.

Mr.

From the times of Roger Bacon and the early spicers to the middle of the seventeenth century is a big jump. But Oxford contributed nothing to chemical science during the intervening period. The study of natural phenomena was foreign to the scholastic learning of the time. As Mr. Gunther points out, "the long list of Waynflete

1 "Early Science in Oxford." Part i., "Chemistry." By R. T. Gunther. Pp. vi+91. (Oxford: The Oxford Science Laboratories, 1920.) 65.

any original work, shows how barren discourses on this subject must be, when they are founded on Aristotle rather than on Nature." There were, however, alchemists during this period in Oxford, among them the Rosicrucian Fludd, of St. John's, in 1591, and Simon Forman and John Thornborough (1602), of Magdalen. Mention should also be made of John French (1616–57), who wrote treatises on distillation, "partly taken out of the most select Chymicall Authors of several Languages, and partly out of the Author's manuall experience." But the real awakening in Oxford occurred during the troubles of the Civil War, when Wilkins, Ward, Bathurst, Petty, and Willis met weekly, first in an apothecary's house for "the convenience of inspecting drugs," next at the lodgings of Dr. Wilkins, warden of Wadham, and afterwards at the lodgings of Mr. Robert Boyle. The last-named had settled, in 1654, in Crosse's rooms in the High Street, having recently left Ireland, "a barbarous country," he says, "where chemical spirits were so misunderstood, and chemical instruments so unprocurable, that it was hard to have any Hermetic thoughts in it."

This association of the progenitors of the Royal Society with Oxford is an incident of which the University is justly proud, and Mr. Gunther treats of it in some detail. Boyle, who was of a tender constitution, was devotedly looked after by his sister, Lady Ranelagh, who came up to Oxford to settle him in his lodgings. While there, we learn from a letter which Mr. Gunther prints, she was not wholly satisfied, as she thinks the position of the doors with respect to the fireplace, even in the warmest room, will occasion draughts, "the inconvenience" of which "may be helped ... by a folding screen. Boyle, however, was sufficiently comfortable to remain there for fourteen years, when he removed to London to his new laboratory at the back of Lady Ranelagh's house in Pall Mall. Crosse's house in Oxford was pulled down in 1809; it was where the Shelley memorial now stands. Mr. Gunther gives a re production of an old print showing it and its relation to University College and other buildings in the High Street (Fig. 1).

Oxford owes to Boyle its first regular teacher of practical chemistry-Peter Sthael, of Strassburg, "a Lutheran, a great hater of women, and a very useful man,' ," who had been engaged by Boyle as one of his assistants. He began his courses in 1659. Among his pupils was John Locke, of Christ Church, "a man of turbulent spirit, clamorous and never contented. The club [class] wrote and took notes from the mouth of their master, who sat at the upper end of a table; but the said J. Lock scorned to do it; so that while every man besides of the club were writing, he would be prating and troublesome." That the fingers of the troublesome J. Locke did actually itch to be at chemical experimenting is shown by

The early memoirs of the Manchester Philosophical Society contain several papers by Wall, brief notes of whose lectures are preserved in MS. in the Radcliffe library and in private letters of the time; some of the latter are printed by Mr. Gunther. Wall is described as a "learned, ingenious, and pleasing gentleman," who once had the honour of drinking tea with Dr. Samuel Johnson. A contemporary of Wall's, James Higginbotham, of Magdalen Hall, afterwards James Price, of Guildford, was the last of the English alchemists, and killed himself after the exposure, by a committee of the Royal Society, of his pretensions to transmute mercury into gold.

From the closing years of the eighteenth century to the time of the foundation of the Aldrichian professorship, Oxford readerships in chemistry were held in succession by Dr. Thomas Beddoes (1788-93), best known as the founder of the "Pneumatic Institution" at Clifton, and the discoverer of Humphry Davy; and Dr. Robert Bourne, a fellow of Worcester, and an eminent medical man of his time. Indeed, practically all the readerships were held by medical men, and their teaching was largely directed to the needs of medicine.

In 1803 Dr. G. Aldrich endowed a professorship of chemistry. The first occupant of the chair was John Kidd, who held it from 1803 to 1822. He is the author of two papers in the Phil. Trans., one on "Naphthaline, a peculiar substance produced during the decomposition of coal-tar"; the other on "The natural production of Saltpetre in the walls of subterraneous buildings," the saltpetre having been scraped from "the hoary walls" of the basement of the Ashmolean Museum in which Dr. Kidd and his family resided.

Pons-Winnecke's Comet

By W. F.

A NEW comet was discovered by Jean Louis

Pons at Marseilles in June, 1819, and it was observed during five weeks. From the observations obtained, Encke computed that the comet was revolving in an elliptical orbit, with a period of 2052 days, or 5.618 years. Nothing more was, however, seen of the object until nearly forty years afterwards, when Winnecke re-discovered it, and also re-determined its period of revolution. It has since been observed in 1869, 1875, 1886, 1892, 1898, 1909, and 1915. During the last fifty years the planet Jupiter has somewhat disturbed the orbit of the comet, for the two objects made several near approaches. Two periods of the comet are nearly equivalent to one period of Jupiter, hence at alternate visits of the former to aphelion, as in about 1872, 1883, 1895, and 1907, the perturbations were considerable. These had the effect of lengthening the comet's period and bringing that section of its course which is nearest to the sun almost into conjunction with the earth's path at the end of June.

On June 28, 1916, a meteoric shower of strik

Dr. Kidd was succeeded by Dr. Charles G. B. Daubeny, a professor of botany to chemists, and a professor of chemistry to botanists, who held the chair for thirty-two years, when his "increasing duties at the Botanic Garden compelled him to resign his Chemical Professorship." The cellar at the Ashmolean, although, as Daubeny said, "notoriously unworthy of a great University, being dark, inconvenient, and confined," was afterwards occupied by the late Prof. Story-Maskelyne, who gave instruction there in chemical analysis. An incident connected with his tenancy of this basement is related by Mr. Gunther in a footnote with which this notice of a most interesting account of Oxford's relations to chemistry must conclude :

Some workmen were employed to make some alterations to a wall when one of them drove his pick through into a small room that had evidently not seen the light of day for generations. They enlarged the aperture, and, on entering, found some bottles that appeared to them of extreme antiquity. Very naturally they tasted the contents and speculated on the possible origin of the long forgotten hoard. When eventually the discovery was reported to Maskelyne, then at the mineralogical department at the British Museum, he exclaimed, "They have broken into my cellar, the stupid idiots. If they had only looked at the other side they would have seen my new oak door." But what probably rankled in his mind was the thought that his own gin had impaired their clear vision.

Mr. Gunther's surmise cannot, however, be well founded, as the gin was reached only after the wall had been broken through. It was presumably the same wine cellar that Dr. Daubeny had vainly petitioned Convocation to improve for him.

and its Meteor Shower. Denning.

ing and abundant character was observed by the present writer at Bristol. It was first seen there at 10.25 p.m., and half an hour later it was also observed from Bournemouth and Birmingham. The sky was not very favourable, but at Bristol sixty-nine meteors were observed in about two hours, including twenty of the first magnitude, and the radiant point appeared to be diffused over the region of n Ursa Majoris, Boötis, and a little east. This position position corresponded approximately with the radiant point computed for Pons-Winnecke's comet, and the date was also correct, so that an intimate association (or identity) of the two phenomena was suggested (see Monthly Notices of the Royal Astronomical Society for 1916, vol. lxxvi., p. 742). The meteoric shower named is likely to be repeated, and on a more brilliant and abundant scale, on about June 27 next, for the comet will be very much nearer to the earth than it was in June, 1916. On that occasion the meteors were seen about ten months after the comet's nucleus had passed through perihelion, so that the stream of