ratus on the principle of the wave-siren. Its mode of operation will be best understood by reference to Fig. 5 taken by Dr. Koenig's permission from his work, Quelques Expériences d'Acoustique." Upon a strong stage about 4 feet high is mounted a series of 16 brass disks, cut at their edges into sinusoidal wave-forms, all fixed upon a common axis, and capable of being rotated by a band and treadle. The wave-forms cut against the contours of these 16 disks represent a harmonic series of 16 members of decreasing amplitude, there being just 16 times as many sinuosities on the largest as on the smallest disk Against the edge of each of these wave-disks wind can be blown by a special mouth-piece in the form of a horizontally-placed slit connected by a tube to a powerful wind-chest mounted upon the stand of the instrument. We have, in fact, here sixteen simple wave-sirens of different pitch all combined together in such a manner that any one of them can be used separately. When the axis is rotated the wave-disks pass in front of the slits through which the wind is blown, and throw the issuing streams of air into vibration. Each wave-disk thus sets up a perfectly simple tone. We have therefore provided in this instrument a fundamental sound with its fifteen upper partial tones. It is clear that any desired combination

can be made by opening the appropriate stops on the wind chest. In order to vary at will the phase in which these elementary tones are combined, a very ingenious arrangement is adopted. The brass tubes which terminate in the fifteen mouth-pieces are connected by flexible caoutchouc pipes to the wind-chest. The mouthpiece tubes are mounted upon a plate in such a way that they can slide up and down in curved slots concentric with the disks. By the aid of templates cut out in combfashion, and screwed to a lever handle, the mouth-pieces, or any set of them, can be displaced at will; thereby introducing any required difference of phase. Fig. 6 shows the way in which the fifteen mouth-piece slits are arranged with respect to the wave-disks; there being two series along two different radii, eight corresponding to the even members of the series, and seven to the odd members. They are set with the slits each opposite a summit or crest of its wave-disk, so that all the slots are closed simultaneously. This in Koenig's nomenclature corresponds to a phase of; the minimum condensations of all the individual air-waves occurring simultaneously. Suppose now it is desired to change the phase in which the waves are compounded, and to make all the maximnm condensations occur simultaneously (i.e. d): all that

If first we take simply the fundamental and its octave together, the total resultant sound has the greatest intensity for d , and at the same time the whole character of the sound becomes somewhat more grave, as if the fundamental tone predominated more. The intensity is least when d = 3. If, however, attention is concentrated on the octave-note while the phase is changed, the intensity of it appears to be about the same for d = and , but weaker in all other positions.

d

=

o and, but the quality for is always the same as that for, and the quality for o is always the same as for This peculiary corresponds precisely to the peculiarity of the curves (see Fig. 4, b and d), in which the resultant wave-forms are correspondingly identical.

For compound tones corresponding to the whole series, odd and even, there is, in every case, minimum intensity, brilliancy, and stridence with d= 3, and maximum when d = ; the phases o and being intermediate. A reference to Fig. 4, a and b, will here show that the maxima of

on

AT the stance of the Paris Academy of Science that a gathering of savants, friends, and admirers of M. Pasteur having resolved to present him with a medal commemorative of his remarkable discoveries, a committee had been appointed to watch the execution of it. On completion of the work, this committee, on June 25, repaired to M. Pasteur's house to present the medal, which is the design of M. Alphée Dubois, and happily recalls the physiognomy of its distinguished recipient. The meeting included MM. Dumas, Boussingault, Bouley, Jamin, Bertin, Tisserand, Davaine, and others. On this occasion M. Dumas delivered an address, in which he recalled the labours of M. Pasteur; and after receiving the medal, M. Pasteur made a few observations in reply. The two speeches have been, on the suggestion of M. Thenard, inserted in Comptes rendus, and we here reproduce them, in translation. M. Dumas said :

"MY DEAR PASTEUR,-Forty years ago you entered this house as a student. From the first your teachers foresaw that you would be an honour to them; but none would have ventured to predict what brilliant services you were destined to render to science, to the country, and to the world.

66

Your earliest labours banished occult forces for ever from the domain of chemistry, by explaining the anoma

lies of tartaric acid.

"Confirming the vital doctrine of alcoholic fermentation, you extended this doctrine of French chemistry to the most diverse fermentations, and you gave to the manu

FIG. 10.-Effect of inclining the slit.

surely win a place amongst the familiar experiments of

acoustics.

S. P. T.

facture of vinegar, rules which industry now applies with thankfulness. these infinitely minute living dis

66

covered a third kingdote, to which those beings belong which, with all the prerogatives of animal life, do not need air to live, and which find the heat they require in the chemical decompositions they excite around themselves.

"The profound study of ferments gave you the complete explanation of alterations undergone by organic substances-wine, beer, fruits, animal matters of all kinds; you explained the preservative role of heat applied to their conservation, and you learned to regulate the effects of it according to the temperature necessary to cause the death of ferments. Ferments when dead produce ferments no more.

"It was thus that you were led to maintain throughout the extent of the organic kingdoms the fundamental principle according to which life is derived from life, and which rejects as a useless and unfounded supposition the doctrine of spontaneous generation.

"It is thus that, showing air to be the vehicle of the germs of most ferments, you learned to preserve without alteration the most putrescible matters, by keeping them from all contact with impure air.

"Applying this idea to the alterations, so often fatal, to which wounds and sores are liable when the patients inhabit a contaminated place, you learned to guard them from this danger by surrounding their limbs with filtered air, and your precepts, adopted by surgical practice, daily insure to it successes it knew not before, and give its operations a boldness of which our predecessors had no presentiment.

"Vaccination was a beneficent practice. You have discovered its theory and enlarged its applications. You have learned how to produce vaccine matter from a virus; how a fatal poison becomes a harmless preservative. Your researches on anthracoid disease, and the practical consequences from them, have rendered to agriculture a service of which all Europe feels the value. But the results already obtained, however brilliant, are nothing in comparison with the applications which may be anticipated from the doctrine to which they are due. You have furnished a sure basis to the doctrine of viruses by associating it with the theory of ferments; you have opened a new era for medicine by proving that every virus may have its vaccine-matter.

'Amid these admirable conquests of pure science, natural philosophy, and practice, we might forget that there is one part of the country where your name is pronounced with particular respect-the country once so fortunate, where the silkworm is cultivated. A malady which had spread terror among all the families of our southern mountains had destroyed the fine races they had produced with much care and wise selection. The ruin was complete. Now, thanks to your processes of scientific grainage, the cultivators have regained their security, and the country sees one of its sources of wealth reviving.

"My dear Pasteur, your life has only known successes. The scientific method, of which you make such certain use, owes you it's finest triumphs. The Normal School is proud to count you among the number of its students; the Academy of Sciences is elated at your researches; France ranks you among her glories.

"At a time when, from all parts, testimonies of the public gratitude are arising towards you, the homage we come to offer you in name of your admirers and your friends, may seem to you worthy of special attention. It emanates from a spontaneous and universal sentiment, and it preserves for posterity the faithful image of your features.

"May you, my dear Pasteur, long enjoy your honour, and contemplate the fruits, ever richer and more numerous, of your labours. Science, agriculture, industry, humanity, will feel eternal gratitude to you, and your name will live in their annals among the most illustrious and the most venerated."

M. Pasteur replied as follows:

“MY DEAR TEACHER, -It is forty years, indeed, since I had the good fortune to make your acquaintance, and since you taught me to love science and honour.

"I came from the provinces; after each of your lectures, I went out from the Sorbonne, transported, and often moved even to tears. From that time, your talent as professor, your immortal works, your noble character, have inspired me with an admiration which has only increased with the maturity of my mind.

"You must have divined my sentiments, my dear Teacher. There is not a single important circumstance of my life or of that of my family, circumstance happy or painful, which has found you absent, and which you have not, in some sort, blessed.

And here you are still among the foremost in expression of these testimonies, excessive truly in my opinion, of the esteem of my teachers, who have become my friends.

"And what you have done for me you have done for all your students. It is one of the distinctive traits of your nature. Behind individuals you have always contemplated France and her greatness.

What shall I do henceforth? Hitherto great eulogia had inflamed my ardour, and only inspired the idea of rendering myself worthy of them by new efforts; but those which you have addressed to me, in name of the Academy and of learned societies, truly overpower me."

NOTES

THE Council of the Society of Arts have elected C. W. Siemens, D.C.L., LL.D., F.R.S., as Chairman for the ensuing

year.

IT has now been definitely decided to build a permanent observatory on Ben Nevis.

It is announced that the Duke of Bedford has given 5000, College, Oxford. for the endowment of a lectureship in physical science at Balliol

DR. GEORGE DICKIE, ex-Professor of Botany in the University of Aberdeen, died at Aberdeen on Saturday morning. The deceased, who was a native of Aberdeen, and was educated at Marischal College, was for some time in practice in the city as a doctor and dispensing chemist. His tastes, however, lay very markedly in the line of botanical research. He held the Botanical Chair in the Queen's College, Belfast, for a number of years, and on the fusion of King's College and Marischal College into one Aberdeen University he was appointed Professor of Botany. He discharged the duties for seventeen years, only resigning in 1877 on account of impaired health. Dr. Dickie had written numerous papers, and published some books connected with his favourite study, these including "A Handbook of Flora of Aberdeenshire," which was subsequently supplemented by a much larger volume, "The Botanist's Guide," published in 1860. His favourite department of botanical study was Alge. On the return of the Challenger expedition he was, for the purposes of study, supplied with the Alga collected during the cruise.

LET us draw the attention of local natural history societies to the prospectus of the forthcoming International Fisheries Exhibition. On some points these societies might be able to render material aid to the Commissioners, who, we believe, are desirous of enlisting their co-operation. Indeed, all of our readers interested in such an exhibition should procure copies of the prospectus by applying to the Secretary, 24, Haymarket, London, S. W. The Exhibition will cover a very wide field, and therefore appeals to a great variety of interests.

PROF. A. SMITH of the Swedish National Museum, who has been delegated as the representative of Sweden at the Fishery Exhibition in London next year, has commissioned Dr. A. Malm to prepare a collection of the sea fish species of the west coast of Sweden, to be forwarded at the expense of the museum. Dr. Malm will also arrange the collection which the Gothenburg Museum will exhibit, Mr. O. Dickson having offered to defray the expenses thereof. Mr. Dickson has been chosen as the "honorary correspondent" of Sweden at the exhibition.

THE Sydney Morning Herald justly animadverts in strong terms on the geography in some of the school books in common use in New South Wales, under the sanction of the government. These are published by a well-known Glasgow firm, and no attempt has been made to adapt them either to the conditions of the Southern Hemisphere, or to recent knowledge. The Herald gives some choice examples of the "facts" taught to the rising generation at the Antipodes. "At twelve o'clock," the book tells us, "in the day, when you go out to play, if you look at the part of the sky where the sun is shining, that part is called the south; then turn and look behind you, where the sun never comes, that is the north, it is opposite the south." Again, 'the country you live in is Ireland; it is called an island because it has water all round it, and is not joined to any other country;" the Herald states, "and this has been taught to Australian children, at the expense of the public of New South Wales, for the last thirty or forty years." In a chapter headed "Australasia," there is the following passage:-"The name of Austral

asia or Southern Asia is given to a number of islands in the Indian and Southern Oceans. The largest of these is New Holland, which is nearly as extensive as the whole of Europe. Much of the greater part of New Holland is unknown to Europeans; but there are British settlements on the coast. It is inhabited by a race of savages who are among the lowest and most degraded that are to be found in the world." The moral seems to us to be that the Australians ought to compile their own school-books.

THE invertebrate portion of the collection of fossils made by the late Mr. Charles Moore, now in the Royal Literary and Scientific Institution of that city, is being classified and arranged by Messrs. R. Etheridge, jun., and R. Bullen Newton, of the British Museum. The vertebrates will afterwards be examined by Mr. Wm. Davies of the British Museum.

OUR contemporary, L'Electricité, in an able article on the progress of electrical science, remarks that in all the most striking of recent advances it is improvement rather than invention that comes to the front, and that no compromise or equivocation can deny justice to the real original discoverers. "Bell does not efface Reis in spite of the recent Chancery suit; Faure cannot destroy Planté; and Swan, Edison, and the others cannot suppress the anterior labours of Changy."

It is proposed to establish a “German Botanical Society" for the whole of the "Vaterland," founded on, and an extension of, the already existing "Botanical Society for the Province of Brandenburg." A conference for the purpose of founding the new society is summoned to meet at Eisenach on September 16; the conveners including many of the most distinguished botanists from all parts of Germany.

THE most recent issue of the "Bulletin de la Fédération des Sociétés d'Horticulture de Belgique," published under the authority of the Belgian Minister of the Interior, contains the usual evidence of the activity of horticulture in that little kingdom, as well as the ninth annual issue of Prof. Morren's valuable "Correspondance Botanique."

AT the sixth anniversary meeting of the Sanitary Institute, Mr. E. C. Robins read a paper on the work of the Institute. After dealing with the objects of the institution, which are to awaken the conscience of the country generally to the importance of preventive measures in arresting the spread of disease, to acquire and impart information upon all matters connected with the public health, and to influence the laws which might be framed for the public good in connection with sanitary matters, the reader addressed himself to these things, which still remained to be performed. With respect to the examination conducted by the Institute, it might soon be necessary to consider the extent to which technical education should be required as a condition precedent to such examination if the standard of efficiency for the offices of local surveyors or inspector of public nuisance was to be permanently raised. He was happy to think that during the last six years science classes were being established throughout the country by the municipal authorities of various cities. Instances were then given by Mr. Robins of the disabilities under which sanitarians laboured. The influence of the institute might be also used in favour of the public, and especially of the humbler portion of it, by getting a revision of the Water Companies' Act, which had granted to them inquisitorial powers quite inconsistent with public purposes of a sanitary nature. Another and pressing want of the day was greater uniformity in the bye-laws governing the action of local authorities.

A MEMORIAL has been presented by the Council of the Society of Arts to the Secretary of State for India calling attention to the great and growing demand for the services of persons skilled

in forest cultivation and analogous occupations, in India and the Colonies generally, and to the increasing desire on the part of land agents, land stewards, and bailiffs to acquaint themselves with the scientific and technical treatment of plantations, woods, and forests, as a means of fitting them for the more satisfactory management of landed estates in the United Kingdom. The memorialists believe that no suitable provision exists at any of our great centres of instruction in this country for the teaching of natural science in its special reference to forestry, nor for the scientific teaching of sylviculture in any of its branches; and are of opinion by grafting itinerating classes for observation of the practical method adopted in the regularly worked forests abroad on classes for scientific teaching at home, established in connection with such a school as already exists at Cooper's Hill, satis factory means could be afforded of enabling students to obtain the requisite knowledge, both theoretical and practical, to qualify them for entering upon the duties appertaining to forest manage ment, whether in India, our colonies, or elsewhere. They therefore express their earnest hope that steps may be taken by the Council to establish a department for the teaching of forestry in the Royal Engineering College at Cooper's Hill.

WE have received a "Catechism" of modern elementary chemistry, or solutions of questions set at examinations of the London University, for the last twenty years, by the Lecturer on Chemistry at Downside. The appearance of a book like this is a further indication of what we are drifting to in this country in regard to science teaching. The numerous examinations have created a method of study which will meet the examination with the least expenditure of labour on the part of the student, Numerous small books on different branches of science have appeared with this object, containing a mass of facts simply crammed into them, and hence have earned the very appropriate term "cram books." They serve to "get up the Exam.,” and are of no further use, generally creating a dislike of the subject. The little book before us is scarcely one of these, but it is an examination helper more in the manner than the substance. It contains over 400 questions that have been actually set, with answers appended, and will undoubtedly be useful in preparing for the matriculation and other examinations. It is intended to be used as an aid to a text-book, and as such is to be commended.

M. DELAPORTE, who has been exploring the celebrated remains of Cambodia on behalf of the French Government,

propounds the idea-novel, we believe-that the remains at Angkor and elsewhere are due neither to Buddhism nor Serpent. worship, but were born of Brahminism. He finds figures and emblems of Siva, Vishnu, Rama, and other Brahminic gods and heroes everywhere. M. Delaporte has brought home numerous photographs, mouldings, &c., and the details of his discoveries, on which his new theory is based, will be anxiously looked for by archaeologists. A brief note on the subject will be found in the Bulletin of the Society for Encouraging National Industry (May).

CONSIDERABLE consternation has been caused by the appear. ance of the Phylloxera at several points in the Canton of Neuchatel and Geneva.

In order to secure the greater purity in the atmosphere of the St. Gothard Tunnel, an attempt is to be made to propel the locomotives by electricity. Experiments, for which the sum of 180,000 francs is set apart, are now being made at Berne with this object.

An earthquake shock lasting four seconds was felt on Monday morning at half-past four o'clock at Laibach and Trieste Another shock, lasting longer, was felt at nine o'clock. A smart earthquake shock, accompanied by subterranean thunder, was