The Diamond.The recent discovery of a new locality for the Diamond has to some extent increased the interest which has always been felt in that which is considered the highest and purest of gems, and the most beautiful among the productions of nature, although sometimes cqualled, if not surpassed, by its allies, the sapphire and ruby.

The diamond is the hardest substance known, hence the Greek name adamas was said to be applied to this stone; it is, however, very brittle. In the rough state it is usually devoid of brilliancy, and is only semi-transparent, having some resemblance to gum-arabic. It crystallises in the various forms of the cubical system, and occurs chiefly in octohedral, tetrahedral, and dodecahedral forms. It cleaves with facility at planes parallel to those of the cctohedron, and this property is always taken advantage of in the cutting, as well as in the removal of flaws and imperfections in the stone.

A well-cut diamond is remarkable for its brilliancy and play of colour, properties connected with the great refractive power of the stone. It is the object of the lapidary so to arrange the facets above and below, that they may reflect the refracted rays of light in different directions, instead of allowing them to pass through the cut stone. The diamond is usually cut into one of three forms, partly, but not entirely, dependent on the original form, size, and perfection of the stone; these are termed the brilliant, rose, and table. The former is considered to be the most favourable shape for developing all its beauty. To these forms may be added the lasques, cut in India from flat and veiny stones. Lapidaries assert that the more nearly the rough form of the diamond is that of the octohedron, the less loss will there be in cutting it, and the better will it be in many other respects.

The hardness of the diamond is 10 in the scale of minerals, and the specific gravity is 35; besides being colourless, it occurs of varicus colcurs-green, blue, brown, yellow, pink, orange, and black. Sometimes the diamond has been mistaken for the topaz, and also for sapphire when blue; but the topaz and rock crystal (in the forms known as Bristol, Irish, and Welsh diamonds) have been more frequently mistaken for it. It is readily distinguished from these two minerals by the following characters :

Hence the diamond differs in its crystalline form, cleavage, and hardness from topaz and rock crystal, and from the latter again in specific gravity. It is thus distinguished also from faste, which is sometimes made to imitate it, but which is much softer. The diamond consists of pure carbon, and though it is infusible, it may be burned into carbonic acid gas, by directing with a lens the sun's rays upon it when suspended in a jar of oxygen gas-an experiment originally made by the chemist Lavoisier. It becomes positively electric by friction, and has the power of emitting light when carried into a dark chamber, after having been exposed for some time to the light of the sun or the electric light. Its high refractive power led Newton to infer it was combustible, and this conclusion was verified in the same year, 1693, by the Florentine Academy. Its chemical nature has suggested the notion that it may have originated from the slow decomposition or change of vegetable or organic matter, by which the other combined elements have been eliminated; and its near relation to plumbago and anthracite, other natural forms of carbon, may have strengthened the supposition.

(To be continued)

ON THE ACOUSTICS OF THE ORCHESTRA,

BY DR. W. H. STONE, M.A., F. R. C. P.

[Two Lectures delivered November 10 and 17, 1870.]

THE
HE Second Lecture* was devoted to the consideration of the principal
Orchestral Wind-instruments.

They were divided into Flutes, Reed instruments, and Brass instruments with cupped mouth-pieces.

The first of these, like the diapason pipe of an organ, originate musical vibrations in the contained column of air by forcing it against a sharp edge of the lateral orifice, and thus, as it were, splitting it into two currents.

The second class possess what, from its most usual material, is termed a Reed. This in the clarinet, and other single-reed instruments, is a flat plate cut from the outer surface of a tall grass which grows in the south of Europe, thinned to a feather-edge at one extremity, and standing about the thirtieth of an inch from the curved table of the mouth-piece. In the oboe and bassoon two such thin plates are laid side by side, leaving a small fissure between them. These vibrating laminæ, gently pressed between the lips and excited by the breath, produce the characteristic tone of the instrument. In the harmonium and organ a brass lamina, or even one of steel, replace the cane; and in the former, the reed being free to pass the edges of the rectangular orifice in which it is set, is termed a free reed, in opposition to the beating reed of the organ and clarinet. The latter, if unskilfully set or used, may, and occasionally do, strike and jar against the edge of the mouth-piece, producing the unpleasant sound known to musicians as a goose.'

دو

Brass instruments with cupped mouth-pieces all consist essentially of a long conical convoluted tube, terminating below in an expanded bell, and above in a small metal cup, with rounded edges, against which the tense lips of the performer are firmly pressed in playing. A gentle stream of air directed through the elastic fissure thus formed, produces a series of harmonic sounds, which are further modified by valves, slides, keys, or by the insertion of the hand into the bell of the instrument. The position of the lips thus very closely resembles that of the vocal chords, or rather membranes, as they should be termed, in the human larynx.

It is obvious that there are two elements in the production of sound from a wind instrument: first the pressure of wind in the lungs; and, second, the tension of the lips. This the Lecturer had investigated some years back with a more strictly physiological object, and he reproduced the experiments on a large scale. He showed that the muscular power of the pectoral and thoraic muscles, including specially the diaphragm, far exceeded the resistance of the lip; consequently the latter might be taken as a measure or limit of the utmost force ever thrown on the lungs in playing. In his own case a column of water could be raised to a height of about six feet, before the lip gave way. He then inserted a small curved tube in one commissure of the lips, connected by a flexible pipe with the air-chamber of the gauge. This did not interfere with the holding of a reed instrument by the central part of the lips, and a series of notes being produced, showed the scale of pressure actually corresponding to each. From a table compiled by average of many experiments, the following pressures were obtained :-

These facts, he considered, besides their importance in a musical point of view, and to organ builders, were of essential medical significance.

The flute, an ancient instrument, especially in the form of the flageolet, or penny whistle, was then described, and its varieties of conical and cylindrical bore, of ordinary and Boehm's fingering adverted to. Its powers were illustrated by a Sonata of Kuhlau, the most distinguished composer for the instru

ment.

The first reed instrument shown was one which we had all probably long performed on in innocence of its principle, namely, the child's trumpet; this, though limited to the production of a single note, contained a reed in all respects similar to those of the organ. The bagpipes contained several reeds: one, "the chaunter," possessing a scale of a rude kind without semitones; the others, "the drones," forming a chord of single notes.

The oboe, a double reed, was probably the classical "tibia" of which Horace speaks at length; and was also apparently in use in Judæa in Our Lord's time, since, in the curious quotation from St. John's Gospel, xii. 6, it was said of Judas Iscariot that rò yλwooókoμov xe, where the word translated "bag" in our version really means reed box. In medieval times there was a whole family of oboes, called pommers; the lowest, called brummer, corresponding to the modern bassoon.

After a cantiléne on the oboe, the clarinet was considered-a single reed, invented at Nuremberg in 1690. From its cylindrical bore, and from its scale being founded on the interval of a twelfth, its compass was very large, extended moreover by the habitual use of three instruments in the orchestra. Weber's grand Concertante Duet was given in illustration of its capabilities.

The French horn, the next in position on the musical scale, was next adverted to, its series of harmonic or open sounds named, its property of "crooking" in every key explained, and its varieties of "hand horn" and "valve horn" compared; a melody of Donizetti showing its beauties. Lastly, the bassoon, a double reed, essentially a bass oboe, was stated to have been invented in 1539, by Afranio, a Canon of Ferrara, and its powers were exhibited in a Concerto by Felicien David.

Attention was incidently drawn to the contra-fagotto, or double bassoon, an instrument which of late has undeservedly gone out of use, though appreciated and well written for by Bach, Haydn, Beethoven, and Mendelssohn. A fine specimen of the kind, just received from Germany, was shown, and the remarkably low compass of its register, six whole notes below the double bass of the English orchestra, was pointed out.

Two concerted pieces for wind instruments were given: at the beginning of the Lecture, Reicha's fine quintett for the five above-named, without accompaniment; and at the conclusion, Beethoven's immortal work for the wind quartett and piano.

In the course of the evening the Lecturer expressed his satisfaction in being able partially to repay the deep obligations he was under to the old and useful Institution in which he had himself learned the rudiments of physical

science.

[W.H.S.]

Professor Huxley has, it is stated, accepted the office of President of the Birmingham and Midland Institute, held in 1869 by Mr. Charles Dickens.

The Worshipful Company of Grocers have voted the donation of £100 to the funds of the National Hospital for Consumption and Diseases of the Chest, on the separate or cottage principle, Ventnor, Undercliff, Isle of Wight. The Scriveners' Company have subscribed £50 to the fund being raised for the completion of the interior of St. Paul's.

VARIA.

Chemical Society.-At a meeting of this Society on Thursday, January 19, Prof. Olding, F.R.S., being in the chair, Dr. Henry E. Armstrong, Professor of Chemistry in the London Institution, read a paper "On the Action of Sulphuric Acid on the Natural Alkaloids." On heating Narcotine with sulphuric acid diluted with an equal volume of water, over the water-bath, and subsequently adding ammonia to the mixture, he obtained a body which at once exhibited the properties of dimethylnornarcotine, the base which Matthiessen and Wright had produced by the action of hydrochloric acid on narcotine. The reaction is represented by the following equation :

CH_NO, + H2SO = C, H, NO, + CHISO

22 23

7

2

4

From this result the author concluded that narcotine can no longer be regarded as an amide according to the view of Gerhardt and Laurent. On treating Codeine in a similar manner, and dissolving the base in hydrochloric acid, a crystalline hydrochlorate was obtained. This, on analysis, was found to be hydrochlorate of codeine. The first action of sulphuric acid, therefore, results in the production of an isomeric codeine. By the further action of sulphuric acid, a molecule of water is removed from two molecules of codeine, then one molecule of water from one of codeine, and finally the remarkable emetic, apormorphine, seems to be formed. On this point, however, Dr. Armstrong hopes to obtain further evidence.

Hunterian Society.-The Annual Oration will be delivered at the London Institution, on Wednesday, the 8th inst., by Thomas B. Crosby, Esq., commencing at eight o'clock. On Friday, the 10th inst., the members and friends of the Society will dine together at the London Tavern, Bishopsgate-street, to celebrate the Fifty-second Anniversary of the Society. The chair will be taken by Jonathan Hutchinson, Esq., at six o'clock precisely.

Obituary.-On New Year's day, Mr. Alexander Munro, the well-known sculptor, died at Cannes.-On January 10, Mr. John Abel Smith, of the firm of Smith, Payne, and Co., died at the age of 68. He was M. P. for Chichester from 1831 to 1859, and from 1863 until his death.—The Very Rev. Henry Alford, Dean of Canterbury, died on January 12, after three days' illness.—At Corsham, on January 13, Dr. Thomas Mayo, F.R.S., died at the advanced age of 81. He was formerly President of the Royal College of Physicians, and will be remembered as a distinguished writer on mental pathology.—On January 18, Sir George Hayter, principal painter in ordinary and portrait painter to the Queen, died at the age of 78.-On January 19, died Sir William Denison, brother of the Speaker of the House of Commons, and of the late Bishop of Salisbury. Sir William was a man of remarkable energy, and had occupied many high posts in the Colonies. He was appointed Lieutenant-Governor of Van Dieman's Land in 1846, when he received the honour of knighthood. He was subsequently Governor-General of New South Wales, Governor of Madras, and temporary Governor-General of India. The latter position he held from the death of the Earl of Elgin to the arrival of Sir James Lawrence in January, 1864.

New Periodicals.-At the commencement of the year two periodicals, which seem fitted to survive "the struggle for existence," made their first appearance. One is described as a "London newspaper for English readers at home and abroad," and is well named The Week's News. Its contents are cleverly compiled, and may be said to represent the highest style of paste-andscissors' work. The second venture referred to is a new medical journal, to be published monthly, by Messrs. Bailliere, Tindall, and Cox. It is named The Doctor, and its chief object is "to furnish, in the smallest possible compass, an epitome of the practice and literature of the medical profession at home and

abroad." We do not think the title a happy one, although its defenders define it as "the one word that is co-extensive with the profession."

British Association for the Advancement of Science.-The next annual meeting of this Association will be held at Edinburgh, commencing on Wednesday, August 2, 1871. The President-elect is Sir William Thomson, M.A., LL.D., D.C.L., F.R.S., Professor of Natural Philosophy in the University of Glasgow.

Balloons. When Mr. Glaisher, in company with MM. Flammarion, De Fonvielle, and Tissandier, projected this volume of Travels in the Air, he and his collaborateurs little dreamt that before their work could be printed and published the time long hoped for and almost despaired of by aëronauts should at last have come. Mr. Glaisher writes on the opening page:

:

"In its present form the balloon is useless for commercial enterprise, and so little adapts itself to our necessities, that it might drop into oblivion to-morrow, and we should miss nothing from the conveniences of life."

This could not be said now. The balloon has become something more than a philosopher's toy or a raree-show; the nation which invented it has found it an indispensable resource in a desperate emergency, and the political, commercial, and private ends it has served could have been gained in no other way. Only par ballon monte could Gambetta have escaped to the provinces, where his sanguine and energetic spirit has for so long organised-not, indeed, victory-but a sanguine and energetic resistance; only par ballon monte can thousands of Frenchmen hope to hear of all that is nearest and dearest to them; and, if the war and balloons ended together to-morrow, the latter have deserved so well of their country that the city of Paris, under the new Republic, or whatever it is to be, ought to charge its shield of arms with "on a field azure, a balloon rising." -Times.

The Charterhouse. On the 17th ult., Dr. Currey, who has filled the office of Preacher since 1849, was elected Master of the Charterhouse.

Marlborough College. The Rev. Frederic W. Farrar, M.A., F.R.S., late Fellow of Trinity College, Cambridge, Assistant Master of Harrow School, and one of Her Majesty's chaplains, has been elected Master of Marlborough College.

London Livery Companies.-After taking some pains to form a moderate opinion, the Economist has arrived at the conclusion that "the surplus revenues of the London Companies cannot be less than one hundred thousand pounds sterling per annum, and in all probability are very much more. The Economist thinks that these "vast and growing surplus revenues constitute an ample and unexplored fund for promoting technical and higher education."

A Persian Manuscript of great beauty, containing 60 full-page miniature illuminations, and profusely ornamented throughout in the highest style of ancient art, was recently sold by Messrs. Puttick and Simpson, of Leicestersquare, for £205.-Times.

Daily Newspapers.-The Printers' Register computes that there are 110 daily newspapers published in the United Kingdom: 20 in London, 57 in English provincial towns, 2 in Wales, II in Scotland, 19 in Ireland, and I in a Channel island. Sixty-one are penny, and thirty-four halfpenny newspapers.

Educational Books.-The editor of the Publishers' Circular has been collecting information with a view to issuing an index or catalogue, classified according to subjects, of school, college, technical and general educational works in use in Great Britain. So many returns have been already received from publishers, that it would take eight or ten pages, closely printed in three columns, to give the short titles of merely elementary publications which teach the English language. Instead, therefore, of a supplement to the periodical abovenamed, it will be necessary to make the catalogue a distinct volume: it will not, as a general rule, include any work of which there has been no new edition within the last three years.