Obrazy na stronie


The D-Lines Spectra Flame Examined by the Blowpipe. 237 Works, Plant, and other assets 2,890,680 44 marks. , who says “that most of the anthracerse at present in the Liabilities

689,989 28

market is of a very doubtful character." From the com

plaints of our alizarine friends (as brokers in this article) Balance

2,200,691 16

we think the Doctor is quite justified in his scientific con. or about £110,000.--We are, &c ,

clusions; we, of course, can only speak from a business

point of view. We find that the best way to get over the POKORNY, FIELDER, and Co. 15, Fish Street Hill, London,

difficulty is for the consumers to try a ton or so of each November 29, 1876.

producer's make, by which means they become acquainted with the kind of anthracene that suits their working into

alizarine. Both parties obtain mutual benefit. The ali[The name and address of Dr. Versmann was affixed zarine manufacturer can calculate with certainty, and so to the article in question, and bearing in mind that he is avoid heavy losses; the producers, also, can obtain better an authority on the subject of anthracene, and indeed on prices by giving satisfa&tion. Apologising for troubling any branch of the art and science of dyeing; that he is, you,--We are, &c., moreover, a German, and was therefore in a position to

Joseph Bennett Bros. satisfy himself that the sources from which he obtained 22 and 23, Great Tower Street, London, E.C., his information were trustworthy, we did not hesitate to

November 27, 1876. publish his paper. On receiving the above letter we com. municated with Dr. Versmann, and we insert his reply.

DISTILLATION OF SEAWEED. We have examined the copy of the balance-sheet, but we do not find it stated that the £40,000 is the loss during the past three years. We gladly, however, give publicity

To the Editor of the Chemical News. to the fact as stated by Messrs. Pokorny, Fielder, and Co. Sir,-in Dr. Hofmann's report on iodine (see Chemical -Ed. C. N.]

News, vol. xxxiv., p. 215) he speaks of my process having “evidently failed in practice," and that "nothing further

has been heard of the distillation of seaweed, and the proTo the Editor of the Chemical News.

duction of iodine from the residual charcoal." I beg to Sır,-I am obliged to you for communicating to me state that ever since 1863 the process has been worked Messrs. Pokorny, Fielder, and Co.'s letter to you before with great success in the Island of Tyree and other parts its publication, and thereby affording me the opportunity of the West Highlands. The produce of iodine in that of at once replying to it.

island has been increased nearly ten-fold, and I need only These gentlemen, on behalf of the “Chemische Indus- refer to the evidence of His Grace the Duke of Argyll betrie Acien Gesellschaft," at Elberfeld, call my figures in

fore the Privy Council last year to show the remarkable reference to this Company inaccurate, and my observa- benefit to the people of that island. It has not been tions unjustifiable. They point out two errors in the largely extended, because all proprietors of shores are not figures in my article, and to these I will confine myself. so enlightened as His Grace. I stated the loss of the last twelve months' working at

Dr. Hofmann quotes a letter from me, written some £40,000. This information I took from the balance sheet time ago (p. 197), in which the price of iodine is quoted published by the Company in the Cologile Gazette of the at is. 3d. per ounce; it is now only 5 d. per ounce. In a ioth inst., which document is identical with the true copy short paper read before the British Association at their sent to you by Messrs. Pokorny, Fielder, and Co. We are meeting here there are some interesting statistics about now told that £40,000 loss has been incurred during iodine, which I shall shortly send you for publication. three years; but I submit the balance sheet itselt | Meantime, if Dr. Hofmann disbelieves in the existence of allows of but one reading. It is headed, translated, seaweed charcoal, I shall be glad to supply him with a “ Balance-sheet, June 30th, 1876, for the period from thousand tons at a very low rate, and if he can make the July 1st, 1875, to June 30th, 1876," and one of the items order ten times as large it will afford me a proportional of this twelve months' working is put down as £40,000 pleasure to execute it.—1 am, &c., loss. I really cannot be held responsible for any incor

E. C. C. STANFORD. rectness in the official published balance-sheet.

The North British Chemical Company (Limited), The second point refers to the amount of capital, which

149, Hope Street, Glasgow, Nov. 26, 1876. I stated at some £180,000, taking the share capital of £150,000 and debts of £30,000 together in one sum; and | THE D-LINES SPECTRA FLAME EXAMINED if the adding up of these two items, instead of specifying them, should have given any cause for complaint, I truly

BY THE BLOWPIPE. regret my short way of expression. As to my observations generally, I need scarcely assure

To the Editor of the Chemical News. you that I have not been influenced by any unfriendly or

Sir,-I feel so much indebted to your correspondent personal feeling, as I am ignorant of the very names of " NaHO" for calling attention to this important subject any proprietors. But I shall be delighted to learn that I in the CHEMICAL News, vol. xxxiv., p. 226, that I will have drawn too gloomy a picture of the prospects of the waive the obvious advantage he takes by entering upon company under the impression that the £40,000 had been such a controversy under the shelter of an anonymous lost during one year. However, as I am now informed signature, and shall only remark, with reference to the that this adverse result has to be spread over three years, personalities in his letter, that his opinion regarding my I most sincerely trust that this company will not only writings generally can only be of value in the eyes of the soon recover the heavy losses hitherto made, but will in public when his real name, honestly and courageously no distant time become a concern very profitable to the appended to them, shows how much we may attach to it. shareholders.-I am, &c.,

If we are to judge of this value from the contents of the

FREDERICK VERSMANN. anonymous letter, our estimate will not be oppressively 35, Whitecross Place, Wilson Street, Finsbury, E.C.


Let us now weigh the facts adduced by your corres

pondent, and see if they can stand against my tentative ON ANTHRACENE PRODUCTION.

“ series, which,” he rather ungrammatically observes,

"are a fair specimen of the experimental method as fol. To the Editor of the Chemical News.

lowed by chemists." SIR'-Our attention has been drawn to the remarks of Dr. (1.) He tells us that " at a white heat the sodium sal Frederick Versmann (CHEMIT AL News, vol. xxxiv. p. 211), I adherent to platinum wire is volatilised, while at a lowe


Chemical Notices from Foreign Sources.


Dec. 1, 1876. temperature the spectrum is more permanent.” Now, , CuSO4,11-0+2H20, which is formed when crystals of considering that, in the experiment to which this remark blue vitriol are exposed to dry air at 250 to 30°. This new refers, the same platinum wire was used, though inserted hydrate is stable enough to resist a dry vacuum, whilst in different parts of the blowpipe “ Name,” the assertion under the same circumstances the original hydrate loses here made by your correspondent is that the trace of its 4 molecules of crystalline water. sodium, having been first volatilised, is reproduced per

Margaric Chloride and its Derivatives.-A. Villiers. manently by the use of a lower temperature !

-This compound, C32H34C102, was obtained by the action (2.) The argument as to the production of the “D-lines”

of phosphoric perchloride upon the margarate of soda. by the combustion of sodium in a vacuum tube, has been previously well considered by me. No one knows better

Researches on Quercite.-L. Prunier.— The author than the distinguished editor of the Chemical News, who considers that quercite is a compound forming the transihas succeeded more nearly than, perhaps, any man in

tion between the fatty and the aromatic series. Europe in the attempt to obtain it, that the artificial On Angelic Acid.—E. Demarcay.-Not suitable for production of a perfect vacuum is almost, if not quite, an abstraction. impossibility, and, where there is a particle of air, sodium Existence of Asparagin in Sweet Almonds.-L. will, in combustion, derive water. Has your corres- Portes.-Having established the presence of asparagin, pondent tried the experiment himself? If not, let him do the author thinks it evident that in almonds-on account so, and he will find that soda is produced by the combus- of their oily nature-the products of transformation due tion, in spite of his “ vacuum."

to the germinative process appear at an earlier period than (3.) The opalescence caused in pure boric acid by the in other seeds. impingement upon it of the orange flame emitted from platinum is " positive evidence of the absence of sodium Province of Santa Catarina (Brazil).— E. Guignet and

A Meteoric Iron, very rich in Nickel, found in the in (from ?) that fame” when taken in conjunction with the G. Ozorio de Almeida.—The specimen contains 36 per cent other fact mentioned by me, that the orange flame from a

of nickel, and is free from chrome, cobalt, manganese, and sodium salt removes that opalescence.

copper; neither is it mixed with any earthy gangue. (4). The onus probandi of showing that the “ D-lines" are produced by sodium only evidently rests with the

Chemical Composition of the Water of the Bay of sodiumite. The supporter of the water hypothesis has Rio de Janeiro.-E. Guignet and A. Teller.—Silica and only to show (as I consider I have fairly shown) that they alumina are constantly found in considerable amount, are not.-I am, &c.,

even in samples carefully filtered. The water has a W. A. Ross.

decided alkaline reaction, due neither to ammonia nor to London, November 27, 1876.

carbonate of ammonia, but to soda and potassa, present as silicates and aluminates.


CHEMICAL NOTICES FROM FOREIGN Bulletin de la Société d'Encouragement pour l'Industrie

Nationale. No. 34, October, 1876.

Methods employed to Determine the Nature of the

Colouring Matters Introduced into Wines.--A reNote.-A11 degrees of temperature are Centigrade, unless otherwise indigo, which is often used in the shape of sulphate, the

port by MM. Balard, Pasteur, and Wurtz.- To detect expressed.

authors add a little sulphate of potassa, and precipitate

with chloride of barium. The sulphate of baryta, after Comptes Rendus Hebdomadaires des Seances, de l'Acadenie filtration and washing, appears white if the wine is free des Sciences. No. 20, November 13, 1876.

from indigo, but if that dye is present it has a decided blue Mineralogical and Geological Researches on the tint. Magenta is probably never employed alone in the Lavas of the Dykes of Théra.-M. Foqué.— Тne present fraudulent coloration of wines, but

along with indizo it can paper is a report by MM. Chasles, Sainte-Claire Deville, be made to produce vinous reds. To detect this dangerous Des Cloiseaux, and Daubrée. It appears that in all the impurity the authors agitate the suspected wine with a lavas of Théra there are at least two, and often three, small quantity of amylic alcohol. This withdraws the triclinar felspars. The predominant felspar (among the dye, and collects upon the surface of the wine, where it microlithes) is albite, but among the larger crystals it is forms a bright red stratum. If this rose-coloured liquor sometimes labradorite, and sometimes anorthite. The is treated with a small piece of clean white silk, not morlabradoric lavas free from olivine and rich in tridymite danted, the latter takes the well known shade of magenta, contain a ferruginous pyroxene, and have a proportion of which turns yellow if the silk is touched with a drop of silica intermediate between those of the acid and the hydrochloric acid. An appendix by Dr. Stierlin gives a basic lavas. The anorthitic lavas in which olivine is tabular view of the behaviour of different reagents with abundant and tridymite rare contain very little silica, and wines coloured with dyes as compared with pure red wine may be regarded as basic rocks.

Influence of Temperature upon Magnetisation.M. J. M. Gaugain.-In operating upon a bar of steel

MISCELLANEOUS. capable of undergoing a considerable transient variation the magnetism is much weaker at 300° than at the ordinary temperature. When, on the contrary, the transient varia.

Organisation among Chemists.—The committee tion of the bar is very small, the magnetisation is more appointed to take this matter in hand met for the first powerful at 300° than at a lower temperature.

time on Saturday, November 25, at Burlington House.

There were twenty-eight members present. The following Hydrates of Copper Sulphate.-M. L. Magnier de gentlemen were elected Officers of the Committee :-Dr. la Source.-Copper sulphate presents several distinct | Frankland, Chairman; Dr. Williamson, Prof. Abel, and degrees of affinity (or water corresponding to the Dr. Voelcker, Vice-Chairmen; Dr. c. R. A. Wright, hydrates

Treasurer ; Mr. W. N. Hartley, Secretary. The names CuSO4,H20 (constitutional water).

of Prof. Dittmar, of Glasgow, and of Dr. Graham, of UniCuSO4H2O + H20.

versity College, London, were added to the Committee, CuSO H20+4H20.

but it was decided that for the present no further additions CuSO4H20+5H20.

should be made. A sub-committee of seven Members was CuSo H20+6H2O.

appointed to prepare a draft scheme for the consideration o complete this series must be added the hydrate, of the General Committee upon which the constitution and



[ocr errors]


The Royal Society. Dec. 1, 18;6.

239 rules of the new association may be founded. The follow

BISULPHIDE OF ing were nominated by ballot to serve on this committee :

Prof. Abel, Mr. Carteighe, Prof. Frankland, Mr. W. N.
Hartley, Mr. Neison, Dr. Voelcker, Dr. C. R. A. Wright.

The Royal Society.—Yesterday being St. Andrew's

RED OXIDE, Day, the Anniversary Meeting of the Royal Society was

OXYCHLORIDE held. The following Officers were elected for the ensuing

Sulphocyanide, year :

President, Joseph Dalton Hooker, C.B., M.D., D.C.L., And every other Mercurial Preparation.


Oxysulphuret of Antimony, Glacial Acetic Acid, Secretaries—Prof. George Gabriel Stokes, M.A., D.C.L.,


PercHLORIDE of IRON, LL.D.; Prof. Thomas Henry Huxley, LL.D.

SULPHITE AND HYPOSUL. Foreign Secretary-Prof. Alexander William William. SULPHIDE OF IRON,

Pure Acids,


CHLORIDE OF SULPHUR, PHOSPHATES OF SODA AND Other Members of the Council-Major-General John T.


AMMONIA, Boileau ; Warren De la Rue, D.C.L.; Prof. P. Martin


ETHERS, Duncan, M.B., P.G.S.; Prof. William H. Flower, F.R.C.S.;


BROMIDES, Prof. Michael Foster, M.D.; Edward Frankland, D.C.L.;


IODIDES, Francis Galton, M.A.; William Augustus Guy, M.B.;


SCALE AND GRANULAR PREJohn Russel Hind, F.R.A.S. ; The Rev. Robert Main,

PARATIONS. M.A.; William Pule, C.E., Mus. Doc.; The Rev. Bartho. Fruit Essences for Conlomew Price, M.A.; Rear-Admiral G. H. Richards, C.B.;

FECTIONERY & LIQUEURS, Henry Clifton Sorby, Pres. Mic. Soc. ; Prof. Henry J.

ALSO, Stephen Smith, M.A. ; Prof. Balfour Stewart, M.A.

Pure Photographic Chemicals of every kind.



MONDAY, 4th.-Society of Arts, 8. (Cantor Lectures.) "The History

of the Art of Coach Building," by Mr. G. A. Thrupp.
Lecture III.-Carriages from 1770 to the present

Medical, 8.

Royal Institution, 2 (General Monthly Meeting).

London Institution, 5. TUESDAY, 5th.-Civil Engineers, 8.


ogical, 8.30. WEDNESDAY, 6th.-Society of Arts, 8. " Street Tramways," by Cap

tain Douglas Galton, R.E., C.B., F.R.S.

Geological, 8.
Microscopical, 8.

Pharmaceutical, 8.
THURSDAY, 7th.-Royal, 8.30.

Chemi:al, 8. "Analysis of a Species of Erythro- Makers of every description of Chemical, Colliery, Copper Ore, Gold

phyil," by Prof. Church. "On Phenylendiamin," Mining and Glass Machinery, including Crown, German Sheet, and
by Dr. Witt. "On Calcium Sulphate," by Mr. Plate Glass Plant, as supplied to some of the largest Firmsin Engiand,

Ireland, Scotland, and Wales.
Royal Society Club, 6.30.

Makers of the latest Improved Revolving Black Ash Furnace FRIDAY, 8th.-Astronomical, 8.

with Siemens's Patent Gas Arrangement, and as used in the Manufac. Quekett Club, 8.

ture of Soda.

Improved Valveless Air Engines, and Pumps or Acid Forcing, Air S. A. SADLER,

Agitators, Compressors for Collieries, and Weldon's Patent Chlorine

CLEVELAND CHEMICAL WORKS, Caustic, Chlorate, Decomposing, and Oxalic Pans.

Gas Producers for Heating Furnaces.

Pyrites Burners for Irish, Norwegian, and Spanish Ores.
Newfali Tar Works, Carlton;

Retorts, Acid Gas, Nitre, Nitric Acid, and Vitriol Refining. and Ammonia Works, Stockton-on-Tees.

Improved Steam Superheaters for Resin Refining, &c.
Improved Steam Sulphur Pans.



[ocr errors]


Solvent and Burning Naphthas, Carbolic Acid and Disinfecting
Powder, Refined Anthracene, Naphthaline, Black Varnish, Refined
Tar, Crude Liquid Ammonia, Galvanising Salts, Coal-Tar, Pitch
Creosote, Grease, &c., &c.

S.A.S. is always a buyer of Coal-Tar Naphthas, Crude Anthracene
and all Tar Products.
All communications to be addressed to the offices at Middlesbrough.


[merged small][ocr errors][merged small]

Cleadon Chemical Works, Newcastle-on-Tyne.
Also Rock Specimens, British and Foreign Shells,

Crustacea, Microscopic Objects, Glass

Capped Boxes, Card Trays, Tablets, &c.
Specimens sent for Sele&ion to known or approved applicants.


Catalogues Free,

Graham's Improved Burner Pipe, a sure preventative against the
Destruction of Lead in Towers and Chamber Ends, and a Perfect
Remedy against any Escape of Gas.

11 kinds of Acids Supplied at Remarkably

Distance no object; at Sender's risk; Carriage Paid-Apply to SUTCLIFFE BROS., Climax Works, Birkenhead.

1, 1876.


240 Advertisements.




Wholesale and Retail Chemists,


Has a Speciality in



Pure and Commercial, at Market Prices.
LUMP, of every percentage for Chemical and every requirement.
CRYSTALLISED, Selected Lumps, and Ground, for all purposes.

Pri e List post free on application.
GROUND, in Water and Dry, and Black Oxide.
PREPARED, for colouring Tiles, Pottery Ware, &c.

109 111, BETHNAL GREEN ROAD, ARSENIC, White Refined powdered, Lump, Grey, and Ruby.

FLUOR-SPAR, the finest produced, for Opal, Acid, and Flux.
CARBONATE OF BARYTES, Selected Lump and Ground.
BAUXITE, Magnesite, Emery Stone, Chrome Ore, English, Italian,
and FRENCH CHALK, China Clay, Flints, Cryolite, and

all other MINERALS, ORES, &c.

Wholesale and Export Dealers and Manufacturers of Supplies by Contract and in large and small quantities, at the lowest rices, direct from Mines or Works, or from stock held at the CHEMICAL & SCIENTIFIC APPARATUS Manganese Oxide and Mineral Works, Garston. Graduated Instruments, Pure Chemicals, &c.,

For Analysis and the general Laboratory Use of Manufacturers

Mines, Universities, Schools, &c.,
Sutton Oak Manure Works,

89, Bishopsgate Street Within,

LONDON. ST. FT ELENS, LANCASHIRE Sole Agents for Prof. Wanklyn's Test Solutions or Water Analysis MANUFACTURERS OF

Illustrated Catalogue post free on receipt of 3 stamps.

EXTRACT OF MEAT per cent Soluble (guaranteed),

Finest Meat-flavouring Stock for Soups, Mede-Dishes

and Sauces. Caution.-Genuine ONLY with facsimile Commercial Phosphoric Acid,

of Baron Liebig's signature across Labei. PATENTS.-Mr. Vaughan, F.C.S., British

Foreign, and Colonial PATENT AGENT. Special attention given to Inventions relating to Chemistry, Mining, and Metallurgy.

Guide to Inventors" Free by Post.-Ofhces, 67, Chancery Lane, Phosphatic Gypsum.

London, W.C., and 8, Houndgate, Darlington.


[ocr errors]

Concentrated Superphosphate of Lime, LIEBIG COMPANY'S







in conjunction with the SCIENTIFIC DEPARTMENT of the


Instruction and preparation in CHEMISTRY and the EXPERI

MENTAL SCIENCES under the direction of Professor E. V. SMALL SIZE,


The Class Rooms are open from 11 to 5 a.m. and from 7 to 10 p.m.
Especial facilities for persons preparing for Government and other
Private Pupils will find every convenience.

Analyses, Assays, and Practical investigations connected with

Patents, &c., conducted.

Prospectuses and rull particulars on application to Prof. Gardner

at Berner's College, 44, Berners-street, W., or at the Royal Poly.



STREET, offers Jewellers, Mineralogists, Lapidaries, and WITH THE FURNACE Cold. The loss of heat by radiation is uil, the specially Collectors of Rare Cut Gems (which he possesses in all outer casing remaining absolutely cold. Its power is limited only by existing kinds), large Collections of Fine Hyacinths in all Colours, the capability of resistance to fusion of the refractory casing. Half a Clear Spanish Topazes, Blue and Yellow Amethysts, Jargon, pound of steel can be melted and poured in less than twenty minutes. Olivine, Fossils, Fine Collections of Shells, Thousands of Indian It is absolutely secure against loss by boiling over or cracking of a Pebbles. Polished Agates, &c., Starstones and Catseyes, Garnets, crucible in the melting of valuable metals, &c., and turns out sounder Cape Rubies, Fine Slabs of Lapis Lazuli, Fine Emeralds in the and tougher ingots of gold, silver, &c., than any known furnace. Matrix, Fine Crystallised Rubies and Brazilian Topazes, and

Hot-Blast and other Blowpipes, Special Gas Furnaces with and Thousands of Rare Opals. Specimens and for Cuttings. Orders without blast for Spectroscope Analysis, Cupelling, Enamels, Roasting effected to all parts of the world. Ores, &c. Burners and Blowpipes for all temperatures from that or a drying closet to the fusion of platinum. Foot-blowers giving any INDIA-RUBBER SPECIALLY PREPARED FOR required pressure of air with perfect steadiness up to 4 lbs. on the square inch. Special designs to order without extra charge. Detailed

CHEMICAL PURPOSES. list with engravings on application to THOS. FLETCHER, F.C.S.,

Boots, Gloves, Gauntlets, Aprons, Pure Tube and Museum STREET, WARRINGTON, Manufacturer of Platinum Alloys, Oxychloride of Zinc, &c., for Dentists. (See Loan Collection of

Hose, all Warranted Best Quality. Scientific Apparatus, South Kensington, Section 8.

J. G. INGRAM & SON, 1. HEADLY, ENGINEER, Cambridge, Manufacturers of Mechanical, Surgical, Chemical, and

Maker of Steam Engines, Bone Mills, and other Machinery all other Vulcanised India-Rubber Goods. for Chemical Works; also Whole and Ground Coprolite.

The London India-Rubber Works, Hackney Wick, E.,

W. HART, Manufacturer

and Dealer

in Trade only.

Apparatus and Chemicals for Scientific Pursuits. Latora.

tory Fitter and Furnisher. Photographic Apparatus and Materials. SQUARE, LONDON, E.C. 8, KINGSLAND GREEN West Side), LONDON.

[ocr errors]

Electrical and Philosophical Instrument Maker to the F.

Dec. 8, 1876.
Repulsion Resulting from Radiation.


zero, where the spot of light normally rests. The vertical THE CHEMICAL NEWS. figures represent the seconds during which the experi

ment lasted. The zigzag line represents the oscillations

of the spot of light, and shows the movement of the pith VOL. XXXIV. No. 889.

surface under the influence of a uniform source of radiation. The time was recorded by a chronograph. Starting from zero the spot of light is seen to have travelled to

97° in 11'5 seconds ; at the end of 11 more seconds, or ON REPULSION RESULTING FROM

22.5 seconds altogether, it had come back to 50°; at the RADIATION.-PART II.*

end of 34 seconds the light had advanced again to 109°, and so on.

The movements are tolerably uniform as to By WILLIAM CROOKES, F.R.S., &c.

time, taking about 11'5 seconds for the half oscillation, (Continued from p. 230).

but the amplitude of vibration is continually diminishing

107. If, however, the light is only allowed to shine on 106. It was found that when a source of light and heat the pith surface for 11°5 seconds (or for as long as the is suddenly allowed to shine on the pith surface and not spot of light takes to perform its first half oscillation), and removed, a deflection rapidly takes place, attaining its if it is then instantly cut off, the spot of light almost inmaximum in about 11 seconds; the spot of light now variably returns to zero and stops there, instead of swingreturns a few degrees, and then proceeds in the first ing to the opposite side and only returning to rest after direction to a greater extent than at first. So it goes on, ten or a dozen oscillations, as is the case when the beam by alternate steps, advancing a little each oscillation, ) is set vibrating by mechanical means. This behaviour

Fig. 9.

Degrees on scale, representing repulsion.

[graphic][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][ocr errors][subsumed][merged small][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][ocr errors]

until, if the light be feeble, the index takes up a nearly points to the return movement taking place under the fixed position; if, however, the light be strong, the beam influence of a force which remains active after the original is driven against the side of the tube. In illustration of radiation is cut off, and which is only gradually dissipated. this I select the following series of observations from a This force is most probably from the heat which the pith large number recorded in my note-book. The horizontal has absorbed raising its temperature; and the steady figures represent the degrees on the scale, starting from return to zero seems to be due to the movement being

controlled by the radiation of heat by the pith. * A Paper communicated to the Royal Society, March 20, 1875. From the Philosophical Transactions of the Royal Society of London, paratus, with the object of ascertaining the times o

108. A series of observations taken with another apvi clxv., pt.2

« PoprzedniaDalej »