« PoprzedniaDalej »
Chemical Notices from Foreign Sources.
CKWICAL NEW, 1 January 24, 1879.
On Thymo-oxy-cuminic Acid.-L. Barth. The tains per litre 33 grms. molybdic acid, 141 grms. N203 author describes the preparation, properties, and deriva- and 1994 grms. NHg. When precipitating phosphoric tives of this acid at considerable length.
acid the quantity of free nitric acid must always be more On Idrialin.-G. Goldschmiedt.-The author finds than enough to prevent the formation of a precipitate in this body to contain 91'71 carbon and 5'32 hydrogen, and
vdrogen, and the absence of phosphoric acid, but a considerable quan
the absence of phosph declares that he cannot see why it should rank with the l fity of nitrate of ammonia may be dissolved in the liquid. aromatic hydrocarbons.
į In ordinary cases the phosphoric acid will be totally pre.
cipitated in less than twelve hours, if so much molybdic · Double Salts of Cuprous Hyposulphite (Second
mixture is added as to make up tour times the volume of Memoir).-F. Kessel.--Not suitable for abstraction.
the phosphoric solution, and if in every 100 c.c. of the On a-Oxpara-toluylic Acid.--E. v. Gerichten and W.
mixture there are dissolved 25 grms. nitrate of ammonium. Rössler.-The authors pronounce this acid identical with For washing the precipitate is employed a strong solution Flesch's oxy-toluylic acid.
(20 per cent) of ammonic nitrate, to which at first one. Adion of Fuming Nitric Acid and of Nitrous ! thirtieth of its volume of nitric acid is added. The washing Acid upon Benzol-sulphinic Acid.-W. Kanig.–The is completed when the washings are no longer coloured author seeks to ascertain whether C18H16N2S306 contains by potassium ferrocyanide. The precipitate may be intact the three benzol-sulphuryl residues.
brought into a condition fit for weighing by the following On Organic Thio-compounds.-O. Wallach. The operations : -After removing most of the ammonic nitrate author examines the behaviour of alkyl-bromides and by me
od l by means of water the contents of the filter are washed iodides upon natrium-thiacetanilid.
| into a weighed porcelain crucible. Anything adhering to
the paper is dissolved in a little warm dilute ammonia, New Mode of Formation of Phenyl-glyoxylic
the solution is concentrated by evaporation, nitric acid is Acid.-L. Claisen and F. H. Morley. -Ethyl-glyoxylic added in excess, the whole is quickly poured into the ethyl.ether and mercury diphenyl are readily transformed porcelain crucible, the liquid is expelled by evaporation, with little loss into phenyl-glyoxylic ethyl-ether and mer.
and the nitrate of ammonia driven off by a flame cury mono-phenyl-chloride.
moderated by wire gauze. The residue is hygroscopic, On Triphenyl-methan.-E. and 0. Fischer.—The and must be cooled over sulphuric acid and quickly authors have obtained from this compound both tri- | weighed in the covered crucible. phenyl-methan-cyanide and triphenyl-acetic acid. They Diazo-compounds of the Fatty Series (First Memoir). effected this object by heating triphenyl-inethan-chloride -W. Zorn.-.By treating ethyl-iodide with silver nitrosyi with an excess of mercury cyanide.
the author obtained a compound C2H5NO, almost as Action of Halogens upon the Salts of Guanidin. readily and as violently explosive as the chloride of -). Kamenski.-In this memoir the author examines the nitrogen. behaviour of guanidin carbonate with bromine and chlorine. | Discovery of Vanillin in Siamese Benzoin.-P.
Chrysarobin and Alleged Chrysophanic Acid in Jannasch and C. Rump.-This paper contains merely the Goa-powder.-C. Liebermann and P. Seidler.--The analytical evidence that the substance detected was vanillin. authors hold that the substance originally present in this Preparation of Nitrous Acid.-G. Lunge. For the powder is not chrysophanic acid, and that acid, as actually
preparation of nitrous acid, whether by means of arsenious detected by Attfield, they consider a product of conversion.
acid or starch, should be used nitric acid of sp. gr. I'30 to For the original substance they propose Attfield's synonym
1-35, and almost entirely free from hyfonitrous acid. chrysarobin.
Ation of Ethyl Iodide upon Silver Maleate and Synthesis of Anthrarufin and Chrysazin from Fumarate.-R. Anschütz.-The author's object is to Anthracen.--C. Liebermann.-On treating anthracen decide the isomerism of maleic and fumaric acids by a with sulphuric acid the authors obtained two disulpho.
sulpho comparative study of their derivatives. . acids, one of which lead through an easy series of con- i versions to anthrarufin (Schunck and Römer) and the
On Alizarin Blue.-C. Græbe.-The author shows by
his experiments that the corre& formula for this com. other to chrysazin.
pound is C,H2NO, By heating it with zinc-powder he Disulphanthracenic Acid and its Conversion into
obtains a new base, CA HIIN, whose salts are all goldea Anthrarufin.-C. Liebermann and K. Boeck. A detailed
yellow, and in solution display an intense green fluoresdescription of the former readion mentioned in the pre
cence. vious paper.
Simple Method for Obtaining the Aldehydins.-A. Formulæ of Rhamnetin and Xantho-shamnin.-C.
Ladenburg.-The author agitates dilute aqueous solutions Liebermann and O. Hörmann.—The authors assign to
of an ortho-diamin hydrochlorate with an aldehyd, when rhamnetin the formula C12H160s, and to xantho-rhamnin
the corresponding aldehydin is formed with liberation of C48H66022
heat. Certain Derivatives of Cærulignon.-H. Ewald.
Experimental Determinations of Position.-A. A description of hydrocærulignon potassium, hexa.
| Ladenburg.-Not suitable for abstraction. methoxyl-diphenyl, dibrom-hexa-methoxyl diphenyl, and
On Certain Phenyl-aldehydins.-A. Ladenburg and dichlor-hexa-methoxyl-diphenyl. Three Isomeric
T. Engelbrecht.-An account of phenyl-benzaldehydin Tolidins.-A. Goldschmidt.
in and phenyl-furfuraldehydin.
In addition to the tolidin obtained by Petriew the author has obtained two others. The paper contains an account of
On the Aldehydins.-A. Ladenburg.-The author meta-azo-toluol, meta-hydrazo-toluol, and sulphate of
describes dibenzyliden-amido-benzoic acid; tolufurfur.
aldehydin, which latter body possesses an intense bitter tolidin. On Hydrocarbons obtained by the Action of Alu.
taste recalling that of strychnin and acts upon animals as minium Chloride upon Chlor-methyl and Benzol. a powerful poison ; and, lastly, phenyl-anisaldehydin. E. Ador and A. Rilliet.-An examination of xylols.
Naphtho-picric Acid and Certain of its Derivatives. Determination of Phosphoric Acid as Ammonic T. Dichl and V. Merz. The authors describe the prePhospho-molybdate.-R. Finkener.-Hydrochloric and para
and | paration of this acid and the following of its derivatives : nitric acids hinder or delay the formation of the yellow
1-Amido-diimido-naphthol hydrochlorate, the chromate
precipitate, whilst dissolved molybdic acid promotes or of the same name, and the platinic double salt. accelerates it. Hydrochloric acid in the solution acts more The Formula of Uric Acid.-H. B. Hill.—The powerfully than nitric, and ammonic nitrate more power-author admits an error as to the originai authorship of a fully than ammonic chloride. The author's solution con- structural formula.
Tétra-nitroxy-sulpho-benzide.--J. Annaheim.-This 5420 pp., Royal 32mo., French morocco, gilt edges, price 58., compound, C12H6N,SO12, is a solid, straw.coloured body, A POCKET. BOOK FOR CHEMISTS of an intensely bitter taste, melting at 253°, and della | n CHEMICAL MANUFACTURERS, METALLURGISTS grating at higher temperatures.
DYERS, DISTILLERS, BREWERS, SUGAR. REFINERS
PHOTOGRAPHERS, STUDENTS, &c., &c. By THOMAS BAYLEY, On Mucobromic Acid.-0. R. Jackson and H. B.
Assoc, R.C. Sc. Ireland, Analytical and Consulting Chemist, Demon Hill.-An account of the preparation and of certain de. strator of Practical Chemistry, Analysis, and Assaying, in the Mining rivatives of this acid.
Synopsis of Contents. Analysis of the Mineral Spring Marienbrunnen, at Atomic Weights and Factors-Useful Data-Chemical Calculations Huckstelle, Westphalia.-H. Vohl.
--Rules for Indirect Analysis-Weights and Measures-ThermoAnalysis of the Bitter Water of Rákóczy, from
meters and Barometers-Chemical Physics-Boiling points, &c.
Solubility of Substances-Methods of obtaining Specific GravityBuda.-H. Vohl. The interest of these two papers, if Conversion of Hydrometers-Strength of Solutions by Specific Graany, is medical rather than chemical.
vity-Analysis-Gas Analysis-Water Analysis-Qualitative Analysis and Reactions-Volumetric Analysis-Manipulation - Mineralogy Assaying - Alcohol - Beer --Sugar - Miscellaneous Technological
Matter relating to Potash, Soda, Sulphuric Acid, Chlorine, Tar Pro. NOTES AND QUERIES.
ducts, Petroleum, Milk, Tallow, Photography, Prices, Wages, &c.
London: E. and F. N. SPON, 46, Charing Cross. Gluten in Grain.-Will any of your readers inform me what grain
New York : 446, Broome Street. contains the largest amount of gluten ?-R.
CARBOLIC, AURINE, PICRIC, COLOURS AND
A Chemist, with satisfactory testimonials as to
years experience in the sole management of two Works, and full SATURDAY, 25th.-Physical, 3. “Studies in Vibration," by Dr. F.
knowledge of business connection, &c., is open for an Engagement. Guthrie, F.R.S.
To any gentleman with capital can offer good prospects of a very pro. MONDAY, 27th.-Medical, 8.30.
fitable return for money invested.-Apply, J. Loogshaw, Penketh, acar. Royal Geographical, 8.30.
A Gentleinan having had Six Years' Experience
in Analytical Chemistry desires an engagement as Assistant, TUESDAY, 28th.-Civil Engineers, 8.
or as Chemist in Works.-W.H., Torwood Lodge, Pellatt Grove, Anthropological, 8.
Wood Green, N. = Royal İnstitution, 3. “Animal Development," Prof. Schäfer.
Manager of Tar and Ammonia Distillery will WEDNESDAY, 29th.-Society of Arts, 8. “The Distribution of Dis. y be disengaged on February jo, and will be open for Re-engage
ease Popularly Considered," by A. Haviland, ment Advertiser has a good practical knowledge of the business, MR.C.S.
and is a steady energetic man.-Address No. 60, CHEMICAL NEWS THURSDAY, 30th.-Royal, 8.30.
Office, Boy Court, Ludgate Hill, London, E.C.
The Authors of “ A Practical Treatise on the
with scarly 100 new illustrations (Sampson, Low, and Cr., 188, Fleet FRIDAY, 31st.-Royal Institution, 9. "Logic of Architectural Design," Street, E.C.) are prepared to furnish plans and advice and superintend by Mr. H. H. Statham.
the creation of plant in all parts of the world.-Address, L. and L., — Society of Arts, 8. "Quest and Early European CHEMICAL NEWS Office, Boy Court, Ludgaté Hill, London, E.C. Settlement of India," by Dr. Birdwood, C.S.I.
stitution, 3. "Reptilian Life," Prof. Situation wanted by a Competent Analyst as H. G. Seeley.
Assis'ant or Principal. Good teacher. Apply, Public Analyst,
CHEMICAL News Ofice, Boy Court, Ludgate Hill, London, E.C. THE
W anted, to exchange complete numbers of QUARTERLY JOURNAL OF SCIENCE. "Nature" for 1878 for complete CHEMICAL News for same
period, in good condition.-Apply to M., CHEMICAL News Once, Box
Court, Ludgate Hill, London, E.c.
W anted, a Foreman in Superphosphate
Works. Capable of undertaking the making of Sulphuris
Acid and mixing. First class references required. He must be a CONTENTS.
married man. Apply to Edward Toynbee, Saxilby, Lincoln. 1. On the Thickness of the Antarctic Ice, and its Relations to
- MANUFACTURING CHEMIST. that of the Glacial Epoch. By James Croll, LL.D., F.R.S. II. Gravitation as a Factor in the Organic World. By William Wanted, a Young Man having a Good Know.
ledge of Practical Chemistry. Must have been used to the
Manufacture of Chemical Products. --Address, stating wages expected, Future. By Albert R. Leeds, Ph.D.
experience acquired, and all particulars, to Chemist, care of Messrs. IV. The Course of Nature. By Prof. Simon Newcomb. V. Peruvian Antiquities. By E. R. Heath, M.D.
Gi Street and.Co., 30, Cornhill, E.C. · Notices of Scientific Works, Obituary, &c.
W ater-glass, or Soluble Silicates of Soda
WV and Potash, in large or small quantities, and either solid
or in solution, at ROBERT RUMNEY'S, Ardwick Chemical NOTICE.
WILLIAM AND WILLIAM T. FIELD. THE JOURNAL OF SCIENCE. MANUFACTURERS of the Celebrated The JOURNAL OF SCIENCE will in future be issued MONTHLY I STAFFORDSHIRE BLUE BRICKS, specially adapted for instead of QUARTERLY, and will consist of 48 pp., the form and Chemical Plant, i.e., Acid Towers, &c. Also all other kinds of Best general appearance remaining the same.
Staffordshire Blue Bricks, Pavings, Plynths, Splays, Copings, &c.
&c. Prices and samples on Application,
“We have used the Blue Staffordshire Brick for Sulphuric Acid
Towers, &c., manufactured by Messrs. Field, for the last fifteen years, In addition to the usual articles on sub iects of present scientific
during which time they have given great satisfaction. We recommend
during which time thau have interest and reviews of scientific works, the MONTHLY JOURNAL OF them to the Chemical Trade, believing there is nothing better in the • SCIENCE will contain abstracts of papers read before the Scientific market."-(Sigoed) WILLIAM HUNT and SONS, Lea Brook Societies - Reports on all Important Scientific Discoveries -A Alkali Works, near Wednesbury, Staffordshire, February, 1878. General and Critical Review of the Results of Biological Research
TOLL END BRICKWORKS, “Notes and Queries " and "Correspondence" Columns, &c., &c. Londod: 3, Horse-Shoe Court, Ludgate Hill, E.C.
1 January 24, 1879. THE NEW FASHION OF USING | 4. If kept in a dry place the preparations will
at Home Dyes Prepared Free from keep for years.
Arsenic has not yet met with the appre- 5. The retail price of the packets is 3d. and 6d. ciation it deserves. There is consequently still each, but the following discount will be a great deal to be done before it will be properly allowed :introduced to the Public, by whom it is at pre
40 per cent to purchases amounting to 50s. sent very little known, but by whom it could easily be learned, as it is so practical and
» Over 50s. and under 99s. 50 ,
, over £5. exceedingly simple in its application.
Terms Cash. I therefore now take the liberty to call attention to the under-mentioned advantages which For the approaching Easter Festival I beg to this article offers for every household, and re-recommend my EGG - DYES in different commend it strongly to the Trade as an easy colours, such as Rose, Sky-Blue, Yellow, selling and good paying thing.
ORANGE, and Carmine. 1. All my preparations are entirely free of They are entirely free from Poiso poison, and possess a very considerable intensity | splendid hue, in little packets with complete and beauty of colour.
directions. 2. The dye preserves its different colours in | Price id. each, with equivalent reductions. wool, half-wool, cotton, and silk in a degree not My preparations decidedly deserve the preyet attained by any other preparation.
ference to all other articles of the kind as yet 3. The dye is made up in small packets of brought before the public notice, on account different colours, ready for sale, and in order to principally of their purity and brilliancy of facilitate each colour being distinguished, every colours, and as they are composed of only the packet has the complete instructions how to use best materials the colours are of unequalled the dye printed on it in the same colour. intensity.
SAMPLES OF DYED WOOLS ARE TO BE HAD GRATIS OF
HER MANN FRA HNERT,
DAVIS'S NITROMETER, 15/.
DAVIS'S OXYGEN TUBÉ, 6).
MOTTERSHEAD & CO.,
IMPORTERS AND DEALERS IN
CHEMICAL & PHYSICAL APPARATUS,
7, Exchange Street and 10, Half Moon Street, Sulphocyanide,
MANCHESTER. And every other Mercurial Preparation. BISULPHITE OF LIME, TETRACHLORIDE OF CARBON. | Illustrated Priced Catalogues Six Penny Stamps. Orders over 403
accompanied by a remittance are delivered Carriage paid at any Oxysulphuret of Antimony, Glacial Acetic Acid,
Railway Station in England. LIQUOR AMMONIR,
PERCHLORIDE OF IRON, SULPHIDE OF IRON, SULPHITE AND HxPosul. JAMES WOOLLEY, SONS, & CO., PURE ACIDS,
PHITE OP SODA, CHLORIDE OF SULPHUR, PHOSPHATES OF SODA AND
69, MARKET STREET, MANCHESTER, ACETONE, AMMONIA,
CHEMICAL AND SCIENTIFIC APPARATUS
CHEMICAL REAGENTS, &c.,
FOR THE USE OF
SCALE AND GRANULAR PRE. Lawrevers Snience Te
ULAR PRE. | ANALYSTS, SCIENCE TEACHERS, AND MANUFACTURERS
Price Lists on application.
DARTON'S GIMEN POCKET DIRECT-VISION
SPECTROSCOPE IN CASE COMPLETE, 21/-. WILLIAM BAILEY & SON,
DARTON'S CHEMICAL SPECTROSCOPE in POLISHED HORSELEY FIELDS CHEMICAL WORKS,
Retort Stands, Bunsen's Burners, Gas Furnaces, and Chemica
Apparatus of all kinds Made and Repaired for the Trade. DR. LUNGE'S NITROMETER. This Apparatus, for the Determination of
F. DARTON & CO., I Nitrous and Nitric Acids, as described in Chemical News of 45, ST. JOHN STREET, .... nys, as described in Chemical News of 45, ST. JOHN STREET, WEST SMITHFIELD. E.C..
(ESTABLISHED 1834), . Estimation now ready. Particulars on application
Makers to the Science and Art Department, MAWSON and SWAN Newcastle-on-Tyne.
THE CHEMICAL NEW S. 16-inch chemical balance by Oertling: The exact length
Vol. XXXIX. No. 1001.
Estimation of Small Excesses of Weight. January 31, 1879.)
| The results given in this paper were obtained with a of the half beam (a) measured by a dividing engine is 20*2484 centimetres.
To find the Moment of Inertia MI% of the Beam.-The simplest way theoretically would appear to be this. Find the times of vibration ti tz and the deflections 0, 02 due to
the same excess þ with two differen: loads P, P2 in each ON THE
pan. Equating the values of p given for each by equation ESTIMATION OF SMALL EXCESSES OF WEIGHT | (4) we have BY THE BALANCE FROM THE TIME OF
Mglo +2Pjar Oztro
An equation which will give MgI: in terms of known
quantities. But on trial it was found that a very small By J. H. POYNTING, B.A., B.Sc.
proportional error in the observed time made a large error
in the value of Mgl”, and the following method, that While working last year on an experiment to determine
ron an experiment to determine | usually adopted in magnetic observations, was employed the mean density of the earth by the balance, I had to (in preference. A stirrup was suspended by a platinum measure such an exceedingly small difference of weight, 1 wire, and its time of vibration (ti) against the force of that I could not at that time estimate it by means of a torsion (u) of the wire was observed. The moment of rider, but was obliged to adopt the method described in inertia of the stirrup being S we havethis paper. Stated generally, it consists in treating the
tge="’S balance as a pendulum. Knowing the nature of the pendulum (that is its moment of inertia) and its time of vibra
fle tion, we can calculate what force acting at the end of one The time of vibration (ta) was then observed when a cylinarm of the beam will produce a given angular deflection. drical brass bar of known moment of inertia B was in. It is, in fact, an application to the common balance of the serted in the stirrup. We now havemethod which has always been used with the torsion
tzo=7*(S+B) balance when it has been necessary to calculate the forces measured in absolute measure. I cannot find any record of a previous application of the method, and as it might | The bar was then removed and the balance beam inserted be of use in very delicate weighings, or in verifying the | in its place, and the time of vibration (tz) givessmall weights in a laboratory, I have thought it worth while to give a full account of it.
tge=7*(S+MI) When small quantities of the second order are neglected, and the oscillations are of the first order, it will easily be From these three equations, eliminating S and 4 we found that the equation of motion of the beam of the obtainbalance is— (MI: +2Pa:ë+(2Ph+Mgk)e=ap... (1)
Now Bg was calculated from the weight and dimensions Where MI:=moment of inertia of beam about central
| of the bar to be 6332.83 (in centimetres and grammes
| The observed times were t; = 3.6792"; t2 = 4495" knife edge. M=mass of beam.
tz=7*1483". From these values we finda=half length of beam.
Mg =35656.* P=weight of either pan and the mass in it.
To Measure 0.--The angle of deflection was measured h-distance of line joining terminal knife edges below the by the number of divisions of the scale which the pointer central knife edge.
moved over. As the length of the pointer is 32.1006 centik=distance of centre of gravity of beam below central
metres, while 20 divisions of the scale measure 2.3658 knife edge.
centimetres, a tenth of a division, in terms of which the p=small excess in one pan.
deflection was measured, corresponds to an angle of O=angular defle&ion in circular measure produced by p. 0.0003996. The oscillations were observed from a distance g=gravity.
of 6 or 8 feet by a telescope. The resting-point (i.e., the
point where the balance would be in equilibrium) was found If Ö=0 we have the position of equilibrium given by—
in the usual way by observing the three successive extre
mities of two swings, and taking the mean of the second 0= Phi Mek .......... (2)
and the mean of the first and third. Five determinations The semi-periodic time is
of the resting-point were usually made with the excess
to be measured alternately added and removed. From MI: +2Pas
these five, three values of the deflection (n), due to the
excess, were calculated in a manner which will be seen ...cici (3) from the example below. V 2Ph+ Mgk
The Time of Vibration.—This was found from several From equations (2) and (3) we can eliminate 2Ph+ Mgk, determinations of the time of ten oscillations. The method obtaining
will be seen from the example. No correction was Mg19+2Pas
needed for the resistance of the air as long as the vibra. . . .. .. . P=#"
(4) tions did not exceed two divisions of the scale. When, agt
however, they were much more than that the time of vi. Prom this expression it appears that if we know the bration was found to increase with the arc. As the time moment of inertia of the beam, its length, and the weight of vibration frequently changes slightly, probably through at each end, we can find the excess ħ from the time of variations of temperature, it was usually observed before vibration and defle&ion.
* To this a small correction should be added if the adjusting bob is * Read before the Manchester Literary and Philosophical Society, not in its lowest position. This amounts to 7-6 for each turn of the December 10, 1878.
scrow, and may therefore in general be neglected.
Me_B(tz: -- tq:)
Apparatus for Production of Ferrous Salts for Titration.
and after the determination of the deflection (n), and the an angle of O'0003996 in circular measure formula (4), mean of the two taken as the true time.
| expressed in milligrms., becomes-
In our present example,
n=35.83 Pointer apparently Moving from Left to Right.
2Pa' = 24704
The length of time occupied in this determination was 16'25'5
18'33":5 127 not quite a quarter of an hour. .
The following table contains a series of results which I
have obtained of the weight of two centigramme riders, the Mean value of 10 vibrations
· 127 first of which was accidentally destroyed after the conclujih 15'49"
sion of the fourth determination. As the rider was always 17'56"
placed at division 5 on the beam, the values given in the
table are double those actually obtained :-
Weight of rider Mean Expt.
in milligrammes. Value. Mean value of 10 vibrations .. .. .. 126.75
145364 8.921 13.458 9978) Mean of means= 126875.
9.96 20'435 19*12 130355 13:10
10'47 DETERMINATION OF DeflectiON N.
11.44) Mean of pre
130355 1272 35-50 II'35 Extremities Resting- ceding and
130355 due to
120725 3583 II'45 of
35'5 11'20 m.grms. resting-points.
130355 12'903 36-37 109
19:406 22'08 Added
The apparatus usually employed to procure the absence Removed.. 55 67-25 1025 35625
of atmospheric air during the solution of metallic iron in acids consists of a flask fitted with a cork, through which is passed a tube bent twice at right angles. When in use
the free end of this tube is made to dip below the surface Added . ..
of water contained in a second flask or small beaker,
The chief defects of this arrangement are :
Ist. Want of portability.
2nd. Necessity for some form of support for tube. Time of VIBRATION at End.
Having recently had occasion to execute a considerable
number of determinations of metallic iron in samples of Pointer apparently Moving from Left to Right. steel and iron, I constructed an apparatus entirely free Observed time Observed time
from these defects, and very much more simple and con. No. of of passing of No. of of passage of Time of 10
venient to manipulate. The following is a description of tion. pointer through Vibratn. pointer through Vibrations. resting-point. resting-point.
the new arrangement, which will be readily understood by Ith 26'19" IO
the aid of the accompanying cut. 26'44":5 12 28'53"
A is a flask of 200 c.c. capacity ; B, a glass funnel 7 m.m.
diameter ; c, a glass tube of such a size as just to pass 27'35":5 16 29'44"
through stem of funnel B. D, an india-rubber joint con
neating B and c and forming a perfectly tight joint; E, an Mean value of to vibrations .. .. 128.25
india-rubber stopper, bored so as to pass stiffy upon c.
Perhaps a word upon the construction and use of the 26'32"-5 11 28'39" 126'5 apparatus may be admissible. Having selected a tube of 26'58" 13 29' 5"
127 the proper size, the upper bend is turned on so that the 27'23":5 15 29'30":5 127 point of the tube c, which should be narrowed to r5 m.m., 27'49" 17 2 9'56'':5 127'5
falls into the apex of B. Bis then placed in position and
secured by D; the stopper e is next fitted on c, and finally Mean value of io vibrations .... 127
the lower bend of c is turned on, taking care to allow so Mean of means=127.625.
much tube as will prevent e being injured by heat. ta=1207625.
* For this as for several other cases I removed the pans, and hung
the weights directly by finc wires from the suspended pieces. By this Rei
ering that one-tenth of a division of the scale is ' means the resistance of the air was very much diminished.