2

ཏུ

8

CH3

CH3>C

OMgCl
CH3 CHCI-CO2C2H5.

With water and acetic acid the solution yields a-chlor-8oxyisovalerianic ether of formula

CH3 3>C(OH)—CHCI - CO2C2H5.
CH3

From this ether, dimethyl glycidic ether can be obtained by treatment with the theoretical amount of sodium ethylate. This last reaction is important because it is general and enables a large number of glycidic ethers to be prepared, starting with an a-3-ethylenic acid.

Constitution of Vicianose and Vicianine -Gabriel Bertrand and G. Weisweiller. From the results of the oxidation of vicianose it appears that the glucose and arabinose entering into its composition are united by the aldehydic function of the pentose, and if it is assumed that the mode of linking is oxidic (as is most probably the case) the composition of the new saccharide can be represented by the formula

CH2OH-(CH.OH)2-CH-CH-O-CH2

No. 22, November 28, 1910.

Amines.-Frédéric Reverdin and Armand de Luc.-DiNitration of Mono- and Di-acetylated Aromatic acetylated derivatives are nitrated only at a higher temperature than that necessary for the nitration of the monoacetylated derivatives. The presence of two acetyl groups in the molecule of p-toluidine diminishes the stability of the compound.

Glucodeconic Acids.-L. H. Philippe.-The author method, and also 3-deconic lactone from which the acid has synthesised a-deconic amide, C10H21OION, by the usual anhydride,—

CH2OH-(CH.OH)8-CO-O-CO-(CH.OH)8-CH2OH, can be obtained by concentrating the solution.

MEETINGS FOR THE WEEK.

TUESDAY, 17th.-Royal Institution, 3. "Heredity," by Prof. F. W.
Mott, F.R.S., &c.
WEDNESDAY, 18th.-Royal Society of Arts, 8. "The Dutch Labour
Colonies" by J. C. Medd.
Microscopical, 8.

Annual Address of the President, Prof. J. Arthur Thomson, M.A. THURSDAY, 19th.-Royal Society of Arts, 4.30. "Banking in India," by Reginald Murray. Chemical, 8.30.

"Intramolecular Rearrangement of Diphenylmethane o-Sulphoxide," by T. P. Hilditch and S. Smiles. "Reactions between Chemical Compounds and Living Muscle Proteins," by V. H. Veley. "Interaction of Alloxan and Glycine," by W. H. Hurtley and W. O. Wootton. "Decomposition Products of Tetramethylammonium Nitrite under the Action of Heat," by P C. Rây and H. K. Sen. "Retardation and Acceleration in the Dissolution of Mercury in Nitric Acid in presence of Minute Quantities of Ferric Salts and Manganese Nitrate," by P. C. Rây. "On dl- and d-A-m-Menthenol(8) and dl- and d-A2: 8 (9)-m-Menthadiene," by W. N. Haworth, w. H. Perkin, and O. Wallach. "Identity of Xanthaline with Papaveraldine," by Miss B. Dobson and W. H. Perkin. "Amalgams containing Silver and Tin," by R. A. Joyner. Studies of the Constitution of Soap in Solutionthe Electrical Conductivity of Sodium Stearate Solutions," by R. C. Bowden. "Additive Compounds of Phenols and Phenolic Ethers with Polynitro-aromatic Derivatives," by J. 1. Sudborough and S. H. Beard. "Effect of Contiguous Unsaturated Groups upon Optical ActivityPart VI., Influence of the Carbonyl Group upon Optical Rotatory Power-Part VII., Relative Influences of Aromatic and Hydroaromatic Nuclei upon Optical Rotatory Power-Part VIII., Influence upon Optical Activity of Two Contiguous Unsaturated Groups in Comparison with that of One Unsaturated Group at varying Distances from the Optically Active Complex" and "The Relative Effects of Ethylenic and Acetylenic Linkings upon Optical Rotatory Power," by T. P. Hilditch. "Direct Action of Radium on Ammonia," by E. P. Perman. "Cupritartrates and Analogous Compounds," by S. U. Pickering. Royal Society. "Action of B. lactic acrogenes on Glucose and Mannitol," by G. S. Walpole. "The Pharmacological Action of South African Boxwood (Gonioma Kamassi)," by Dr. W. E. Dixon. "Autoagglutination of Red Blood Cells in Trypanosomiasis," by Dr. W. Yorke. "Transformation of Proteids into Fats during the Ripening of Cheese," by M. Nierenstein. "The Action of X-rays on the Developing Chick," by J. F. Gaskell. Royal Institution, 3. "Recent Progress in Astronomy," by F. W. Dyson, Astronomer Royal. "Chemical and Physical Change

CHEMICAL NEWS,}

Jan. 20,

THE CHEMICAL NEWS.

VOL. CIII., No. 2669.

NOTE ON THE TEMPERATURE SCALE
BETWEEN 100° AND 500° C.*

By C. W. WAIDNER and G. K. BURGESS.

Ar the present time the standard scale of temperatures in
the interval o° to 100° C. is that defined in a resolution of
the International Committee on Weights and Measures,
namely, that of the constant volume hydrogen thermo-
meter (1). Above 100° temperature measurements have
been made with air, hydrogen, and nitrogen thermo-
meters, and in recent years there seems to be a preference
to work with the constant volume nitrogen thermometer.
In a previous paper (2) the authors determined the
melting- and freezing-points of a number of metals on the
temperature scale defined by the platinum resistance
thermometer calibrated in ice, steam, and sulphur vapour
(444 70° on the constant volume nitrogen thermometer).
In order to throw further light on the probable accuracy of
the temperature scale so defined, in the interval 100 to
500° C., the authors have made some further measurements
by the same method on the boiling-points of naphthaline and
benzophenone, which temperatures have been determined
by a number of observers using both platinum and gas
Four thermometers were used, made of different sizes of
pure platinum wire from Heraeus, and from Johnson,
Matthey, and Co., and having fundamental intervals
ranging from I'I to 10'6 ohms. Three of these thermo-
meters were used both as Siemens three-lead com-
pensated, and as four-lead potential terminal thermo-
meters. The apparatus and methods are fully described
in the previous paper.

thermometers.

The boiling points were determined with the sulphur-
boiling apparatus, using glass tubes about 4'5 cm. diameter
and 45 cm. long, furnished with a side condenser tube with
inlet near the top, and the thermometer was shielded by
an aluminium cone in exactly the same way as in sulphur.
With this shield omitted, the thermometer readings were
about o'08° low in naphthaline and 0.35° low in benzo-
phenone. Raising the thermometer 6 cm. produced a
lowering in temperature of less than 0.02°.

Besides the boiling-point determinations, a few measure-
ments were also taken of the freezing-points of tin,
cadmium, and zinc to compare with the previous work.
The results are given in Tables I. and II. It will be seen
that the freezing-points newly determined are practically
identical with those previously found by the authors,
showing that the temperature scale of the present work
is in agreement with that of the previous investigation.
The reduction of the boiling-points to normal pressure
was made by means of formulæ satisfying the data both of
Crafts and of Jaquerod and Wassmer.

25

In Table III. are collected the determinations of the

by the various observers, and where possible the values
boiling-points of naphthaline and benzophenone as made

have been reduced to the same basis, namely, to a scale on
which the sulphur boiling-point is 444 70°.

It will be seen that, with the exception of the determina-
tions of Jaquerod and Wassmer, there is a close agree-
ment. Their results may be low, owing to the fact that
the condenser of their boiling apparatus was immediately
above the gas thermometer bulb, which was not screened
in any way against the cooling effects of condensation and
radiation. It should also be noted that the volume of
their gas thermometer bulb was only 66 cc., which is small
for work of precision. Their results may be indirectly
tested by assuming either of their boiling-points as the third
standardisation temperature of a platinum thermometer,
and using the therometer so calibrated to determine the
sulphur boiling point. This procedure would give S
b.p. = 443 ̊0°, a value 15° lower than any determination,
and for the constant & of the platinum thermometer 1.40
instead of the usual 150 as found when S b.p. 444'7 is
used as the third standardisation temperature.

=

In view of the very general use of the S b.p. for the
standardisation of platinum thermometers, we have sum-
marised in Table IV. the results of the more important
determinations of this temperature, and reduced them to
the same basis, namely, that of the nitrogen constant
volume thermometer under a pressure of 1 metre of Hg
at o° C. The temperatures thus observed are obtained
only under very definite experimental conditions, which are
described at length in the previous paper and elsewhere.
tion (15) with a nitrogen constant volume thermometer at
Messrs. Day and Sosman in a recent elaborate investiga-
high temperatures (400° to 1550° C.) have determined the
freezing points of a number of metals, among them zinc
and cadmium, by transferring from the gas scale with
thermo-couples. They find for the freezing-point of zinc
418-20, and for cadmium 3200°, whereas the platinum
resistance thermometer calibrated in ice, steam, and sulphur
vapour (444°70°) gives 419-4° and 3210° for zinc and
cadmium respectively, with a precision of o'05° C. The
explanation of this difference is of great importance in
accurately fixing the gas scale in the interval 100° to
500° C. If the freezing-point of pure zinc is 418.2°,
instead of 419.4°, then it would follow that the boiling.
point of sulphur must be 443'5° instead of 444'7°, as found
by a number of observers as shown (see Table IV.).

It should also be noted that the gas thermometer as
used by Day and Sosman was adapted primarily to give
the highest attainable accuracy for the higher range of
temperatures-that is, above 1000° C., and that no
measurements with the gas thermometer itself were made
below 400°, nor did they consider their thermometer of
sufficient sensitiveness in the lower temperature ranges
to warrant a determination of its fundamental interval,
0-100° C.

Some further evidence on the accuracy of the gas scale
that is defined by a platinum resistance thermometer
calibrated in ice, steam, and sulphur (444 70°) is afforded
by the comparison by Holborn and Henning of two
platinum thermometers with a nitrogen thermometer in the
interval 150° to 200° C. This work shows that the two
scales so defined are in agreement to within a few
hundredths of a degree. If the value usually assigned to the
S b.p. (444 70°) were over 1° high, then the scale defined
by the platinum thermometer at 200° might be expected to
be about o 2o high, whereas these observers find an extra-
ordinarily close agreement between these two scales. It
is also of interest to note that these observers give evidence
that their gas thermometer agrees with Regnault's gas
scale to within o‘02° up to 230° C.

In view of the doubt, however, which is thrown on the
present generally accepted value of the S b.p. by the work
of Day and Sosman, new determinations of this point

1910.

References will be found at the end of the paper

designed for work in this range are much to be desired.

11. Chappuis and Harker, "On a Comparison of Platinum and Gas Thermometers," Phil. Trans., 1900, A, cxciv., 37.

12. Holborn," Untersuchungen uber Platinwiederstände und Petroläther Thermometer," Ann. Phys., 1901, vi., 242. 13. Rothe,

Bestimmung des Schwefelsiedepunkts," Zeit. f. Instrumentenkunde, 1903, xxiii., 364. 14. Eumorfopoulos, "The Boiling-point of Sulphur on the Constant Pressure Air Thermometer," Proc. Roy. Soc., 1908, lxxxi., 339. Callendar," Note on the Boiling-point of Sulphur," Proc. Roy. Soc., 1908, lxxxi., 363. Callendar, "The Boiling-point of Sulphur Corrected by Reference to New Observations on the Absolute Expansion of Mercury," Proc. Rov. Soc., 1909, lxxxiii., 103.

15. Day and Sosman, "The Nitrogen Thermometer from Zinc to Palladium," Am. Journ. Sci., 1910, xxix., pp. 93-161.

THE fact that practically nothing has been published on the above subject, and the remembrance of the many long hours spent in digging out these methods and adapting them to enamels and enamel raw materials, has led the author to put them in this form for others who might use them. While he claims little originality in the methods themselves, he does claim originality in the adaptations here given. Each and every one of these methods has been thoroughly tried out, either in the laboratory of the Columbian Enamelling and Stamping Co., at Terre Haute, Ind., or in the chemical laboratories of the University of

Kansas.

The analysis of an enamel presents one of the most difficult and complicated problems with which the analyst comes in contact. An enamel is generally an insoluble silicate containing besides silica, iron, alumina, calcium, magnesium, and the alkalis, generally boron, fluorine, manganese, cobalt, antimony, and tin, and sometimes phosphorus and lead. Before attempting the quantitative analysis of any enamel a thorough qualitative analysis should be run, and this will enable one to choose a quantitative separation. One of the most important aids to a correct analysis is a thorough grinding. The sample should be ground to an almost impalpable powder, and every conceivable precaution for accuracy taken.

The analysis of a sample of enamel to be taken from a piece of ware involves an extra difficulty. The coating of enamel almost always consists of two or more layers--the lower a large ground coat, and the upper ones white or coloured enamels. For an illuminating analysis these must be separated. The author has found the following method of V. de Luyeres good for doing this (Comptes Rendus, viii., 480):-The surface is scratched lightly with a piece of emery cloth or a file, and a coating of gum acacia or glue is applied. The vessel is placed in an airbath and heated. The glue on hardening generally carries with it some of the outer coat. The glue or gum is then broken off, dissolved in water, and the enamel pieces collected on a filter-paper. Some obstinate enamels require painstaking methods, such as chipping off with a chisel and separating the different coats-which always vary somewhat in colour-by picking out and sorting, using a pair of forceps. A large reading-glass will be useful in making these separations. Any iron from the vessel which may adhere to the enamel may be removed by means of a magnet after the sample is ground.

* From a Paper read at the Pittsburg meeting of the American Ceramic Society, February, 1910. From the Chemical Engineer, xii., No. 5.

Analysis of an Enamel containing Fluorine.

In an enamel containing fluorine the usual methods for silicates cannot be used, as silicon-tetrafluoride would be volatilised in the evaporation with hydrochloric acid for the separation of the silica.

Fluorine.-One grm. sample is very finely ground, slowly fused with 2 grms. each of potassium carbonate and sodium carbonate. The melt should be kept in quiet fusion over as low a flame as possible for one hour. The melt is transferred (after cooling quickly by giving the crucible a gyratory motion while held in the tongs, causing the melt to cling to the sides instead of forming a solid cake in the bottom) to a platinum dish, where it is covered with a watch-glass, and boiled vigorously with 100 cc. of water. The residue is filtered off, and is saved for the determina tion of the metallic oxides and the silica.

The covered solution is digested on a steam-bath for an hour with several grms. of ammonium carbonate, and on cooling more carbonate is added, and the solution is allowed to stand for twelve hours. The precipitate of silica, alumina, &c., is filtered off, washed with ammonium carbonate water, and is saved for further determinations.

The solution. containing all the fluorine and traces of silica, phosphate, &c., is evaporated until gummy, then diluted with water and neutralised as follows:-Phenolphthalein is added, and nitric acid (double normal) drop by drop until solution is colourless.

The solution is boiled, and the red colour which reappears is again discharged with nitric acid, boiled again, and neutralised again until I cc. of acid will discharge the colour.

The last traces of silica, &c., are now removed, as recommended by F. Seemann (Zeit. Anal. Chem., xliv., 343, by the addition of 20 cc. of Schaffgotsch solution. This solution is made as follows:-250 grms. of ammonium carbonate are dissolved in 180 cc. of ammonia (0.92 sp. gr.) and the solution is made up to 1 litre). To the cold solution 20 grms. of freshly precipitated mercuric oxide are added, and the solution is vigorously shaken until the mercuric oxide is dissolved.

The precipitate caused by the Schaffgotsch solution is filtered off and saved, and the solution is evaporated to dryness and the residue taken up with water.

Any phosphorus from the bone ash used in some enamels, and chromium which may be present, are removed from this alkaline solution by adding silver nitrate in excess. Phosphate, chromate, and carbonate of silver are here thrown down, and may be determined again if desired.

The excess of silver is removed from the solution by sodium chloride, and I cc. double normal sodium carbonate solution is added to the filtrate, and the fluorine is precipitated by boiling with a large excess of calciumchloride solution.

The precipitate, consisting or a mixture of calcium carbonate and fluoride, is collected on a blue ribbon filterpaper and is washed, dried, ignited at low red-heat, separated from the filter-paper, and the residue with the ash of the paper is treated with dilute acetic acid until carbon dioxide is no longer given off on heating. The liquid is then evaporated to dryness, the residue taken up with hot water (slightly acidified with acetic acid), filtered, dried, and gently ignited and weighed as CaF2. This may be checked by heating with sulphuric acid, driving off all the excess of acid and re-weighing as CaSO4. This method gives results for the amount of fluorine, checking within 0.2 per cent, but which are generally from 2 per cent to 4 per cent low.

Silica. For the estimation of silica and the metallic

oxides, first the precipitate from the Schaffgotsch mercuric oxide solution is ignited to drive off the mercuric oxide, and the silica left is weighed. The residue from the original melt, together with the precipitate obtained by ammonium carbonate (after the drying and removal from the filter-paper, whose ash is added) are then dissolved in hydrochloric acid. The solution is evaporated to dryness