30

Chemical Notices from Foreign Sources.

(the shape of bowls, with small holes perforated in them);, then the felt cloth is put on the top, and the liquid is put on the filter and filtered through. The sediment at the top is used to colour pottery moulds; that which runs through is put in a tub, and 40 lbs of common salt added. Digest for six hours; then put on the filters again for four or five days. That which drains through runs away into the sewers; that on the top of the filters is the extract. For these proportions the extract should weigh 80 lbs. This is sour extract of indigo of commerce.

Free Extract. To make free extract of indigo, put 100 lbs. of the sour extract in a tub, 12 gallons of water as well. Neutralise the acid in the extract with strong sodaash liquor until it is free from any sour taste; then put on the filters for six days. It should weigh 100 lbs. when it comes off. That is free extract of indigo of commerce. -I am, &c.,

BRADFORD.

changed into earth by ebullition. In general, the error thus occasioned may be neglected; but this is not the case in alkalimetry, and in the use of boiling-flasks and beakers of Bohemian glass, now commonly employed on account of the ease with which they bear the application of heat. If it is required, for instance, to determine an alkaline carbonate in a liquid, we run into it drop by drop a standard acid until tincture of litmus added turns reddish, and to eliminate the carbonic acid which gives a vinous red to the litmus it is raised to a boil. Vessels of Bohemian glass, otherwise well adapted for this operation, after boiling for a few minutes only, give off alkali enough to restore the blue colour of litmus after saturation. The analysis is the more erroneous the longer the boiling is kept up. This, at least, is what results from the use of glasses brought from Germany, and sold at Nancy in 1873 and 1874This fact may be shown by boiling in a flask pure water mixed with tincture of red cabbage or syrup of violets slightly reddened by an acid. After boiling for a few minutes the liquid turns green. French glasses, with a base of soda, are not sensibly attacked, and therefore do

CHEMICAL NOTICES FROM FOREIGN not offer this inconvenience.

SOURCES.

lOTE. All degrees of temperature are Centigrade, unless otherw se expressed.

Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences, No. 24, December 14, 1874. Determination of the Speed of Light and of the

Solar Parallax.-M. A. Cornu.-The author finds the speed of light in a vacuum = 300400 kilometres per second of mean time, the probable error being below the onemillionth part.

Observations on the Reproduction of the Phylloxera of the Vine.-M. Balbiani.-A very lengthy paper; not adapted for abstraction.

The American Species of the Genus Phylloxera.— C. V. Riley.

Method Taken for the Discovery of the Substance most Efficacious for Combatting the Phylloxera at the Viticultural Station of Cognac.-M. Max Cornu. Experiments made upon Healthy Vines with Poisonous Substances.-M. Baudrimont.

Action of Hydrogen upon Nitrate of Silver.-M. N. Beketoff. The author concludes from a prolonged series of experiments that pure hydrogen reduces silver, like other metals, from neutral or faintly acid solutions. The negative results of M. Pellet may be explained either from the brief duration of his experiments, or from the too great acidity of his solutions.

Berichte der Deutschen Chemischen Gesellschaft zu Berlin,
No. 13, September 15, 1874.

On Maltose.-E. Schulze.-The author's experiments confirm the results of O'Sullivan's experiments, according to which maltose differs from grape-sugar, having the formula C12H22O11; reducing Fehling's liquid in a smaller duce as much suboxide of copper as 100 parts of maltose; proportion than grape-sugar, 65 to 66 parts of which reand having a much greater rotatory power (a=149'5° to 150.6°).

Formation of Asparagic Acid in the Pancreatic Digestion.-S. Radziejewski and E. Salkowski.-The authors find the formation of this acid fully demonstrated.

ganate of potash, and the action of ozone upon acetophenylic acid in an alkaline solution.

Oxidation of Ortho-Toluylic Acid to Phthalic Acid. W. Weith.-The oxidation was effected by means of a mixture of permanganate of potash and hydrate of soda. The yield of phthalic acid was from 85 to 90 per cent of the ortho-toluylic acid employed.

Electrolysis of Potassium - Phenylacetate. - T. Slawik.-An examination of the electrolysis of the neutral phenylacetate of potash, of the same salt in alkaline soluObservations on a Recent Communication by M. tion, of free aceto-phenylic acid, the oxidation of acetoVolpicelli on the Electric Influence.-M. E. Blavier.-phenylic acid in an alkaline solution by means of permanIn the Comptes Rendus for November 16 appears a note on electric influence, in which M. Volpicelli cites several experiments, the results of which appear to him opposed to the received theory. The author maintains that the facts in question are perfectly conformable to the theory as established by M. G. Green in 1828, and expounded in the "Theorie Mécanique de la Chaleur" of Briot. Two conductors, placed in connection by means of a metallic wire, assume the same potential or the same tension, and teositive fluid passes from the conductor whose potentiighest to the other. On the other hand, a conductored in the neighbourhood of a body positively fied takes a positive potential. If the latter is cond to an electrometer whose potential has been brought zero by a momentary communication with the earth, it ses a part of its positive fluid, which passes into the electrometer, and imparts to it a positive potential evinced by the separation of the movable leaves. This is the case of M. Volpicelli's second experiment.

Inconvenience Resulting from the Use of Vessels of Bohemian Glass in Chemical Analysis, and especially in Alkalimetry.-M. P. Truchot.-It is known that glass vessels in which various liquids, and even pure water, are boiled, give up by degrees a small quantity of their substance, silica, potash, soda, and lime. Lavoisier mentioned this reaction in showing that water is not

Structure of the Derivatives of Benzol.-E. Wroblevski.

Decomposition of Certain Diazo Compounds by Water.-E. Wroblevski.--Hypothetical papers.

Remarks on the Investigation of Hübner and Griess.-E. Wroblevski.-The author controverts the statement of Hübner and Griess that when a sulpho group is introduced into meta-brom-toluol one acid only is formed.

A Communication.-Rörsch and Fassbender.-The authors point out that a body resembling the alkaloids in its general behaviour with reagents may be developed from the liver in chemico-legal investigations. An experiment made with the recent liver of an ox yielded a body which, both in acid and alkaline solutions, was taken up by ether, and behaved like an alkaloid. Prof. Gunning, in investigating a case of poisoning by "liver-sausage" at Middleburg, obtained a similar body from a healthy boiled liver.

Remarks on M. Traube's Communication on the "Behaviour of Alcohol-Yeast in Media free from Oxygen Gas.-Oscar Brefeld.-In a paper read before the Chemical Society at Berlin, June 22, Traube maintains that "(1) Germs of yeast do not develope themselves in the absence of free oxygen, even in the most favourable media. (2) On the other hand, developed yeast, as Pasteur declares, can increase in suitable media, even in the absence of every trace of free oxygen." On this Brefeld remarks-As yeast germs and developed yeast are one and the same thing, namely, simple yeast cells; as, further, between development" and "increase" there is no primary physiological distinction, it follows that in his second proposition Traube contradicts what he has laid down in his first.

Constitution of Sulphurous Ethylic Ether.-A. Michaelis and G. Wagner.-- A hypothetical paper.

Constitution of "Chamber Crystals."-A. Michaelis and O. Schumann.-The authors remark that chamber crystals are generally regarded as the nitro compound of sulphuric acid, although this view is not based upon direct experiment. They find that chamber crystals, more correctly known as nitro-sulphonic acid, are mainly decomposed by perchloride of phosphorus in a manner accordant with this view, yielding the corresponding chloro-sulphonic acid.

Compounds of the Urethans with Aldehyds.-C. Bischoff. The compounds examined are those of cinnamic aldehyd and ethyl-urethan; salicylic acid and urethan; furfurol and urethan; aldehyd and propyl-urethan; oil of bitter almonds and propyl-urethan; and valeral and xanthogenamid.

Improved Apparatus for Fractional Distillation.— J. A. Le Bel and A. Henninger.-Not intelligible without the accompanying illustration.

Colouring Matters obtained from Aromatic Oxy Compounds and Nitrous Acid.-C. Liebermann.(Phenol Colouring Matter.) 5 grms. of phenol were mixed with an equal volume of concentrated sulphuric acid and well cooled, to prevent the formation of phenol-parasulphuric acid. The amount of the reagent required (sulphuric acid mixed with 5 per cent nitrite of potash) was 20 grms. This was added, with agitation, in such portions that the temperature rose permanently to 40° to 50° without becoming higher. The solution was at first brown, then a fine blue. The operation, with the quantities indicated, lasted fifteen minutes. At last there was a faint disengagement of gas. On cooling, the solution was poured with constant stirring into a large amount of cold water, filtered, concentrated in a porcelain vessel, and dried in the exsiccator. The substance thus treated can be dried at 130° without undergoing any change. It is a brown powder, readily soluble in alcohol. In alkalies it dissolves with a royal-blue colour. Its composition is C18H15NO3. (Orcin Colour.)-10 grms. orcin, 10 grms. sulphuric acid, 40 grms. of the reagent. The solution must become a fine purple red. When poured into an excess of water it yields a pure orange-red precipitate. The alkaline solution is purple with scarlet fluorescence. After washing for several days it is dissolved in alcohol, filtered, and evaporated. It forms a splendid cantharideslike mass. Other colouring matters are obtained at the same time,varying in solubility. (Thymol Colour.)-10 grms. thymol in fine powder, 10 grms. sulphuric acid, 40 grms. of the reagent. In this case the reagent must be added immediately after the mixture with sulphuric acid. The solution is first green, and then blue; the disengagement of gas must be avoided. The double volume of sulphuric acid is then added, and the whole allowed to stand for some hours. It is then precipitated by being poured into an excess of water, filtered, and washed perfectly. A violet resinous mass, soluble in alcohol, with a fine violetred colour.

Xylindein.-C. Liebermann.-Xylindein is a green colouring matter developed from decaying oak, beech, and birch-wood under the pathological influence of Peziza aruginosa. It contains

Action of Hydriodic Acid upon Santonic Acid, and on Meta-Santonin.-S. Cannizzaro and Amato.-MetaRemarks on Armstrong and Prevost's Communica-of water. It is not formed in the period of the first action santonin is formed from santonic acid by the elimination tion on the Behaviour of Nitrophenol Melting at 45° of hydriodic acid and phosphorus upon santonic acid, but with Bromine and Chlorine.-H. Hübner.-The author after the lapse of several days. considers that Messrs. Armstrong and Prevost have obtained in their experiments a mixture of ortho- and parabrom-phenol.

Certain Derivatives of Phenanthren.-E. Ostermayer. The compounds examined are bromised phenanthrenchinon; dibrom-diphenic acid, C14H8, Br2O4; and diphenic ethyl-ether.

New Formation of Phthalic Acid.-W. Weith and R. Bindschedler.-In preparing anthrachinon-sulphuric acid, a large quantity of a body was obtained, which sublimed in large colourless needles, and dissolved in boiling water, from which it separated out in shining scales. It proved to be phthalic acid.

On Acenaphthylen.--M. Blumenthal.-The author has Nitrile and Amide of "Hydroxyl-Caprylic Acid," examined acenaphthylen-bromide and its derivatives. and the Amide of Amido-Caprylic Acid.-E. ErlenPreparation of Stilben and Certain of its Com-mayer and O. Sigel.-The nitrile in question is a colourless pounds.-F. C. Lorenz.-Large quantities of stilben were dissolves in it very sparingly. It is readily soluble in oily fluid of peculiar odour, which floats upon water, and passed slowly-one drop in ten seconds-over oxide of alcohol and ether. With fuming hydrochloric acid it forms jead at a dark red-heat in an iron tube. The distillate a clear liquid, which, on cooling, congeals to a paste of was partly solid, partly liquid. The former portion consisted chiefly of stilben. The latter portion was stilben white, silky, crystalline leaflets. This is the amide. along with other hydrocarbons dissolved in unchanged toluol. On distilling off the toluol there remained a semisolid body, which, when united to the solid distillate, amounted to 18 per cent of the toluol employed. It was obtained perfectly pure by re-crystallisation from alcohol. The accompanying hydrocarbons were diphenyl, phenanthren, anthracen, and certain liquid bodies. Benzyltoluol and naphthalin were not detected.

True Leucic Acid Nitrile, and on the Leucic Acid therein Contained.-E. Erlenmayer and O. Sigel.-The true nitrile, differing essentially from that described by Bopp, is a colourless oil, which floats upon water without dissolving. With ether and alcohol it is miscible in every proportion. At the heat of the water-bath it suffers no change, but at higher temperatures it splits up into hydrocyanic acid and amylic aldehyd.

On Mesitylen.-A. Ladenburg.-Not adapted for ab- TUESDAY,

Schiff. The author in testing the results of Brackebusch WEDNESDAY, (vii., p. 225) obtained merely negative results.

Synthesis of Aromatic Acids.-V. von Richter.- THURSDAY, 21st.-Royal, 8.30.

choienck, Poland.-F. Wreden and A. Fuchs.-A de- FRIDAY, 22nd.-Royal Institution, 8. Weekly Evening Lecture. Sir tailed statement of results.

Compound of Sarkosin and Guanidin.-E. Baumann. If sarkosin is heated with hydrochlorate of

guanidin there is obtained a clear fused mass, which SATURDAY, dissolves in hot alcohol, and forms fine tabular crystals.

mass on which radiation falls, with the relation of its

NEWS. mass to its surface, and with the temperature of the

apparatus (62, 63, 64, 65, 67, 75). The temperature of the body used to attract or repel the brass or pith ball also affects the critical point, but it cannot, I think, modify it much; for with the apparatus last described no difference in kind of movement, but only in degree, was noticed, whether the spiral were ignited to full redness, or whether it were merely warmed by a momentary contact of the wires. Further experiments are in progress which may throw light on this point.

49. The very high amount of rarefaction needed before this neutral point is reached, and the change of direction of movement on applying a hot body to one arm of the balance, caused by a difference of exhaustion of a few millimetres on one side or the other of the point of neutrality, are, I think, a sufficient explanation of the anomalous results which were met with in my earlier experiments (2, 19, 20, 21, 22).

50. Although these results were sufficient to show that air-currents could not be the cause of the movements of the balance, I was anxious to decide this point once for all, by a form of experiment which, whilst it would settle the question indisputably, would be likely at the same time to afford information of much interest. Having found that the balance last experimented with had its neutral point close FIG, 4D.

34

Attraction and Repulsion Resulting from Radiation.

time pretty briskly, to prevent air diffusing in. The joints were made of double caoutchouc tubing, the smaller one tightly wired on and coated with glycerine before the larger tube was slipped over it. The whole was then tightly bound with wire. To prevent air creeping down between the mercury and the glass, glycerine was poured over all the mercury joints, except the one at the top of the mercury fall-tube, which was kept for oil of vitriol, with which the pump was lubricated from time to time. 52. The apparatus being exhausted of air, the balance was adjusted by heating the ends so as to slightly char the one which happened to be the lower. ƒ and g are two collars of silver foil encircling the tube where the

{CHEMICAL NEWS,

January 22, 1875.

the gas collected at the bottom of the mercury fall-tube of the pump was entirely absorbed by potash. When this was found to be the case, the exhaustion was allowed to proceed to the highest possible point. The pump was then stopped; an induction-current now being passed between the wires at the end b showed the usual white light of a carbonic-acid vacuum (a trace of red shows atmospheric nitrogen).

The sticks of potash in the copper boat in c were then heated to incipient fusion, and the whole was allowed to cool for some hours. The tube was then sealed off by applying a spirit-flame to the contracted part a; the potash was then heated again, and the whole was set FIG. 5.

heat is to be applied, and connected with earth by wire. At a very high rarefaction the flame of a spirit-lamp excites so much electrical disturbance in the balance that its adjustment becomes well nigh impossible. This arrangement was adopted in the endeavour to carry off the electricity; it is, however, only partially successful, and the electrification of the balance at the highest rarefactions is still very troublesome.

The air having been removed from the apparatus as perfectly as the Sprengel pump would effect it, carbonic acid was let into the tube by cautiously opening the tap h. Exhaustion was again effected, and carbonic acid passed in a second time. This was then pumped out, and the apparatus was filled a third time, This alternate filling with carbonic acid and exhaustion was continued until

C

aside to give the potash time to absorb the residual carbonic acid.

53. By testing from time to time with an induction-coil, the progress of the absorption could be traced; and when the current ceased to pass through the tube, but preferred to strike across in air the full length of the spark, the vacuum was considered nearly perfect. Warming the potash with a spirit-flame, at any time, will cause it to give off sufficient aqueous vapour to allow the spark to pass as a cloud-like luminosity. This will be gradually

* When the pump is working in a very good vacuum, the friction of the falling mercury produces a very beautiful effect in the dark. Brilliant points of light flash about wherever the mercury-drops are splashed from side to side, and the pump is frequently illuminated with a phosphorescent glow filling all the tubes.