212

(To be continued.)

CHEMICAL NEWS, Nov. 17, 1876.

a large platinum dish over the flame of a treadle blowpipe in the Royal Artillery Institution laboratory, I repeated the experiment with an ounce of pure crystalline boric acid. The platinum dish was cleaned with boiling nitric acid, and subsequently with charcoal powder and distilled water. The fused boric acid seemed beautifully white and pure, but, proceeding to test with it pyrologically, I found it became opaque on cooling, and therefore was utterly useless for the purpose.

(7.) I then became convinced that the apparent waste of my time and boric acid was in reality an immense gain of fact, in furtherance of the conclusion I had so long entertained. Confirming the phenomenon with a new platinum spoon filled with pure crystallised boric acid before the blowpipe, it was impossible to avoid the conclusion that these bulks of platinum, respectively heatable only to redness by the different means employed, had not ceased during the operation to emit the orange (or D-lines) flame, which, absorbed by the boric acid in each case, had rendered it opaque on cooling, and useless for pyrological

purposes.

(8.) This hypothesis was confirmed in the following manner:-A roll of new platinum foil, similar to (4),

(1.) IN 1871, at Mussoorie, India, a friend, Mr. Hennessey, of the Indian Trigonometrical Survey, since elected Fellow of the Royal Society, invited me to inspect the then novel "atmospheric lines" of the solar spectrum, through the large spectroscope lent him by the Royal Society, from the top of a mountain peak.

(2.) From a priori considerations, unnecessary to enter into here, I at that time suspected that the "D" absorp tion lines of the solar spectrum are water lines, and not due to sodium; and I communicated my supposition to

Mr. Hennessey, who rapidly appreciated the importance

of the deductions possible from such a standpoint.

(3.) In the year above mentioned I found that emission of the so-called sodium flame, afforded by platinum before the blowpipe, was wholly dependent on keeping the platinum at a red (not white) heat; so that the same wire, incandescent, and affording a continuous spectrum at the point of the blue pyrocone, immediately produced an orange (or "D"-lines) tinge again when moved to a cooler part, about a quarter of an inch inside the point, and a reddish or rose tint when shifted to the extreme base of the pyrocone.

(4.) I then confirmed this observation by heating a considerable quantity of new clean platinum foil (compactly rolled together by clean steel forceps), which, I ascertained, could not be incandescently heated by the mouth blowpipe, and which therefore never ceased emitting the orange flame.

(5.) Conclusion from these Experiments. It is obvious, here, that if this orange flame (exhibiting spectroscopically only D-lines) be due to sodium, that metal must be in some mysterious manner (a) proportional to the bulk of the platinum used, and (b) eliminable from the blowpipe flame according to the particular part of the pyrocone touched by the platinum. The logical conclusion, according to the sodium hypothesis, therefore, seems that sodium exists both in pure platinum and in the blue pyrocone produced by the blowpipe, but that that, in a certain state of heat, is required to eliminate it from this, and that this must be only partially employed to develop

it in that.

trical pen along with another wire (b), containing a bead of pure, transparent, fused boric acid, in such a manner that the point of the blowpipe pyrocone, heating (a) to redness, caused the orange (D-lines) flame to impinge upon (b), which, after a short exposure to this treatment, became opalescent on cooling.

(against the hypothesis of sodium being the cause of the (9.) All now required to complete the negative evidence D-lines flame) was a proof of the converse of (8), viz., that an undoubted sodium flame will not and cannot produce opalescence in a bead of pure fused boric acid. Knowing flame from a bead of sodium carbonate to impinge upon this to be the case, I went further, and caused the orange the opalescent bead (8) from a considerable distance in disappeared, and the bead was perfectly clear on cooling. the geometrical pen. After a few seconds the opalescence

A bail of cobalt oxide floating in the bead, previously unaffected by the opalescence of (8), was now partially dissolved, giving the whole bead a pink tinge.

(10.) Conclusions from Experiments (8) and (9).—The argument generally adopted by the defenders of the sodium hypothesis of the D-lines flame is that the quantity of sodium thus alleged to be indicated by the spectroscope is too minute to be detected by any other means, but we have here incontrovertible evidence (a) that the reaction afforded by the orange flame emitted from platinum in pure fused boric acid is an exceedingly strong one, and (b) that it is exactly the opposite of that afforded by an undoubted sodium flame. Secondly, to believe that this flame is due to sodium involves the mathematical absurdity of supposing that sodium in combustion can, at one and the same time, impart opalescence to boric acid, and also remove opalescence from boric acid. It is therefore impossible to is due to sodium; and if this flame (exhibiting only Dbelieve that the orange flame emitted by red-hot platinum lines in the spectroscope) is not due to sodium in one case it cannot be due to that metal in any.

(11.) If this evidence be admitted, as it apparently must, to be absolutely incontrovertible, I will undertake to prove (in another paper) that the D-lines spectral flame is in reality produced by water, in the peculiar combined condition found in hydrates, which I have termed " chemical water," and which Dr. F. Guthrie, advancing by other methods of analysis, has termed "solid water."

Destruction of the Vineyards of the Côte d'Or.M. E. du Mesnil.-The vines of this important district are gradually perishing, though neither in the leaves nor the roots have the most skilful observers been able to find any indications of the phylloxera. The author thinks that some new enemy has made its appearance.-Comptes Rendus.

214

These results may be classified as follows :First. The amount of acid dissolved by the water from the oils seems to bear no relation to the amounts of copper dissolved by the oils. In some cases the acidity is large and the amount of copper found in solution small or absent, and in others the acidity is small and the amount of copper found in solution large.

Second. As a rule, when the amount of copper dissolved by the oil is large the amount extracted by water is also large, but in a few cases this does not seem to be so.

Third. Some oils produced on the surface of the copper slip a complete coating of a green salt of copper of a greater or less degree of thickness, and it is remarkable that those oils which have this action have not in any case dissolved more than a trace or small quantity of the copper, and in some cases no copper in solution was found. The following is a list of the oils which have this p'culiar action in the first and second series respectively:Series I.

Series II.

Palm nut oil.

Ground nut oil.

American tallow oil. Common tallow oil. Lard oil.

Some oils fall partly under this classification inasmuch as they are not completely covered with the green deposit but are not entirely free from it. In the first series two oils have covered some parts of the copper plate with a blackish deposit and other parts with a green deposit, viz., One of the samples of cotton-seed oil and lard oil.

In the second series, where the copper slips stood in the

Absent.

Very large.

Large.

Rather large.

Absent.

Absent. Absent.

oils only partly immersed, two samples have produced green deposits only at the point where the slips came in contact with the immediate surface of the oil. These were pale rape-seed oil and brown rape-seed oil, and one where the line of green deposit at the surface was exceedingly narrow and very slight, viz., American sperm oil; lastly, one sample covered the surface of the copper slip with a network of green deposit, viz., North American neatsfoot oil.

It is most remarkable that no samples of fish oil, with oil, produced any deposit of green salt of copper on the the very slight exception above named of American sperm metallic slips; the surfaces of the copper placed in each of the thirteen different samples used in both series having been preserved in a perfectly bright condition.

Fourth. As a rule those oils which dissolved large pro portions of copper, left the surfaces of the copper slips in as bright, or almost as bright, a condition as when they were first introduced. Of the oils belonging to this class may be mentioned:

For Series II., as only three fish oils were employed, only whale oil remains to be placed in this class, although strictly speaking it does not belong to it, as it had not dissolved even a trace of copper. This sample of oil solidified from the surface by oxidation into about one-third the depth of the oil. The oil underneath was quite fluid. Fifth. The slips of copper in contact with some of the samples were stained more or less with a dark-coloured deposit. The following is a list of those having this peculiar action:

Lastly. The three samples of mineral oils in both series produced on the copper slips a peculiar characteristic deposit, of a greyish colour.

Many of the samples in the first series dissolved only a trace or very small quantity of copper, but only two were absolutely free from even a trace of that metal, viz., English neatsfoot oil and tallow oil. In the second series five samples came under this class, viz., one sample of olive oil, palm nut oil, American tallow oil, common tallow oil, and of whale oil which was protected from the air by a thick coating of oxidised oil on its surface. With the view to further examine the green copper salt incrustation which had been produced on the slips of copper in some of the oils, I took the slip which had been left in contact with No. 1 olive oil of the second series, which was covered thickly by the incrustation, and from which it hung in flakes: this was carefully scraped off, and part of the excess of oil absorbed by blotting-paper. The incrustation was then transferred to a test-tube, and washed by decantation with petroleum spirit: this dissolved the excess of olive oil, together with a copper salt which coloured the petroleum spirit of a deep blue-green colour on its first treatment. The incrustation was washed so long as the spirit continued to dissolve any copper; the petroleum spirit solution was then filtered, and the filtrate evaporated on a water-bath, to drive off all the spirit. The residue-which consisted of the excess of olive oil, together with the soluble copper salt-was set aside to cool, and in the morning the copper salt was found to have crystallised out in beautiful green feathery crystals.

Ferrocyanide of potassium, added to and shaken with the petroleum spirit solution of the soluble copper salt, at once decolourised the liquor, and threw down all the copper on the ferrocyanide.

The insoluble copper salt, or part of the incrustation, was then submitted to examination. It is a deep green solid, lighter than water, and insoluble in that medium. Part of this salt was placed in a test-tube, and water added, which was gradually heated till about 200° F., when the solid melted to a deep green oily liquid, which floated on its surface. It is insoluble in alcohol, slightly soluble in bisulphide of carbon and in ether, and is decomposed when heated with most of the acids.

Some of the salt was heated in a test-tube with very weak hydrochloric acid, the copper was separated and dissolved in the water solution of acid, whilst a clear, transparent, oily liquid floated on the surface, which when cold solidified to a white compact solid, resembling in appearance bees'-wax, It, however, differs from this and the well-known solid fatty acids by the peculiar way in which it crystallised when placed on a warmed microscopeslide and allowed to cool gradually. When viewed through

21

the microscope by means of polarised light, it crystallises in beautiful small star-like groups of crystals, which have the power of polarising light. This white body is difficultly soluble in alcohol in the cold, but dissolves with facility in hot alcohol. It is easily soluble in ether. I intend to continue my enquiry into the properties and composition of these bodies.

Chlorine, Bromine, Iodine, and Fluorine.
By Dr. E. MYLIUS, of Ludwigshafen.

As regards recently discovered sources of iodine we have
already mentioned the mother-liquor of Chilian nitre.
No others of importance have been discovered. Leuchst
indeed points out that the flue dust of blast-furnaces con-
tains compounds of iodine along with other soluble salts.
Thus from the dust of the Rosenberg furnace, near Sulz-
berg, he obtained 0034 per 1000; from the Komoran
furnace, near Herzowitz, o'042; and from that at Kreutz-
thale, o 146, and calculated that 35 lbs. iodine could be
annually prepared at the first-mentioned furnace. But
even in the improbable event that the iodine thus oc-
curring could be extracted at a remunerative cost the
total production would still be quite insignificant.
As for the total production of iodine there exist few
numerical statements from which it can be ascertained.
By far the greatest quantity is obtained in England and
France. In the year 1871 the quantity produced in Great
Britain reached 114,799 lbs., 9-10ths of which came from
Glasgow. One of the works there (W. Paterson) in the
year 1867 alone produced 112,000 lbs. In France the
production in 1867 was 55,600 kilos.; therefore rather
less than in England.

In 1868, 40 kilos. were daily prepared at Tarapaca from Chilian nitre (Balard) corresponding to a yearly production of 290 to 300 cwts. This quantity, however, must be considerably reduced if we remember that Sticht|| found only 50 per cent of real iodine in a Chilian sample.

The method of extracting iodine is essentially unchanged notwithstanding many proposed improvements. In the Report of the London Exhibition of 1862, A. W. Hofmann describes the process of Stanford which was then taken up with great zeal, and for which a medal was awarded by the jury. Its principle is the preliminary distillation of the seaweed, and the utilisation both of the volatile products and of the residual charcoal with its mineral constituents. According to this process 20,000 cwts. of seaweed yielded 12,860 litres of empyreumatic oil, 31,000 cubic metres of illuminating gas, and 26 cwts. of iodine, besides other less important products.§ In spite, however, of the favourable expectations which were entertained by experts, this process has evidently failed in practice. The rock on which the invention has been wrecked is the troublesome and costly carriage of the seaweeds, since a great weight of water must be conveyed along with a comparatively small quantity of solid matter. Moride has indeed proposed to improve this method.

"Berichte über die Entwickelung der Chemischen Industr'e Während des Letzten Jahrzehends."

Leuchs, Deutsche Industrie Zeit., 1868, 408. Wagner Jahresber., 1868, 15.

+ Deutsche Indust. Zeit., 1867, 8.

Sticht, Wagner Jahresber., 1869, 221.

§ Wagner Jahresber., 1864, 186 (from Journal de Chim. Medic.). Moride, Comptes Rendus, lxii., 1002. Moniteur Scient., 1866, 445.