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212 The D-Lines Spectra Flame Examined by the Blowpipe. (Cheat

, bus powder is dissolved in about 10 c.c. of glacial acetic acid a large platinum dish over the flame of a treadle blowpipe by heating, fine needles of quinone crystallise out in the in the Royal Artillery Institution laboratory, I repeated cold, and melt at about 250° C., which proves that the the experiment with an ounce of pure crystalline boric powder always contains a large quantity of quinone; the acid. The platinum dish was cleaned with boiling nitric original crystals may be purer, but that the powder should acid, and subsequently with charcoal powder and distilled be considered as valueless impurities if the inelting points water. The fused boric acid seemed beautifully white are below 270° or above 280° is vague.

and pure, but, proceeding to test with it pyrologically, I My attention was particularly drawn to Dr. Versmann's found it became opaque on cooling, and therefore was table (CHEMICAL NEWS, vol. xxxiv., p. 178), test No.9, utterly useless for the purpose. showing 178 per cent at 268°, of which 9.8 per cent are (7.) I then became convinced that the apparent waste crystals and 7'7 powder.

of my time and boric acid was in reality an immense gain The Doctor gave me a part of the above sample to of fact, in furtherance of the conclusion I had so long prove to me the correctness of his statements, but I was entertained. Confirming the phenomenon with a new unable to find more than o'038 grm. of powder with a platinum spoon filled with pure crystallised boric acid mean melting point of 281°, whereas he finds 0.077 grm. before the blowpipe, it was impossible to avoid the con. not melting at 300° C.

clusion that these bulks of platinum, respectively heatable Dr. Versmann's method is not worth more than he only to redness by the different means employed, had not estimates it at, coinciding with my own views, and I ceased during the operation to emit the orange (or D-lines) doubt whether he will ever succeed in coming to a satisfame, which, absorbed by the boric acid in each case, bad factory final conclusion on this point."

rendered it opaque on cooling, and useless for pyrological (To be continued.)

purposes.

(8.) This hypothesis was confirmed in the following

manner:-A roll of new platinum foil, similar to (4), THE D-LINES SPECTRA FLAME EXAMINED BY secured by a piece of wire (a), was screwed in a geome. THE BLOWPIPE.

trical pen along with another wire (b), containing a bead

of pure, transparent, fused boric acid, in such a manner By MAJOR ROSS, late R.A.

that the point of the blowpipe pyrocone, heating (a) to red

ness, caused the orange (D-lines) flame to impinge upon (1.) IN 1871, at Mussoorie, India, a friend, Mr. Hen. (b), which, after a short exposure to this treatment, benessey, of the Indian Trigonome:rical Survey, since

came opalescent on cooling. elected Fellow of the Royal Society, invited me to inspect against the hypothesis of sodium being the cause of the

(9.) All now required to complete the negative evidence the then novel " atmospheric lines” of the solar spectrum; D-lines flame) was a proof of the converse of (8), viz., that through the large spectroscope lent him by the Royal Society, from the top of a mountain peak.

an undoubted sodium flame will not and cannot produce (2.) From a priori considerations, unnecessary to enter opalescence in a bead of pure sused boric acid. Knowing into here, I at that time suspected that the “D”” absorp- this to be the case, I went further

, and caused the orange tion lines of the solar spectrum are water lines, and not

flame from a bead of sodium carbonate to impinge upon due to sodium; and I communicated my supposition to

the opalescent bead (8) from a considerable distance in Mr. Hennessey, who rapidly appreciated the importance disappeared, and the bead was perfectly clear on cooling:

the geometrical pen. After a few seconds the opalescence of the deductions possible from such a standpoint. (3.) In the year above mentioned I found that emission

A ball of cobalt oxide floating in the bead, previously unof the so-called sodium flame, afforded by platinum before affected by the opalescence of (8), was now partially disthe blowpipe, was wholly dependent on keeping the solved, giving the whole bead a pink tinge. platinum at a red (not white) heat; so that the same wire,

(10.) Conclusions from Experiments (8) and (9). --The incandescent, and affording a continuous spectrum at the argument generally adopted by the defenders of the sodium point of the blue pyrocone, immediately produced an hypothesis of the D-lines flame is that the quantity of orange (or “D”-lines) tinge again when moved to a

sodium thus alleged to be indicated by the spectroscope cooler part, about a quarter of an inch inside the point, is too minute to be detected by any other means, but we and a reddish or rose tint when shifted to the extreme

have here incontrovertible evidence (a) that the reaction base of the pyrocone.

afforded by the orange flame emitted from platinum in pure (4.) I then confirmed this observation by heating a con

fused boric acid is an exceedingly strong one, and (b) that it siderable quantity of new clean platinum foil (compactly is exactly the opposite of that afforded by an undoubted so. rolled together by clean steel forceps), which, I ascertained, dium flame. Secondly, to believe that this flame is due to could not be incandescently heated by the mouth blow? sodium involves the mathematical absurdity of supposing pipe, and which therefore never ceased emitting the orange impart opalescence to boric acid, and also remove opal.

that sodium in combustion can, at one and the same time, fame. (5.) Conclusion from these Experiments. It is obvious,

escence from boric acid. It is therefore impossible to here, that it this orange flame (exhibiting spectroscopically believe that the orange flame emitted by red-hot platinum only D-lines) be due to sodium, that metal must be in is due to sodium ; and if this flame (exhibiting only D. some mysterious manner (a) proportional to the bulk of lines in the spectroscope) is not due to sodium in one the platinum used, and (6) eliminable from the blowpipe

case it cannot be due to that metal in any. flame according to the particular part of the pyrocone

(11.) If this evidence be admitted, as it apparently must, touched by the platinum. The logical conclusion,

to be absolutely incontrovertible, I will undertake to prove according to the sodium hypothesis, therefore, seems that in another paper) that the D-lines spectral fiame is in sodium exists both in pure platinum and in the blue reality produced by water, in the peculiar combined conpyrocone produced by the blowpipe, but that that, in a

dition found in hydrates, which I have termed " chemical certain state of heat, is required to eliminate it from this, water," and which Dr. F. Guthrie, advancing by other and that this must be only partially employed to develop methods of analysis, has termed " solid water." it in that. (6.) It was not until February, 1873, that I made any

Destruction of the Vineyards of the Côte d'Or.further progress towards a substantiation of the conclusion M. E. du Mesnil.— The vines of this important district I had formed in 1871, but that month, having several

are gradually perishing, though neither in the leaves nor weeks before successfully fused some phosphoric acid in the roots have the most skilful observers been able to find * This was written previously to the concluding part of Dr. Vers that some new enemy has made its appearance.-Comptes CHEMICAL NEWS,}

any indications of the phylloxera. The author thinks mann's paper in the last number of the Chem. News (vol. xxxiv,

Rendus.

201).

Action of Different Fatty Oils upon Metallic Copper.

213

ON THE ACTION OF DIFFERENT FATTY OILS UPON METALLIC COPPER.*

By WILLIAM THOMSON, F.R.S.E., F.C.S.

(Concluded from p. 201.)

Series II.-LONG STRIPS of Copper USED, HALF COVERED WITH OIL.

(Commenced November 9, 1875. Examined August 9, 1876.)

Name of Oil.

Appearance of oil when examined.

Appearance of strip of copper.

Felative amounts

of copper con-
tained in solution

in the oil.

· Relative amounts

of the copper salt
dissolved by water.

Relative amounts ci acidity given

to water.

seem

1. Mesina Olive Oil. Yellowish colour and quite Thickly coated with green Absent. Absent. Very small. limpid.

salt of copper, which hung
thickly in flakes from the

plate. 2. (Sweet) Olive Oil, Ditto, but with a slight green. Thickly coated with green Very small. Minute Absent. ish tinge. copper salt, but not hang

trace.

ing in flakes. 3. Cotton Seed Oil. The appearance of the oil The copper slip is coated Very small. Ditto. Larze.

does not to have with a very thin coating
changed; it has left a coag- of a dark deposit.
ulated rim all round the
bottle at the surface, like a

series of icicles. 4. Pale Rape Oil. The oil has a greenish colour; The copper slip is covered Large. Small. Trace. otherwise not changed. with a green salt of cop

per immediately at the
surface of the oil; under.

neath it is quite bright.
5. Brown Rape Oil.
Ditto.

The slip is covered imme. Large Small. Trace.

diately at the surface
with a green deposit ;
underneathitis free from,
green deposit, but slightly
covered with a dark de-

posit. 6. Castor Oil.

The oil appears to have The slip of copper at the Rather Small. Minute changed to a distinály immediate surface of the large.

trace. green colour.

oil is covered with a dark
deposit ; underneath it
is almost bright, being
slightly covered with a

greyish deposit. 7. Raz Linseed Oil. The oil has changed to a deep The slip is slightly and Very large. Very large. Very large. green colour.

irregularly covered with
a dark coloured deposit
only slightly adhering to
the surface of the cop-

per. 8. Palm Nut Oil. The appearance of the oil has the slip is covered with a Absent. Absent. Rather not changed. thick green coating like

large. the one placed in olive

oil. 9. Ground Nut Oil. Ditto

The slip is covered with a Trace. Absent. Trace,

dense coating of green
copper salt, the coating
being thickest near the

surface of the oil. 10. Pure Lard Oil. The oil has assumed a very The slip is covered with a Moderate. Trace. Small.

slightly greenish shade. thin light green coating. II. American Tallow The oil has the appearance The slip is covered with a Absent. Absent. Moderate. Oil.

of honeycomb, the cells dense green deposit of
being formed by the solid copper salt thickest near

fat and mixed with thin oil. the surface. 12. Common Tallow The oil is of a yellowish colour Ditto.

Absent. Absent. Rather Oil. and turbid from crystalli

large. sation of solid fat.

* Read before the British Association, Glasgow Meeting Section B.).

214

Action of Different Fatty Oils upon Metallic Copper. Chr. At, saya

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over

13. North American This oil has undergone no The slip is irregularly Small, Absent. Absent.
Neatsfoot Oil.
apparent change.

covered with green de-
posit in a net form all

its surface, but
thickest nearest the sur-

face. 14. English Neatsfoot The oil has changed to a dis. The slip is covered with a very large. Small. Absent. Oil. tinctly green colour.

very slight dark coloured

deposit. 15. American Sperm The oil is of a dark yellowish The surface of the copper Extremely Very large. Large. Oil. colour.

is thoroughly bright. Ex- large.
cept in a line where it
was touched by the im-
mediate surface of the
oil, it has a faint line of

a greenish deposit. 16. Whale Oil. Oxidation had taken place the copper was absolutely Absent. Absent. Very large.

and penetrated from the bright throughout.
surface of the oil to about
a quarter of its entire depth,
forming it into a hard jelly.
Underneath this jelly the

oil was quite liquid. 17. Pale Seal Oil. The oil all round the glass The copper slip was ab- Large. Large. Rather at its surface had coagu- solutely bright through

large. lated, forming a circle of small icicle looking bodies; otherwise the oil did not

seem to have changed. 18. Mineral Oil (lubri. The oil is of a dark reddish The slip is covered with a Absent. Absent. Absent. cating). yellow colour.

very slight brownish de-
posit.

out.

These results may be classified as follows :

oils only partly immersed, two samples have produced green First. The amount of acid dissolved by the water from deposits only at the point where the slips came in contact the oils seems to bear no relation to the amounts of copper with the immediate surface of the oil." These were pale dissolved by the oils. In some cases the acidity is large rape-seed oil and brown rape-seed oil, and one where the and the amount of copper found in solution small or line of green deposit at the surface was exceedingly absent, and in others the acidity is small and the amount narrow and very slight, viz., American sperm oil; lastly, of copper found in solution large.

one sample covered the surface of the copper slip with a Second. As a rule, when the amount of copper dissolved network of green deposit, viz., North American neatsfoot by the oil is large the amount extracted by water is also oil. large, but in a few cases this does not seem to be so. It is most remarkable that no samples of fish oil, with

Third. Some oils produced on the surface of the copper the very slight exception above named of American sperm slip a complete coating of a green salt of copper of a oil, produced any deposit of green salt of copper on the greater or less degree of thickness, and it is remarkable metallic slips ; the surfaces of the copper placed in each that those oils which have this action have not in any of the thirteen different samples used in both series having case dissolved more than a trace or small quantity of the been preserved in a perfectly bright condition. copper, and in some cases no topper in solution was Fourth. As a rule those oils which dissolved large pro found. The following is a list of the oils which have this portions of copper, left the surfaces of the copper slips in p'culiar action in the first and second series respectively:- as bright, or almost as bright, a condition as when they

were first introduced. Of the oils belonging to this class Series I.

Series II.

may be mentioned:Mesina olive oil.

Olive oil. Olive oil,

Series I.

Series II.
Olive oil.
Palm oil..
Palm nut oil.

Refined rape oil.

Pale rape oil.

Linseed oii.
Foreign neatsfoot oil.

American sperm oil.
Ground nut oil.
English neatsfoot oil.

Pale seal oil.
American tallow oil.

Sperm oil.
Tallow oil.

Raw cod-liver oil.
Common tallow oil.

Newfoundland cod oil.
Lard oil.

Common seal oil. Some oils fall partly under this classification inasmuch Some oils in the second series, whilst dissolving large as they are not completely covered with the green deposit quantities of copper, left the surfaces of the metal more or but are not entirely free from it. In the first series two less tarnished. Of these may be mentioned :- Brown oils have covered some parts of the copper plate with a rape oil, castor oil, raw linseed oil, English neatsfoot oil. blackish deposit and other parts with a green deposit, viz., The following samples dissolved moderate or small one of the samples of cotton-seed oil and lard oil.

quantities of copper, but left the surface of the slips quite In the second series, where the copper slips stood in the bright :

ON THE

CHEMICAL, 85625;}
Development of the Chemical Arts.

21 Series I.

Series II.

the microscope by means of polarised light, it crystallises Seal oil.

in beautiful small star-like groups of crystals, which have Pale seal oil.

the power of polarising light. This white body is difficultly Whale oil.

soluble in alcohol in the cold, but dissolves with facility Cod oil.

in hot alcohol. It is easily soluble in ether. I intend to Shark oil.

continue my enquiry into the properties and composition East Indian fish oil.

of these bodies. For Series II., as only three fish oils were employed,

Royal Institution, Manchester, only whale oil remains to be placed in this class, although

September 30, 1876. 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

REPORT 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

DEVELOPMENT OF THE CHEMICAL ARTS deposit. The following is a list of those having this pe- DURING THE LAST TEN YEARS.* culiar action:

By Dr. A. W. HOFMANN.
Series 1.

Series II.
Rape oil (not refined). Brown rape oil.

(Continued from p. 197.)
Pale cotton-seed oil. Cotton-seed oil.
Ordinary cotton-seed oil. Raw linseed oil.

Chlorine, Bromine, Iodine, and Fluorine.
Almond oil.
English neatsfoot oil.

By Dr. E. Mylius, of Ludwigshafen. Lastly. The three samples of mineral oils in both series As regards recently discovered sources of iodine we have produced on the coppe: slips a peculiar characteristic de already mentioned the mother-liquor of Chilian nitre. posit, of a greyish colour.

No others of importance have been discovered. Leuchst Many of the samples in the first series dissolved only a indeed points out that the flue dust of blast-furnaces contrace or very small quantity of copper, but only two were tains compounds of iodine along with other soluble salts. absolutely free from even a trace of that metal, viz., Thus from the dust of the Rosenberg furnace, near SulzEnglish neatsfoot oil and tallow oil. In the second series berg, he obtained o'034 per 1000; from the Komoran five samples came under this class, viz., one sample of furnace, near Herzowitz, o`042; and from that at Kreutzolive oil, palm nut oil, American tallow oil, common thale, oʻ146, and calculated that 35} lbs. iodine could be tallow oil, and of whale oil which was protected from the annually prepared at the first mentioned furnace. But air by a thick coating of oxidised oil on its surface. even in the improbable event that the iodine thus oc

With the view to further examine the green copper salt curring could be extracted at a remunerative cost the incrustation which had been produced on the slips of total production would still be quite insignificant. copper in some of the oils, I took the slip which had been As for the total production of iodine there exist few left in contact with No. 1 olive oil of the second series, numerical statements from which it can be ascertained. which was covered thickly by the incrustation, and from By far the greatest quantity is obtained in England and which it hung in flakes : this was carefully scraped off, France. In the year 1871 the quantity produced in Great and part of the excess of oil absorbed by blotting-paper. Britain reached 114,799 lbs., 9-10ths of which came from The incrustation was then transferred to a test-tube, and Glasgow. One of the works there (W. Paterson) in the washed by decantation with petroleum spirit : this dis year 1867 alone produced 112,000 lbs. In France the solved the excess of olive oil, together with a copper salt production in 1867 was 55,600 kilos. ; therefore rather which coloured the petroleum spirit of a deep blue-green less than in England. colour on its first treatment. The incrustation was washed In 1868, 40 kilos. were daily prepared at Tarapaca from so long as the spirit continued to dissolve any copper; Chilian nitre (Balard) corresponding to a yearly producthe petroleum spirit solution was then filtered, and the tion of 290 to 300 cwts. This quantity, however, must filtrate evaporated on a water-bath, to drive off all the be considerably reduced if we remember that Stichell spirit. The residue—which consisted of the excess of found only 50 per cent of real iodine in a Chilian sample. olive oil, together with the soluble copper salt-was set The method of extracting iodine is essentially unaside to cool, and in the morning the copper salt was changed notwithstanding many proposed improvements. found to have crystallised out in beautiful green feathery In the Report of the London Exhibition of 1862, A. crystals.

W. Hofmann describes the process of Stanford which was Ferrocyanide of potassium, added to and shaken with then taken up with great zeal, and for which a medal was the petroleum spirit solution of the soluble copper salt, at

awarded by the jury. Its principle is the preliminary disonce decolourised the liquor, and threw down all the cop- tillation of the seaweed, and the utilisation both of the per on the ferrocyanide.

volatile products and of the residual charcoal with its The insoluble copper salt, or part of the incrustation, mineral constituents. According to this process 20,000 was then submitted to examination. It is a deep green cwts. of seaweed yielded 12,860 litres of empyreumatic solid, lighter than water, and insoluble in that medium. oil, 31,000 cubic metres of illuminating gas, and 26 cwts. Part of this salt was placed in a test-tube, and water of iodine, besides other less important products. In added, which was gradually heated till about 200° F., when spite, however, of the favourable expectations which were the solid melted to a deep green oily liquid, which floated entertained by experts, this process has evidently failed in on its surface. It is insoluble in alcohol, slightly soluble practice. The rock on which the invention has been in bisulphide of carbon and in ether, and is decomposed wrecked is the troublesome and costly carriage of the sea. when heated with most of the acids.

weeds, since a great weight of water must be conveyed Some of the salt was heated in a test-tube with very along with a comparatively small quantity of solid matter. weak hydrochloric acid, the copper was separated and Moride has indeed proposed to improve this method. dissolved in the water solution of acid, whilst a clear, transparent, oily liquid floated on the surface, which when

* “Berichte über die Entwickelung der Chemischen Industrie

Während des Letzten cold solidified to a white compact solid, resembling in + Leuchs, Deutsche Industrie Zeit., 1868, 408. Wagner Jahresber., appearance bees'-wax, It, however, differs from this and 1868, 15. the well-known solid fatty acids by the peculiar way in

* Deutsche Indust. Zeit., 1867, 8. which it crystallised when placed on a warmed microscope

|| Sticht, Wagner Jahresber., 1869, 221.

$ Wagner Jahresber., 1864, 186 (from Journal de Chim. Medic.). slide and allowed to cool gradually. When viewed through i Moride, Comptes Rendus, lxji., 1002. Moniteur Scient., 1866, 445,

ends."

216
Composition and Quality of the Metropolitan Water.

CHEMICAL News,

Nov. 17 , 1876. He proposed to dry the weeds in portable furnaces where pp. 85 and 119-120) a peculiarity-if not an error-- in the they are obtained, but nothing further has been heard of formulæ occurs which is likely to be misleading. Your the distillation of seaweed and the production of iodine correspondent “R. P. D.," who writes to correct M. from the residual charcoal.

Carnot's figures (p. 122), has already misunderstood his The method of extracting iodine from the mother- meaning. liquors of kelp is still the same well-known process over M. Carnot, in every instance (excepting one evident which it is needless to waste a word. New methods have typographical error), expresses sulphide of bismuth-in been proposed, but have led to no alterations in practice. the old notation-Bi2S3 instead of BiSz as—in that notaWe may mention the method invented by Lauroy.* Hetion-it is generally written. It is written in the same saturates the mother-liquors of Varec with hydrochloric manner in the Comptes Rendus, from which one of the acid, removes the precipitate thus produced, and passes articles was translated. Either M. Carnot is in error, nitrous and hyponitrous acid into the clear liquid. Iodine or he uses one-half the usually accepted atomic weight is thus precipitated, whilst the bromides, simultaneously for bismuth. present, are not decomposed.

If “ R. P. D.” will either substitute Bi for Biz in the The process of extracting iodine from the mother-liquors formula of which he writes, or will halve the weight of of Chili nitre, which was at first introduced by Thiercelin bismuth, he will find that M. Carnot's original figures are in the works of the Société Nitriere, at Tarapaca, and by correct.-I am, &c., which, as has been already stated, 40 kilos. of iodine were

ALFRED SENIER. obtained there daily, is in brief as follows:-The iodic

School of Pharmacy, 17, Bloomsbury Square, W.C.,

November 14, 187,6. acid present in the mother-liquors is reduced by an exactly sufficient amount of sulphurous acid. The iodine thus precipitated is placed upon a sand filter in a large stoneware vessel with a perforated bottom, which allows CHEMICAL NOTICES FROM FOREIGN the greater part of the saline liquid saturating the iodine

SOURCES. to drain away. It is then transferred by means of stoneware spoons into a trough of gypsum with thick sides, which quickly absorbs the rest of the liquid. The crude Note.--All degrees of temperature are Centigrade, unless otherwise iodine thus obtained is either offered for sale in this state expressed. or submitted to sublimation. Thiercelin subsequently employed for the precipitation of the iodine nitrous acid, Comptes Rendus Hebdomcdaires des Seances, de l'Acade:nie which he obtained by the ignition of a mixture of 5 parts

des Sciences. No. 17, October 23, 1876. soda-saltpetre, and I part charcoal (Duhamel's process for the manufacture of soda).

The Electric Effluve.-M. A. Boillot.-Two tubes

filled with powdered graphite are fixed in a parallel posi(To be continued).

tion side by side, but at a variable distance, depending on the intensity of the electricity and on the nature of the

effluve which it is desired to obtain. Each of these tubes CORRESPONDENCE.

is fitted at one end with a platinum wire communicating

with the carbon within, these wires being opposed to each NEW REAGENT FOR POTASSIUM.

other, and placed in external connection with the elearic source. The effluve is produced along the entire length

of the tubes. The gases to be operated on arrive at one To the Editor of the Chemical News.

of the extremities of the apparatus, and are collected at Sir,-- In the reports of M. Carnot's experiments upon a the other after having traversed a tube intermediate benew reagent for potassium (CHEMICAL News, vol. xxxiv., tween the two others filled with carbon, and after having * Lauroy, Monit. Scient., 1868, 1042.

undergone the action of the effluve. COMPOSITION AND QUALITY OF THE METROPOLITAN WATER,

OCTOBER, 1876.

The following are the returns of the Society of Medical Officers of Health :

Ammonia.

Hardness on Clark's Scale.

Appearance in

2 foot Tube.

Nitrogen as Ni

trates, &c.

Organic.

Oxygen used to
Oxidise Organic

Matter.

Saline.

Total Solids.

An-
Sulphuric

hydride.

Magnesia.

Lime.

Chlorine.

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Grs,

Grs.

Grs.

Grs.

Grs.

O'000 0'000

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Grs.
Grs. Grs. Grs.

Degg. Degs.
Thames Water Companies.
Grand Junction

Clear

0.008 0.135 0'084 20:40 8.288 0*396 0.94 1.80 13:80 2:4 West Middlesex

Clear
0.008 0.135 0082 20:41 88064 0468

1.66 13.80 24 Southwark and Vauxhall Slightly turbid O'00I o'008 0'105 0*050

20'20 8'232 0 468 I'OI 1'53 13.80 2:3 Chelsea

Clear

0'007 O'120 0'077 20-90 8-344 0'468 I'OI 1'73 13.80 3.8 Lambeth ..

Clear

0'007 Oʻ120 0:ogi 20.06 8:128 0:442 I'or 173 14'30 33 Other Companies. Kent .. Clear

O'255 o'ΟΙΟ 24'24 10-248 0*576 1'13 1'93 18.20 5:1 New River

Clear

0'004 0*120 0.027 19'38 76952 0468 0.87 0.80 14:30 3:3 East London ..

Clear

0'000 0·005 0·105 0.037 19-51 7:616 0.568 1.85 1.60 13:30 3:4 The quantities of the several constituents are stated in grains per imperial gallon of 70,000 grains. NOTE.— The amount of oxygen required to oxidise the organic matter, nitrites, &c., is determined by a standard solu.

tion of permanganate of potash acting for three hours and in the case of the Metropolitan waters the quantity of organic matter is about eight times the amount of oxygen required by it.

C. MEYMOTT Tipy.

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