Obrazy na stronie
PDF
ePub

2.

[ocr errors]
[ocr errors]
[ocr errors]

82
Chemical Notices from Foreign Sources. {

August 25, 1876. glass or porcelain tubes, and was enabled to perform com- | nitrogen, Berzelius adds—“Il semblerait, d'après cela, bustion after combustion with the greatest ease.”

que le degagement d'oxygene dans ces animaux est du å Before applying the platinum tube to the direct com- traction du soleil sur la chlorophylle qu'ils contiennent,” a bustion of iron or steel," an experiment was tried with singularly sagacious conclusion, and one that ought to inpure sugar to ascertain whether a stream of oxygen, in duce those interested in water-supply to have this matter conjunction with a layer of only 4 inches of cupric oxide thoroughly investigated by competent individuals, for it is would be sufficient to convert all the carbon into carbonic quite possible that the growing of water-cresses, for anhydride. The result was perfe&ly satisfactory, an instance, and the purification of water are more nearly amount of carbonic anhydride being obtained equal to related to each other than directors of water companies 42.086 per cent of carbon instead of 42'105, showing a loss i imagine. of only o'019 per cent upon the theoretical amount.”

That chlorophyll performs important duties in both the To prove that a platinum tube is equally applicable in vegetable and animal economy seems certain, though its the case of small quantities, I give the results of duplicate powers as yet are undefined and but little understood. estimations of carbon in steel by direct combustion : Still, however, we can notice that it invariably exists on

the surface of the living leaves of plants, also in the bile, I'180 0'921 0°763 0-649

0'359

and sometimes in the blood of animals; and within the I'151 0'922 0'759

0.620 0'359

last two years it has been discovered that the spots and 0°758

colouring found upon the eggs of birds is chlorophyll ;

and, in some cases, as in the egg of the hedge-sparrow, The expense of platinum tubes has probably millitated this chlorophyll is blue (which seems, indeed, to be the most against their general use, but where a number of colour of pure chlorophylì, as will be explained on a subanalyses has to be made this would soon be compensated sequent occasion, when speaking of the composition of for by the saving of time and glass tubes.—I am, &c., bile, a matter now under examination). For the present

W. DOUGLAS HERMAN. we may remark that room enough exists to warrant enerCropper's Hill, St. Helens, Lancashire,

getic interference on the part of our Metropolitan water August 21, 1876.

directors with the closely-allied subjects of water-purity

and water-jobbery; because it may so be that Nature's THE PRESENCE OF NITRITES IN THE WATER remedy is staring them in the face whilst they are blindly OF THE THAMES.

hunting by expensive methods to perform a really inexpensive cperation, and thus uselessly sinking an im

mense capital that will have to be paid for hereafter, and To the Editor of the Chemical News.

therefore in all time to come limit the use of Heaven's SIR,—The following experiments were made with a view greatest boon throughout the largest metropolis in the to ascertain whether nitrites of any kind existed in Thames world. We have already seen something of this kind water ; but although the process employed was one brought about in the case of coal-gas, the price of which capable of detecting the ten-thousandth part of a grain of in London at the present moment would not have been any nitrite whatever, yet it totally failed in this instance more than two shillings per 1000 cubic feet had matters to indicate even a trace. The first experiment was made been left to the wholesome action of common sense and upon Thames water which had been purposely allowed to honest competition. But all the benefits arising from imconcentrate in a steam-boiler until 400 cubic feet of it had provements and economies in gas-making during the last been reduced to 8 cubic feet, and of this concentrated twenty years has been swallowed up by expensive Ads of water i gallon was evaporated down to the bulk of 100 Parliament and engineering jobbery, so that the price grains, when it was tested in this manner :-One drop of remains almost unchanged, and is, perhaps, unchangeable. the water in question being placed on a clean white por

&c., celain slab, a corresponding drop of a solution of the

LEWIS THOMPSON. protochloride of iron was put close to it, and then the two drops were made to unite by means of a platinum wire, but no visible effect was produced in consequence of the admixture.

CHEMICAL NOTICES FROM FOREIGN The water in this case had been obtained about 1 mile

SOURCES. below London Bridge, and a precisely similar negative result was derived from water taken near Vauxhall Bridge, although the amount of concentration was then six times Note.-All degrees of temperature are Centigrade, unless otherwise greater than in the first instance; consequently we cannot

expressed. regard the existence of nitrites in Thames wate as an established fact : and here, perhaps, it may be as well to Comptes Rendus Hebdomadaires des Seances, de l'Acadenie remark technically that the nitrites in general, but

des Sciences. No. 4, July 24, 1876. particularly the nitrite of soda, possesses many advantages Observation of the Portion of the Spectrum Below over the bisulphite of soda for what is called an “anti-the Red Ray by means of the Effects of Phosphorchlore.” It is more easily made, it is cheaper, and after escence.-M. E. Becquerel.—We may follow by direct being used it may be recovered by evaporation in the form vision some of the effects produced in this region of the of nitrate, and again converted into nitrite for repeated spectrum. We find thus merely some rather large absorpuse. Moreover, it does not by its employment lead to the sion-bands, and to distinguish these it is necessary to have production of an acidulously destructive compound like a very intense light. It is probable that many lines and bisulphate of soda, because the nitrite of soda, when used narrower bands may escape this means of observation. as an antichlore, is merely converted into a neutral nitrate, The margins of the images are not well defined, except after having arrested the injurious influence of two atoms those of the region A", A'" (the more and the less reof chlorine.

frangible parts of the spectral region below the red). On Whilst upon the subject of Thames water, it is in the other hand, the observations do not extend' much teresting to review an observation made by Berzelius, beyond A", and do not comprehend all the space where which may be found at page 686 of the fifth volume of his the thermic phenomena are observable. This may depend “Chemistry,” translated into French by Valerius. _After on the limits within which the effects of phosphorescence quoting numerous experiments made by Wohler, Ehren. are appreciable, and which may not be the same as those berg, and Morren, which prove that the effect of infusorial of the thermic spectrum. The author's method is to fix a animals in water is to oxidise the water, and generate an highly phosphorescent substance, such as an alkalineair contatning 51 per cent of oxygen and 49 per cent of earthy sulphide, upon paper or glass by means of gum, and

-I am,

83

.

CHEMICAL News,

Chemical Notices from Foreign Sources. August 25, 1876. having excited it by the action of diffused light to observe , dered insensible, though it turned very quickly if a vacuum the extinction of phosphorescence produced by this part of was made without heating in the ordinary manner. But the spectrum. This extinction causes unequally active if the discs, instead of being made of two metals, were parts to appear, i.e., spaces corresponding to the black made half of metal and half of mica the instrument could rays or bands of the spectrum.

not be rendered insensible. The glass case was pierced Paraldol, an Isomeric Modification of Aldol.-M. by an ele&ric discharge, when the radiometer began to A. Wurtz.—This compound softens at 80°, and is melted turn with great speed, and continued for an hour. The at 90°. It dissolves readily in water and alcohol, from aperture was so small that its diameter could be approx. which latter it is obtained in fine anorthic prisms.

imately estimated only by the aid of a powerful micro

scope. It was found practicable to re-form a vacuam in Reply of M. Hirn to the Criticism of M. Ledieu in this instrument up to 100 m.m., even though perforated; “ Comptes Rendus," July 10, 1876.-M. Hirn com

rotation then took place in the ordinary manner. Nos. 6, plains that M. Ledieu ascribes to him the very views 7, and 8, are radiometers with discs of mica and varnished which he is attempting to refute.

copper, green, blue, red, and yellow; the colours, in these Production of the Electric Effluve.-M. A. Boillot. conditions, have no effect on the radiation. -The author, in experimenting upon the chemical action Cause of the Motion of the Radometer.-M. G. of the effluve, makes use of the following arrongement:- Salet.-According to all the experiments made, the cause Two narrow tubes, filled with graphite in powder and of movement in the various apparatus resembling the calcined, and are parallel to and near each other. They radiometer of Crookes is a difference in the temperature are inserted with their whole length in a test-tube about of the surfaces of the discs. The theory of Tait appears 18 centimetres in length, and they terminate each with a the best. A disc, compound or simple, whose surfaces platinum wire communicating with the carbon. The wire bave actually two different temperatures, and which is from one of these tubes traverses the test-tube to its upper plunged into a highly rarefied atmosphere, begins to move, part; the other is bent back in a downward direction. the hottest surface recoiling. Whilst the difference of Two other tubes enter the test-tube ; the one ends at the temperature exists the movement continues. There is no summit, and the other penetrates to 2 or 3 centimetres of occasion to bring forward the possible action of gases conthe orifice. The first is destined to introduce the gases, densed on the surfaces. Wherever two thermometers, and the second to collect them. The effluve is produced isolated in a vacuum, and constructed of two different in the space between the two carbon conductors.

substances, A and B, would indicate different temperatures, Photometric Researches on Coloured Flames.- a radiometer disc composed of adjacent laminæ, the one M. Gouy.-Not suitable for abstraction.

of the substance A and the other of B, will begin to move, Note on the Radiometer.—M. A. Gaiffe.—The and the movement will show the direction and the degree author has made a modification, which he considers proves the discrepancy between the indications of two thermo

of the difference of temperature. In the circle of lights that the aginic and thermic rays act upon this instrument meters, the one with its bulb blackened maintained itself It is a radiometer of the ordinary form, the discs being for an indefinite time; it is the same with the movement coloured a dead blue on one surface and a dead red on

of the radiometer. Not content with repeating the exper-the other. It may be made to revolve in either direction by using alternately suitable sources of heat and light. meter in the centre of a sphere of opal glass so as to

ment of Mr. Crookes and M. Fizeau, by placing the radioIt

, e.g., we expose this instrument to the sunlight, the equalise the light and avoid currents of air, the author has blue surfaces acquire a predominant action, and after some moments hesitation the mill begins to turn from the left strative. He has fixed upon the mill of a radiometer the

made an experiment which he considers absolutely demon. to the right. If it is exposed to the flame of a common gas-jet, or of a Bunsen burner, or to the radiations of a laminæ of burnt mica, one of them blackened. Under the

needle of a compass: the discs were composed of two plate of hot iron the rotation takes place in an inverse influence of an adjacent flame the needle deviated to a direction.

certain angle, and variations in the lustre or in the dis. Radiometers composed of Laminæ of Different , tance of the fame were shown very distinctly by a correMaterials.—MM. Alvergniat Freres.—The following ob. sponding change in the deviation. The source of light servations have been made with radiometers with discs of having remained constant for four days the needle kept its different materials. No. 1 is a radiometer with discs of position invariable for the whole of the time. The action silver and transparent mica. In the light the radiometer of condensed gases cannot be invoked here. turns with the mica in front and the silver repelled; in obscure heat, with the radiometer plunged in water at

Decomposition of Alkaline Bicarbonates, Moist or 30° or 40°, the rotation is in the opposite dire&ion. In ice Dry, under the Influence of Heat and of a Vacuum. it turns as if exposed to light. No. 2 is composed of soda is not sensibly decomposed in a vacuum at 20° to 25°;

- M. A. Gautier.- Perfectly pure and dry bicarbonate of aluminium and blackened mica. In the light this radiometer turns with the metal first, and the blackened surface ! At 100° it is rapidly decomposed in dry air. Solutions of repelled. Obscure heat and light, however intense, do not

bicarbonate of soda in water set to evaporate in a vacuum modify the direction of the rotation. If plunged in ice it

are decomposed at 20° to 25°, and this the more rapidly

The bicarbonate of turns in the opposite direction. No 3 is formed of alu- the greater the quantity of the water. minium and mica not blackened. In light this radiometer potassa is decomposed much less rapidly at elevated tem. turns with the mica first. In ice the rotation is in the peratures than the corresponding soda salt. same direction as in light. Dark heat niakes it turn in the Geological Age of Certain Metallic Veins, and, in opposite direction, with the metal first. With this radio particular, of Mercury.-M. Virlet d'Aoust.–The author meter M. Jamin made the following experiment:–He concludes that in the Asturias, as in Mexico and France, directed a small light upon one point of the radiometer mercury is of very modern origin. while in motion, so as to heat only a single point of the globe. This threw the discs into such a state of equilibrium, that instead of rotation there ensued oscillations like those of a pendulum. The two surfaces of the discs,

Les Mondes, Revue Hebdomadaire des Sciences, the metal and the mica, are both repelled: if the distance

No. 14, August 3, 1876. of the flame is varied one of the two laminæ is repelled Occurrence of the Germs of the Tape-worm in more or less. No. 5 is a radiometer with discs of ‘silver Meat.-An article taken from the Abeille Medicale points and aluminium. This radiometer has been heated to 440°, out the danger of eating meat in the half-raw condition, distilling sulphur, and continuing to make a vacuum with called by some persons " rare," as the ova of the tapethe aid of the mercurial pump. The instrument was ren- worm are only killed by thorough cooking. Those whose

84

manner.

Patents.

{ CHEMICAL NEWS,

Augnst 25, 1876. tastes lead them to select meat in this condition are re. dered into a condition capable of being dissolved in water. Orinstead

of employing any of the before-mentioned alkaline compounds or procommended to eat the flesh of the horse, which is less in

ducts, I submit the phosphate of alumina by preference in a finelyfected by the Tænia than the ox, sheep, or pig.

divided condition in conjunction with sulphate of soda, coal, or other carbonaceous matter to the action of heat in order that the phosphoric acid, together with the alumina, shall be converted into a soluble

condition. MISCELLANEOUS.

Improvements in dyeing. E. T. Hughes, Chancery Lane, London. (A communication from G. C. F. Bartels and E. F. Freise, Goetlingen, Hanover, Germany.) May 11, 1875.-No. 1764. This consists in

chemical combination of mercaptane, which has great affinity to both British Pharmaceutical Conference.-(Thirteenth vegetable and animal fibres, whereby instead of using several baths Annual Meeting, Glasgow, 1876. Tuesday, September 5,

for the different kinds of fibres as heretofore, but one bath is required,

and tissues of mixed fibres may be dyed with one bath. and Wednesday, September 6).--The following papers are Improvements in the treatment of animal blood, also of fibrous matealready promised :

rials, and in the manufacture of manures therefrom. G. F. Snelling, 1. “ Liquid Extract of Pareira." Mr. Barnard S.

Edith Terrace, Victoria Road, Upton Lane, Essex. May 19, 1876.

No. 1844. This relates (1) to the treatment of animal blood in special Proctor.

(2) To the treatment of shoddy and woollen and cotton 2. “ Variation in the Strength of the Preparations of rags in a special manner. (3) To the manufacture of manures from Opium.” Mr. D. B. Dott.

the above ingredients, separately or combined with other ingredients,

such manures containing large fertilising properties. which free them. 3. “ Report on the Assay of Opium for Morphia.” E.

selves by or in contact with moisture aiter application to or upon the L. Cleaver, F.C.S.

soil. 4. “ Note on the Assay of Opium.” Mr. Barnard S.

Improvements in the treatment of sewage. M. F. Anderson, Priory Proctor.

Road, Coventry, Warwick. May 19, 1875.–No. 1845. This Proví.

sional Specification describes drying sewage sludge by adding to it 5. “New Derivatives from the Opium Alkaloids.” Dr. coprolite and sulphuric acid. Wright, F.C.S.

Improvements in deodorising blood to enable it to be used for 6.*** The Presence of Free Acetic Acid in Opium.” Middlesex. May 20, 1875.-No. 1855. This consists in mixing blood

manuring and other purposes. J. Smith, Cattle Market, London, David Brown, F.C.S.

with suitable proportions of phosphate of lime or ground coprolites, 7. “ New Excipients for the Official and other Pill calcic oxide, and sulphuric acid (or

by preference ammonia lignine Masses." Mr. G. Welborn.

saturated with sulphuric acid), the mixture being well stirred as the

different ingredients are added. 8. "The Preparation and Preservation of Phosphorus Improvements in and relating to the obtainment of phosphorus and Pills." Mr. T. Haffenden.

Phosphides. J. Townsend, Glasgow, Lanark, N.B. May 21, 1875.9. “Notes on some Salts of Pilocarpine."

Mr. A. W. No. 1862. This invention consists in the utilisation, as a source of

the phosphorus and phosphides, of phosphate of alumina; and the Gerrard.

kind known as Rodonda phosphate answers quite well, although other 10. “Report on the Aconite Alkaloids." Dr. Wright, varieties will do so also. F.C.S.

Improvements in photometers. W. Morgan-Brown, Southampton 11. “The Solubility of Cinchona Principles in Glyce- Paris.) May 21, 1875.-No. 1865.

Buildings, London. (A communication from O. Shuette, Rue Gallion,

This invention consists in rine." Mr. T. Andrews.

measuring light by interposing one or several thicknesses of slightly 12. "The Therapeutic Value of the Aloins.” Dr. opaque substances, as paper, carrying increasing numbers, by which Tilden, F.C.S.

figures the relative intensity of the light is measured. 13. “The Active Principle of Capsicum Fruit.” J. C. Thresh, F.C.S.

NOTES AND QUERIES. 14. “ Report of the Oxidation of the Essential Oils." Part IV. C. T. Kingzett, F.C.S.

Analysis of Water of River Hooghly.-Can any of your readers 15. “Report on the Essential Oil of Sage.” M.M. P. I inform me if any analysis of the water of the River Hooghly, in India, Muir, F.C.S.

has ever been published, and where it may be referred to ? 'I desire to 16. “Note on the Benzoates in Suint.” Mr. A. Taylor. consult such an analysis if possible.-F. J. Rowan.

17. “ Notes on the Colouring Matter of Crocus Sativus." W. W. Stoddart, F.C.S.

COLLEGE, MANCHESTER. 18. “ Pekoe · Flower'-or, Hair of the Tea Leaf.” T.

Principal-J. G. GREENWOOD, LL.D. B. Groves, F.C.S.

Professors and Lecturers. 19. "A New Form of Plaster of Cantharides.” Mr. A. Greek-J. G. Greenwood, LL.D., Fell. Univ. Coll., Lond. W. Gerrard.

Latin; Comparative Philology–A. S. Wilkins, M.A., Fell. Univ. Coll,

Lond. 20. “A Proposed Solution of Citrate of Iron and English Literature ; Ancient and Modern History-A. W. Ward, Quinine.” Mr. J. F. Brown.

M.A., Fell. St. Peter's Coll., Camb. Preliminary Report on the Chemistry of Ivy.” | English Language-T. Northcote Toller, M.A., late Fell. Christ's R. H. Davies, F.C.S.

Coll., Camb.

Mathematics—Thomas Barker, M.A., late Fell. Trin. Coll., Camb. 22. “Supplementary Note on Phosphate Syrups.” W. Natural Philosophy; Physical Laboratory–Balfour Stewart, M.A., L. Howie, F.C.S.

LL.D., F.R.S.,; Thomas H. Core, M.Á. 23. “On Filtering Papers.” Thomas Greenish, F.C.S. Civil and Mechanical Engineering Geometrical and Mechanical

Drawing-Osborne Reynolds, M.A., Fell. Queen's Coll., Camb. Logic and Mental and Moral Philosophy; Political Economy-Robert

Adamson, M.A.

Jurisprudence and Law,Alfred Hopkinson, M.A., B.C.L., Stowell
PATENTS.

Fell. Univ. Coll., Oxford.
Chemistry and Metallurgy-H. E. Roscoe, B.A., Ph.D., F.R.S.

Organic Chemistry-C. Schorlemmer, F.R.S.
ABRIDGMENTS OF PROVISIONAL AND COMPLETE Animal Physiology and Zoology; Vegetable Physiology and Botany
SPECIFICATIONS.

-W. C. Williamson, F.R.S. Improvements in the manufacture of alkaline sulphates. J.C. Geology and Palæontology-W. Boyd Dawkins, M.A., F.R.S., F.G.S.

Physiology and Histology-Arthur Gamgee, M.D., F.R.S. Stevenson, South Shields, Durham, May 8, 1875:-No. 1723. This Mineralogy-C. A. Burghardt, Ph.D. invention relates to the preparation of common salt to be used in the Oriental Languages; German-T. Theodores. process patented by Messrs. Hargreaves and Robinson for the manu. French Language and Literature-J. F. H. Lallemand, B. és Sc. facture of sulphate of soda by exposing common salt to the action of Free-Hand Drawing-William Walker. sulphurous acid.

Harmony and Musical Composition-Edward Hecht. Improvements in the treatment of natural substances containing With Assistant Lecturers in all the Principal Departments. phosphates of alumina. M. Prentice, Stowmark:t, Suffolk. May 11, 1875:- No. 1758. This invention relates to the treatment of natural

The NEXT SESSION will COMMENCE on the 3rd of OCTOBER.

Candidates for Admission must not be under fourteen years of age, products containing phosphoric acid and alumina, and consists in subjecting such natural phosphates to the action of an aikali or alkaline

and those under sixteen will be required to pass a Preliminary Excarbonate, such, for example, as caustic soda, or carbonate of soda, or

amination in English, Arithmetic, and the Elements of Latin. soda-ash, or to what is known as black-ash liquor, or to other alkaline Medicine, the Evening Classes, and of Scholarships and Entrance

Prospectuses of the several Departments of Arts, Science and Law, works, in order that the phosphoric acid and the alumina contained in Exhibitions, will be forwarded on application. the natural phosphates may be separated therefrom by being thus ren.

J. HOLME NICHOLSON, Registrar.

OWENS

21.

ON A

,}

The Oil of Wood. Sept 1, 1876.

85

bismuth or 2} of subnitrate with 7 parts of crystalline THE CHEMICAL NEWS. hyposulphite.

The solution of the potassic salt is placed in a small

flask, the bismuth solution is added, then the hyposulphite, VOL. XXXIV. No. 875.

the whole is mixed rapidly, and 200 to 250 c.c. of concentrated alcohol are added. The whole is agitated for a few moments, and left to settle. The yellow precipitate collects at the bottom of the flask, and may be filtered after

a quarter of an hour, and carefully washed with alcohol. NEW PROCESS FOR THE QUALITATIVE The precipitate cannot be weighed; it is dissolved upon

the filter in excess of water; the bismuth is thrown down DETECTION AND THE DETERMINATION

as sulphide by sulphydrate of ammonia, washed by decanOF POTASSA.

tation, collected on a tared filter, dried at 100°, and By M. A. CARNOT.

weighed. The weight obtained may be corrected by separating from the filter a part of the dried precipitate, and

heating it again to 150° to 200° in a small platinum In spite of the improvements in the estimation of potassa crucible, weighing before and after, and correcting the introduced by Peligot and Schlesing, its exact determina- total weight of the sulphide accordingly. The weight of tion in a somewhat complex substance remains one of the the potassa is found on multiplying the weight of the most delicate operations in analytical chemistry. We sulphide of bismuth found byhave, further, no reagent sensitive enough to detect its

3KO presence in small quantities.

=0549 The new reaction of the salts of potassa in presence of

Bi2S3 hyposulphite of soda and a salt of bismuth in a solution The method has been found accurate in presence of mixed with alcohol solves both these difficulties.

soda, lithia, ammonia, lime, magnesia, alumina, and iron. We dissolve in a few drops of hydrochloric acid 1 part -Comptes Rendus. of the subnitrate of bismuth-say half a grm.-and, on the other hand, about 2 parts (1 grm. to 11) of crystallised hyposulphite of soda in a few c.c. of water. The second solution is then poured into the first, and concentrated NOTICE ON THE OIL OF WOOD. alcohol is added in large excess. This mixture is the re

By M. GUIBOURT. agent.

If brought in contact with a few drops of the solution of a potash-salt it at once gives a yellow precipitate. With This curious product of India, called by the English an undissolved potassic salt it produces a decidedly yellow wood-oil or Gurjun balsam, forms already the subject of colouration, easily recognised.

two papers published in the Pharmaceutical Fournal, All potassic salts with mineral acids are equally by Messrs. Charles Lowe and Daniel Hanbury. Mr. susceptible of this reaction, sulphates and phosphates as

C. Lowe, who only knew that this resinous liquid is well as nitrates, carbonates, chlorides, &c. It is also very extracted in India, by incisions made in the tree, considers sensitive with the organic salts, tartrates, citrates, &c.

it as a Copaiva balsam rendered turbid by a greenish The reaction is not interfered with by the presence of resin held in suspension. The filtered balsam forms a other bases with which nothing analogous is produced. brown and transparent liquid, from which we withdraw by The character is, therefore, perfectly distinct.

distillation, Baryta and strontia alone may occasion some difficulty,

Volatile oil.. by reason of the white precipitates of double hyposulphites

Hard resin..

34 which they form with the same reagent; but it is very

Water and acetic acid rare to meet them along with potassa, and they are very easily detected and removed.

According to Mr. Lowe the volatile oil possesses all the If we have a solution containing merely a few milligrms. characters of that of copaiva, and the hard resin, which ot potassa, it is reduced by evaporation to a very small he regards as pure copaivic acid, free from the soft resin, volume, or even to dryness, when the characteristic re- which, according to him, exists in the most part of com: action readily appears. Or slips of filter-paper may be mercial copaivas, seemed to him to indicate a superior repeatedly saturated with the dilute solution, and after quality as a medicine. I avow that I scarcely understand drying be steeped in the alcoholic reagent, when the yellow this conclusion, and that I am so much the less convinced colour will appear, especially on the margins of the paper. of the identity of the hard resin with copaivic acid as Mr.

The author's quantitative experiments refer chiefly to Lowe has observed in the new resinous balsam the singular nitrates, chiorides, and mixtures of the two salts. With property of solidifying when exposed, in a closed vessel, some special precautions the method may probably be to a temperature of 230° F.; copaiva presents nothing applied direaly to sulphates, though these are easily con- similar. i find further this difference, that the new balsam verted into chlorides by chloride of barium, removing the distilled with an addition of a little quantity of an excess of baryta with sodic or ammonic carbonate. oxidising body as chlorine, hypochlorite of lime, or

The hyposulphite of commerce is sufficiently pure for bichromate of potash, furnishes an essence of a beautiful use; the crystals are dissolved in a small quantity of blue colour, whilst common copaiva with soft resin water at the moment of the experiment.

scarcely furnishes any coloured essence. The notice conThe chloride of bismuth is prepared by treating the cludes with a mention of a falsification which appeared to pulverised metal with a few drops of nitric acid, evaporating me at once ill-founded and little to be feared; it is that io dryness, and then heating with a very small quantity of cold sulphuric acid produces with copaiva a purple colourahydrochloric acid. The lead possibly present in the tion like that obtained with cod-liver oil, to such an extent bismuth is got rid of by adding to the cold solution con- that dishonest persons might sell a mixture of olive oil or centrated alcohol, which causes chloride of lead to be any other fatty oil with a little quantity of copaiva for deposited. Or subnitrate of bismuth may be dissolved in cod-liver oil. Mr. D. Hanbury tells us in his notice that a few drops of hydrochloric acid.

oil of wood is extracted from Dipterocarpus turbinatus by The liquid in which the potassa is to be determined quite a pe-uliar process, which I shall describe in a few should not exceed 10 to 15 c.c. in bulk, so that the entire words, in order to make the nature of the product better volume of the aqueous solutions may not exceed 20 to 25 known. To obtain it a large incision is made in the c.c. For i part of supposed potassa we take 2 parts of trunk of the tree, about 30 inches from the ground, upon

65

I

86
Development of the Chemical Arts.

CHEMICAL News,.

Sept. I, 1876. which they kindle and maintain a fire so that the incision colour of the red does not then appear, but it becomes may be charred; soon after the liquid begins to run. It manifest when, after agitation, a thin layer of the liquid is conducted by means of a little gutter, into a vessel covers the upper side of the bottle. Then in whatever destined to receive it. The average yield of the best manner we look at this layer there appears a beautiful trees during a season is from 30 gallons, &c. Roxburgh green colour. The same green colour appears again and adds that oil of wood is also produced by the Diptero becomes permanent when, after having dissolved the woodcarpus incarnus, alatus, and costatus. The first is reputed oil in alcohol, we leave the liquid to spontaneous evaporato furnish the best sort and in the largest quantity. Oil tion; we then see towards the top of the capsule, between of wood, which makes the object of Mr. Hanbury's notice, the parts of green resin, white radiating tufts belonging to has been imported in a large quantity from Moulmein, in a particular principle of which I leave the examination to British Burmah. When filtered it forms a transparent those who have a larger quantity of the material at their liquid of a very deep brown by transmitted light, but it disposal. As for the resin it has acquired a permanent scems opaque and of an obscure green when seen by re- green colour, which we find in a dry resin which remains flection. It possesses then in a very marked degree the when we boil wood-oil and water for a very long time. dichroism obverved in all resinous oils obtained by fire. This green colour which is also that of the beautiful resin I insist on this character, which settles the nature of the of Piney (Vateria indica) which was seen in the Exhibition, wood-oil, which is not simply a natural product like establishes a point of comparison between two products copaiva, but which results, in part at least, from a liquid which come from trees belonging to the same family, the modification of the resin of Dipterocarpus obtained by the Dipterocarpeæ; but the resemblance stops there, for the action of fire. This oil of wood from Moulmein is more resin of the Vateria indica is insoluble in alcohol and very consistent than olive oil; it weighs o‘964, and possesses imperfeAly soluble in ether, whilst the green resin of the an odoar and a taste very analogous to copaiva. It wood-oil is easily soluble in these two mediums. Finally, dissolves in twice its own weight of absolute alcohol, with the wood-oil derived from the Exhibition behaves like the exception of a little quantity of matter which is sepa copaiva with ammonia and calcined magnesia. It is rated on standing. But the most curious property of this solidified very promptly with 1-16th of calcined magnesia, oil, already noticed by Mr. Lowe and observed anew by and its mixture with ammonia becomes again liquid and Mr. Hanbury, is that it solidifies when heated in a tolerably transparent after a momentary opacity. I am stoppered vial at 266° F.; at this temperature the oil far from concluding with Mr. Lowe that the two oleo. becomes turbid and so gelatinous that it is not displaced by resinous bodies are chemically identical; but with regard the inversion of the vessel. After cooling the solidifica | to their medical uses I think that all the turpentines and tion becomes more complete; but a gentle heat aided by balsams, liquids or even solids, can be useful as remedies a slight agitation re-establishes its former fluidity. Mr. for the catarrhal state of the mucous membranes. I conLowe had indicated the temperature of 230° F. for the clude by saying that the wood-oil of Mr. Hanbury and solidification of wood-oil. I suppose that the difference that derived from the Exhibition have not probably been of temperature pointed out by the two observers depends extracted by the same method. The first has been obon that of the liquids upon which they have operated ; for tained by the aid of fire, by the process described by just as the copaiva furnished by various copahifera of Roxburgh; ths second has, without doubt, been obtained America, or the turpentines produced by the different without the intervention of this agent, for I do not find species of pines and firs, are not identical, it is very reason. the characteristic features of oils which result from the able to think that the oils of wood furnished by Diptero- action of fire on resin.-Journal de Pharmacie et de carpus turbinatus, incarnus, alatus, costatus, &c., are not Chimie. absolutely alike; the higher or lower temperature which the oil has undergone may be also a cause of variation in

REPORT the properties of the product. What I say here is not a supposition; it is a fact at present certain. In the Universal Exhibition of 1855, there were two samples of DEVELOPMENT OF THE CHEMICAL ARTS wood-oil, one coming from Canara the other from Tenas

DURING THE LAST TEN YEARS.* One of these samples, I do not know which, contained in a little pot of white earthenware which, of an

By Dr. A. W. HOFMANN. intermediate grade between stoneware and porcelain, had

(Continued from p. 78.) been given by Dr. Royle to M. Delasse, a member of the International Jury, charged to give a report on the bitumens and petroleums admitted to the Exhibition.

Chlorine, Bromine, Iodine, and Fluorine. M. Delasse, not finding there what he sought, sent back

By Dr. E. Mylius, of Ludwigshafen. the sample, which I judged in consequence ought to be For the latter purpose Kunheim utilises the chlorine the new copaiva announced by Mr. Lowe. It approxi- obtained on Deacon's method. The chlorine is here so mates, in fact, much more to the balsam examined by Mr. completely absorbed by the milk of lime through which it Lowe than to that for which I am obliged to Mr. Hanbury. passes that mere traces are contained in the air escaping The wood-oil of Mr. Hanbury has nearly the liquidity of from the exhauster. The draft in the entire apparatus is olive oils; if placed between the eye and the sun it is kept up by any aspiratory arrangement beyond the completely transparent and of the colour of dark Malaga chloride of lime chambers and measured by an anemowine; by reflection it seems opaque and of an olive green. meter constructed by Hurter. The latter consists of a It behaves with ammonia and magnesia in a very different U-tube of 5-16ths c.m. internal diameter, with legs about manner from copaiva. Mixed with liquid ammonia at 25 c.m. in length. As one leg of this tube is always in 22° B., in the proportion by weight of 5 parts of balsam communication with the gaseous current, the pressure to 2 of alkali, it forms immediately an opaque and very occasioned by the current is always shown in the other thick mixture which does not change by time. It is not leg by the tube by the displacement of a liquid therein solidified by 1-16th of calcined magnesia; the two sub-contained (ether). The U.tube is fixed so that the leg stances separate on standing. The wood-oil of M. containing the liquid lies flat on a graduated inclined Delasse has the aspect of a thick and slightly gelatinous plane, which may be raised or lowered on a frame fitted liquid. After having deposited a little green resin, which with a level. The meniscus of the liquid is thus extended is held in suspension, it becomes almost transparent; if diagonally, and the small vertical divisions of the scale placed between the eye and the sun it is of a very deep are magnified into long contal degrees. Kunheim red; if seen by reflection it appears still red but turbid, uses a simple upright U-tube filled with ether. and resembles a liquid in which fine powder of cochineal * "Berichte über die Entwickelung der Chemischen Industrie has been suspended by agitation. The complementary i Während des Letzten Jahrzehends."

ON THE

serim.

« PoprzedniaDalej »