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Sodium amalgam with water shows | soluble in ammoniacal tartrate. +32.6 cals., and potassium amalgam +270 cals. per equivalent of metal dissolved. With hydrochloric acid so diluted that I equiv. = 2 litres the results were for sodium +46'5, and for potassium +412 cals. The alkaline amalgams in hydrogenising reactions always disengage more heat than does free hydrogen. This thermic excess explains the hydrogenising power of amalgams, and throws a light upon the general theory of the reactions formerly ascribed to the nascent state.

precipitated, and generally very completely, by potassic ferrocyanide, whilst those of the latter group remain perfectly dissolved in the basic ammonic tartrate.

Stanno-propyls and Iso-stanno-propyls.-MM. A. Cahours and E. Demarçay. The use of an alloy containing less than 10 per cent of sodium yields a mixture of the diniodide of distanno-propyl and of the moniodide of tristanno-propyl, the separation of which is scarcely possible. To obtain the former of these compounds pure the product of the reaction of propyl-iodide upon tin must not be distilled except in a vacuum. Its composition is represented by Sn2(C6H7)212. The iodide of tristannopropyl is Sn2(C6H7)3I. The properties of these compounds are described at length.

Quantity of Nitric Acid Contained in the Water of the Nile before and after its Rise.-M. d'Abbadie. -The quantities of nitric acid per litre of water before, during, and after the floods are represented as being o'or, 0'0038, and o'002 grm.

Origin of Sound in the Telephone.-Th. du Moncel. -It is certain that the induction currents produced by a Bell's telephone can occasion the reproduction of speech in a magnetic disk surrounded with a helix without any need for a diaphragm influenced by such disk.

Rays of the Vapour of Sodium.-Mr. N. Lockyer. New Arrangement for Increasing the Sensibility of the Vibrating Plate of the Telephone.-M. C. Decharme. The author proposes to fix such plates by their centre only.

A Compound of Alumina and Carbonic Acid.MM. Urbain and Renoul.-If alumina is precipitated from alum by means of sodic carbonate two bodies are obtained differing in aspect according as the liquid was boiling or of the common temperature of the atmosphere. In the former case the precipitate is gelatinous, transparent, and filters slowly, whilst in the latter case it is opaque, separates readily from the liquid, and absorbs colouring matters much more abundantly than the transparent variety. The author finds that the opaque variety contains carbonic acid in such proportions that it may be represented by the formula, CO2,2Al2O3,8HO.

Mr. Lawrence Smith remarked that a natural carbonate of alumina and soda existed at Montreal.

Bulletin de la Société Chimique de Paris,
No. 10, May 20, 1879.

Oxy-ferrocyanide of Ammoniacal Copper.-Antony Guyard. The precipitate obtained by adding potassic ferrocyanide to ammoniacal sulphate of copper if washed and dried in the air at about 150° loses cyanogen and ammonia, absorbs oxygen, and takes a violet tone. The material should be spread out in a thin layer, and stirred continually till the heat reaches 170°, when the reaction is complete. The colour does not seem available either in painting or in the pigment style in calico-printing. If heated up to 200° the colour changes to a blue, and at from 240° to 250° to a green, neither of them remarkable for brightness.

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Volumetro-Chemical Studies.-W. Ostwald.-The contractions or dilatations experienced on mixing the solutions of salts may serve for the measurement of their respective affinities, and have furnished the author with results analogous to those obtained with the calorimeter by M. Berthelot and M. Thomsen.

Atti della R. Accademia dei Lincei.
Fasc. 4, March 1879.

Researches on Cinchonin.-Prof. Filetti. - The

author dissolved 15 grms. cinchonin in a slight excess of hydrochloric acid, diluted the solution to 4 litres, saturated it with chlorine, and exposed it to the direct action of light. A white or slightly yellow substance was deposited on the sides of the beaker. This deposit dissolves in glacial acetic acid, and is re-precipitated by water. On heating cinchonin with bromine and water for several days in a closed tube he obtained products, the examination of which is still incomplete.

Verhandlungen des Vereins zur Beforderung des
Gewerbfleisses. April, 1879.

This number contains no chemico-technological matter.

MISCELLANEOUS.

The Royal Society.-On Thursday, the 12th inst., the following fifteen candidates were elected Fellows of the Royal Society:-J. Anderson, M.D., Rev. M. J. Berkeley, H. Bessemer, Prof. A. Crum-Brown, W, L. Buller, Sc.D., G. H. Darwin, Prof. J. D. Everett, Prof. F. S. B. François de Chaumont, Prof. G. D. Liveing, G. Seeley, B. Williamson, and T. Wright, M.D. Matthey, G. J. Romanes, A. Schuster, Ph.D., Prof. H. G. The following have been elected Foreign Members of the Society-Arthur Auwers, Berlin; Luigi Cremona, Rome; Jean Louis Armand de Quatrefages, Paris; Georg Hermann Quinke, Heidelberg; Theodor Schwann, Liege; Jean Servais Stas, Brussels.

NOTES AND QUERIES.

Liquid Perchloride of Iron.-I should be glad if any of your correspondents could tell me where there is a good market for liquid perchloride of iron in quantities (sp. gr. 1'400), and the price that would be given. Also protochloride of iron (sp. gr. 1'400°). Have convenience for making large quantities.-SCARLET.

MEETINGS FOR THE WEEK.

MONDAY, 23rd.-Royal Geographical, 8.30.
WEDNESDAY, 25th.-Society of Arts, 4. (Anniversary.)
TUESDAY, 24th.-Anthropological, 8.

Geological, 8.
THURSDAY, 26th.-Royal Society Club, 6.30. (Anniversary.)
FRIDAY, 27th.-Quekett, 8.
SATURDAY, 28th.-Physical, 3.

THE YORKSHIRE COLLEGE.

"he Worshipful Company of Clothworkers of

The

the City of London having increased their Endowment of the Textile Industry Department of the College so as to include instruction in Dyeing, the Council of the College is prepared to receive the Fees. Preference will be given to Candidates who are familiar with the processes of French and German Dyeing and with the Methods of Instruction pursued in the Continental Schools. Applications, accompanied by a statement of the Candidate's experience, together with copies of Testimonials, to be sent not later than August 11th to the Secretary of the Yorkshire College, from whom further information may be obtained. The work of instruction wil begin in January, 1880.

A Law Peculiar to the Metallic Ferrocyanides.applications for the post of Instructor; Stipend, £300 a year and half Antony Guyard.-The hydrated oxides, as existing in their soluble salts, may be divided into two great groups according to their behaviour with aqueous ammonia :Ist. Oxides soluble in ammonia and in ammoniuretted ammoniacal salts, including, of course, the tartrate. 2nd. Oxides insoluble, or very sparingly soluble, in ammoniuretted ammoniacal salts, but, on the other hand,

Leeds, June 18th, 1879.

W. F. HUSBAND, Secretary.

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Analytical Chemist desires an appointment.

Would be willing to make himself useful in any capacity; London preferred.-Address, Chemist, 351, Middleton Road, Oldham.

CHEMICAL NEWS,
June 20, 1879.

London 18th June 1879 NOTICE-ARTIFICIAL ALIZARINE

A German Chemist (Ph.D.), holding diplomas WE the undersigned the Owners respectively

from University and Polytechnicum, who has already had experience in a manufactory, seeks a Situation in a Chemical Manufactory in England.-Address, K.D., CHEMICAL NEWS Office, Boy Court, Ludgate Hill, London, E C.

of the Patents for the Manufacture of Alizarine

AD 1869
AD 1869
AD 1869

No. 1936
No. 1948
No. 3318

HEREBY GIVE NOTICE That we recently commenced Legal

Required by an Associate of the Royal School Proceedings against The Alizarine and Anthracene Company Limited

Mines, F.C.S., &c., a Situation in a Laboratory, or as Manager of a Chemical or Metallurgical Works, or on a Mine, in England or abroad. Highest references-Address, A.R.S.M., CHEMICAL NEWS Office, Boy Court, Ludgate Hill, London, E.C.

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for damages for the infringement of the above-mentioned Patents and for an Injunction to restrain the said Alizarine and Anthracene Company Limited from manufacturing selling or from offering for sale or disposing of or parting with any Artificial Alizarine or other Coloring Matters manufactured or prepared in contravention of our rights under the said Patents or either of them respectively And that after obtaining an interim injunétion on the terms of out appli

FOR SALE. About 150 tons Monthly of cation we at the request of the said Alizarine and Anthracene Com

Woollen Shoddy; free from grease; containing nitrogen equal to from 5 to 10 per cent ammonia.-Apply to David Shaw and Co., Clayton, near Manchester.

Superior Iron Filter-Press for Sale, made to

order and of extra quality, by Messrs. Needham and Kite. It contains ten chambers, each 19×21 inches; is provided with a 3-inch gun-metal pump to work by hand or steam, and with fittings for washing and steaming, which can be used or not at discretion. The whole is quite equal to new, and is in perfect working order.-Address L. B. S., CHEMICAL NEWS Office, Boy Court, Ludgate Hill, London, E.C.

- Wanted two for Creosote; secondhand if in good condition -Full particulars to be addressed"Tank," CHEMICAL NEWS Office, Boy Court, Ludgate Hill, London, E.C.

TANK WAGGONS.

pany Limited agreed to stay our Action upon the following terms
a. That the said Alizarine and Anthracene Company Limited
should submit to a perpetual Injunction

b. That they should admit the validity of the said Patents
c. That they should pay damages for past infringements
d. That they should pay our Costs of the Legal Proceedings
A perpetual injunction against the Alizarine and Anthracene Com.
pany Limited have been granted and all proceedings in the Action
have been stayed on the above terms

AND WE HEREBY GIVE FURTHER NOTICE that we recently were about to institute legal proceedings against MessrB. Arthur and Henshaw Drysalters and Oil Merchants in Glasgow and Matthew Clark and William Andrew Jamieson Drysalters and Oil Merchants Glasgow the individual partners of the said firm of Arthur and Henshaw to obtain interdict against their infringing the said Letters Patent or any of them and damages for infringements thereof by them in time past and that we have agreed to discontinue and discharge the said threatened proceeedings upon certain conditions embodied in an Agreement entered into between us and them Under

A Part or the Whole of Excellent Laboratory the said Agreement the said Messrs. Arthur and Henshaw and the

Fittings to be Sold with the Lease of an Eligible DwellingHouse. Rent very moderate.-Further particulars of E. and S. Smith, Auctioneers and Agents, 22, Southampton Buildings, Chancery Lane, W.C.

DAVID

HILL, CONSULTING CHEMIST

in

Technical Processes, late of Deans Terrace, South Shields. Letters to be addressed care of Messrs. Bulloch and Co., 79, Mark Lane, London, E.C. Special attention given to questions relating to "Noxious Vapours."

WILLOUGHBY BROS., CENTRAL FOUNDRY,

PLYMOUTH, Makers of Plant for Sulphuric Acid and Superphosphate Works, also for Tar and Ammonia Distilling.

NORRINGTON'S PATENT,

For the prevention of escape of gases during the charging of kilns and nitre pots. The success of this invention being assured, we are

prepared to Contract for fixing this Patent Apparatus to Pyrites Furnaces throughout the Kingdom.

Estimates and Plans furnished on application.

Silicates of Soda and Potash in the state of

Soluble glass, or in CONCENTRATED SOLUTION of first quality, suited for the manufacture of Seap and other purposes, upplied on best terms by W. GOSSAGE and Sons, Soap Works, Widnes, Lancashire.

London Agents, COSTE and Co., 19 and 20, Water Lane, Tower Street, E.C., who hold stock ready for delivery.

TO PROFESSORS & EXPERIMENTALISTS.

W STONE, Mathematical, Surveying, and

Square, Bloomsbury, works out all kinds of difficult experimental and scientific work.

S. A. SADLER,

said Matthew Clark and William Andrew Jamieson the individual
partners of the said firm admit and acknowledge

a. That the said Letters Patent are valid in every respect
b. That they have infringed the said Letters Patent by importing
vending and selling Artificial Alizarine manufactured ac-
cording to one or other of the processes described in the
Specifications respectively filed in connection with the said
Letters Patent

c. That the Letters Patent of the 28th May 1869 No. 1642 granted
to Franz Julius Brönner (therein named Julius Brönner)
and Hermann Gutzkow are and always have been null and
void

d. They undertake during the subsistence of our said Letters Patent not to import into or sell within the United Kingdom any Artificial Alizarine produced by any of the processes described in the Specifications of any of our sald Letters Patent except with our consent in writing WE LASTLY GIVE NOTICE that any person or persons infringing our above-mentioned Patents whether by purchasing (except from us or our Licensees) or selling importing or being concerned in importing or in anyway using Artificial Alizarine in the United Kingdom other than Alizarine made here by us or imported by us or our Licensees will be immediately proceeded against

A REWARD will be given to any person who will give the undersigned information sufficient to undertake legal proceedings against any such Infringers

BURT BOULTON and HAYWOOD 64 Cannon Street City London Badische Anilin and Soda Fabrik F. ENGELHORN AUGUST CLEMM MINERALOGY AND GEOLOGY. NEW LIST of Collections of Minerals, Fossils, and Rocks, with prices. New List of Minerals for Chemical Purposes, Manufactures, and Research. New List of Varieties of Rocks. New List of Prices and Sizes of Cabinets for Natural History and other purposes. New Catalogue of Secondhand and New Books on Geology and Kindred Sciences. New Supplementary List of Books. New List of Sections of Rocks and Minerals for the Microscope. New List of Prices and Patterns for Geological Hammers. New List of Blowpipe Cabinets, Apparatus, and Materials. Also Implements and Appliances for

CLEVELAND CHEMICAL WORKS, practical work in Geology and Mineralogy.

MIDDLESBROUGH;

Newfall Tar Works, Carlton;
Ammonia Works, Stockton-on-Tees;
and Stamshaw Chemical Works, Portsmouth.
And also of the Furness Tar Products Co., Ulverston.

Manufacturer of Benzole, Toluole, Xylol,

Solvent and Burning Naphthas, Carbolic Acid and Disinfecting Powder, Refined Anthracene Naphthaline, Black Varnish, Refined Tar, Crude Liquid Ammonia, Coal-Tar, Pitch, Creosote, Grease, Sulphate of Ammonia, Pyroligneous Acid, Acetate of Lime, Wood Naphtha, Charcoal, &c., &c.

S.A. S. is always a buyer of Coal-Tar Naphthas, Crude Anthracene

nd all Tar Products.

All communications to be addressed to the offices at Middlesbrough.

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In the ordinary method of Manufacture, at the time of charging the Kilns, a considerable escape of gases takes place. This is attended with proportionate loss of Sulphur, and with much inconvenience to the workmen, as well as annoyance to the vicinity of the Works. This may be entirely avoided by the adoption of C. Norrington's patented invention, which can be applied at moderate cost to existing Plant, as well as in the erection of new Works. It may be seen in full operation on extensiv e Plant at Messrs. C. Norrington and Co.'s Chemical and Manur e Works, Cattedown, Plymouth, where the fullest information may be obtained, with terms for cense.

THE CHEMICAL NEWS. make this preliminary communication, since, from a paper

VOL. XXXIX. No. 1022.

ON THE

LIMITED OXIDATION OF THE ESSENTIAL OILS.

PART V.

THE ATMOSPHERIC OXIDATION OF TURPENTINE. By C. T. KINGZETT.

1. In my previous papers, which were communicated to the Chemical Society and the British Association, I have shown that when the so-called essential oils are exposed to atmospheric oxidation, peroxide of hydrogen is produced in an indirect manner. In the case of turpentine, which was more particularly studied, it seemed to me that a camphoric peroxide (C10H1404) is first formed, and that this is slowly decomposed by the action of water, yielding peroxide of hydrogen and camphoric acid, thus

C10H1404+2H2O=C10H1604+H2O2

Certain it is that I obtained camphoric acid in my experiments, and analysed some of its compounds. I also succeeded in showing that all hydrocarbons of the formula C10H16 (terpenes) similarly give rise to the formation of peroxide of hydrogen, and that this property is shared by menthene, CroH18. On the other hand, it was observed that the hydrocarbons of the formula C15H24 did not behave in this way. The production of peroxide of hydrogen by the atmospheric oxidation of the specified hydrocarbons seemed to have some kind of connection with another property of the same bodies. It had been shown by Oppenheim and Wright that all the terpenes yield cymene (C10H14) when subjected to suitable processes, and, moreover, it appears that cymene as obtained from all sources is identical. According to Fittica, cymene is normal propyl-methyl-benzene, in which the methyl and propyl occupy the para position. This view has not received universal acceptance, but whatever it may be worth, there is apparently no satisfactory reason for doubting the identity of cymene prepared from different compounds, and the researches of Paterno lend particular

confirmation to this statement.

Now, since all the terpenes and menthene give peroxide of hydrogen as above stated, and since they also contain a cymene nucleus, the two facts seem to be related, and this relation is confirmed by my observations, that cymene itself yields peroxide of hydrogen also, while the hydrocarbon from oil of cloves, C15H24 (Church), does not yield peroxide of hydrogen and (as I anticipated would be the case) does not yield cymene by bromination (as shown by Wright).

In the last part of my research the general features presented in the atmospheric oxidation of turpentine on a large scale were described in detail, and it was then shown that the compound which is primarily formed, and which afterwards (viz., when in contact with water) gives rise to the formation of peroxide of hydrogen, may be obtained in such amount that when the oil of turpentine containing it is subjected to distillation decomposition occurs just above the boiling-point with almost explosive violence. As is well known, the atmospheric oxidation of turpentine is now conducted as a commercial operation (for producing the disinfectant called "Sanitas"), and I have been naturally anxious to continue my experiments in order to obtain a more perfect knowledge of the process and its products. Unfortunately, the performance of other duties has largely

Part I.-Journal of the Chemical Society, June, 1874. Part II.Ibid., March, 1875. Part III-CHEMICAL NEWS, vol. xxxii., p. 13. Part IV.-Ibid., vol. xxxiv., p. 127.

interrupted my work, and even now I am only induced to read at the last meeting of the Chemical Society, I perceive that Dr. Armstrong is working in some measure upon the same subject.

Having said so much, I will now give the notes of my recent experiments, all of which I intend to repeat and work out to their final conclusions as opportunity may offer and time permit.

2. There is a great difference presented by different essential oils, and even by various kinds of turpentine, as regards the rate at which they individually absorb oxygen from the air; and not only is this the case, but an oil of turpentine which, say, absorbs oxygen at a given rate, will absorb it much less rapidly if freed from contained oxidised matters by distillation. In other words, when once the process has begun, it continues more and increasingly rapidly, so that the greater the amount of oxidised matter contained in the oil the greater the oxidation under given conditions. The following table is interesting as illustrating the relative absorptive rates for atmospheric oxygen presented by the various oils experimented with. The method employed was as follows:A number of very long tubes (made from combustion tubing) and sealed at one end, were charged with equal volumes of air, water, and the various oils. After exposure to sunlight of summer for a number of hours, and before all the oxygen was absorbed in any case, the tubes were removed to the laboratory and the residual gas in each tube measured. Calling the largest amount of oxygen absorbed 100, then

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The oils a, b, d, and e were undoubtedly genuine commercial oils; the oil c was perhaps French oil of turpentine, and in this case only was the oil distilled before use, because to my knowledge it had undergone great oxidation by keeping for many years; the oils ƒ and g were evidently not genuine, and had been sent to me merely as samples; I should say that both had been adulterated that when the oils which absorbed atmospheric oxygen at with so-called pine oil of commerce. It may be mentioned the relative rates indicated by 100, 100, 78.9, and 75 were taken in equal amounts and placed in cylindrical glasses having their tops covered with paper treated with the same amount of the same mixture of potassic iodide and starch, the papers became coloured owing to the formation of peroxide of hydrogen in their vicinity in the same order. The same general result has been obtained in oxidising very large quantities of the same oils for commercial purposes.

3. In Parts II. and IV. I have described the general nature and characters of the aqueous solution which is obtained when oil of turpentine is, in the presence of water, exposed to the action of a blast of air, and it is therefore unnecessary to do the same thing again in this place. If this solution be evaporated on the water-bath to dryness, of course all the acetic acid is got rid of, and mains behind a dark coloured matter, which when hot all the peroxide of hydrogen is decomposed. There rehas a sugar-like odour and is viscid; on cooling it sets into an adhesive but firm mass, which, when treated with what resembling that bearing Pettenkofer's name. concentrated sulphuric acid, gives a colour reaction some

of the substance was dried at 100° C., and burnt with To get some sort of knowledge of its composition a part

The weight did not become constant, the substance being evidently slowly volatile at 100° C. After being in the oven for forty or fifty hours the residual substance lost 10 per cent during the next forty hours.

280

Limited Oxidation of the Essential Oils.

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of the solution.

When the substance whose analysis has been given above is heated with water it is found to be imperfectly soluble: roughly, about 5 per cent remains as a viscid, insoluble, nearly black matter. In one experiment, working with nearly half a pound of substance, this separation was effected, and for the time being the insoluble matter was set on one side. The yellowish brown solution was shaken with purified animal charcoal, but this failed to remove any of the colour, although the charcoal abstracted a considerable amount of the substance itself. The solution was finally evaporated to dryness, and there was thus obtained a transparent varnish-like substance, of an agreeable odour, and showing itself to be volatile when heated in the air-bath at 100° C. It was analysed, observing the same precautions as before, but the manipulation of the substance was very difficult, owing to its semi-fluid state when hot, and its adhesive nature in the cold. 02884 grm. gave 0'263 grm. H2O and o'6688 grm. CO2. These figures give

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I believe that in this analysis the carbon came out a little too low on account of the difficulty just mentioned, but practically it may be said that the removal of more than 5 per cent of matter from the originally analysed substance did not materially affect its composition. It will be convenient here to speak of that part of the residue soluble in water as the soluble part, and that which is left undissolved by water as the insoluble part.

The insoluble part does not give the vivid reaction with strong sulphuric acid that is afforded by the other part, and even when a drop of strong sugar solution is added but little purple colour is obtained. Although insoluble in water it readily dissolves in an oily matter (to be hereafterwards described) which accompanies it and the other substance in the original solution; hence its insolubility is explained.

CHEMICAL NEWS,
June 27, 1879.

process more carefully with a view to determine the temperatures at which the different products came over; neither have I yet examined, analytically or otherwise, either the crystalline matter or the liquid oils.

Again, if the body whose analytical numbers agree with the formula C10H1803 be dissolved in water, and the solution acidified with dilute sulphuric acid, it grows milkyand on standing a slightly coloured oily body of consider, able quantity separates. This reaction will probably lead constitution of the substance C10H1803; and indeed I have on further examination to a better understanding of the of its change there will be obtained very important evino doubt that with a knowledge of this and the products dence as regards the nature and constitution of the ter

penes as a class.

obtained by oxidising Russian turpentine in the presence 5. Several litres of the aqueous solution ("Sanitas"), of water, were treated with caustic soda in bare excess, of neutralisation, was evaporated nearly to dryness on the and the mixture, which darkened very much at the point water-bath. The dark-coloured soft resin-like residue thus obtained was then treated with an excess of dilute sulphuric acid. By this treatment there separated a dark oily mass, from which the clear solution was filtered, and then subjected to distillation. As the acid solution became hot more oil separated out, and there passed over an acid distillate accompanied by 20 or 30 c.c. of a slightly yellow volatile oil, with an odour resembling that of mixed cymene and eucalyptus. This oil, which gives a beautiful colour-reaction with strong sulphuric acid, is probably identical with that obtained in (4) by treatment of the CoH103 substance with dilute sulphuric acid. At the end of the distillation there remained in the retort a quar tity of black tarry matter floating in a fluid state on the surface, and on cooling it set into a thick skin. The acid distillate was separated from the oil, and then exactly neutralised with pure caustic soda, and the solution evaporated to the point of crystallisation. In this way crystals of sodic acetate were obtained, and subsequently pure acetic acid and its other salts were made. The acetic acid obtained did not amount to more than o'25 grm. per litre of fluid operated upon; nevertheless, this observation confirms similar facts which I stated in the second part of this research. I could detect no other volatile acid.

If the aqueous solution which formed the subject of this last experiment be distilled alone, a certain amount of oil also passes over with the distillate. For instance, in one experiment 1000 c.c. fluid yielded about 5 c.c. of oil. More than double the amount, however, is obtained if the solution be acidified with sulphuric acid. Whether, however, these oily distillates are identical in composition cannot yet be stated, nor am I as yet assured that no other volatile matter soluble in water also passes over.

6. I have now sufficiently indicated the work that has lately occupied my attention, and I may add that I anticipate its further prosecution will be attended with very interesting and important results. This is particularly the case, since in my process of oxidation there is no violent change like that resulting from the use, for example, of nitric acid, and hence the products are much more nearly to and comparable with the original terpene employed: as a consequence the results are more intelligible, and the inferences to be drawn from them acceptable accordingly.

The soluble part, C10H1803 (?), gives with strong sulphuric acid a deep cherry-red colour reaction, and this is not intensified by adding syrup. When heated on platinum-related foil it melts, evolves inflammable gas, and leaves a charcoal. Its aqueous solution reduces Fehling's solution just as glucose does, and exhibits very powerful antiseptic characters.

4. A quantity of this substance was subjected to distillation. At first it melted, then boiled, and a small quantity of an almost colourless oil passed over, which condensed into a colourless, soft, crystalline mass on cooling. After this, permanent oil passed over, which grew denser and darker as the distillation proceeded. The vapours in the retort seemed at the end to have a green colour. When the distillation was stopped there remained in the retort a black-looking liquid mass, which set on cooling, and then resembled pitch in appearance. The experiment was quite a preliminary one, and I have not yet repeated the

7. It is much to be regretted that the recorded information regarding other processes of the oxidation of turpentine and their products is not more complete and precise, for it is mainly by the light of such knowledge that chemists trust to ascertain the constitution of this and the allied hydrocarbons. I trust I may be excused for saying chemists as a body are too fond of confining their studies to a limited number of the products of any one process, and they preferably choose of course the most crystalline of these. This is unfortunate, because any one reaction which may be worked out is not rarely regarded as the only one which occurs in a given process, whereas th

truth is more often that it is only one of a large number | I did not follow them up, owing to the fact that about that that really occur.

When turpentine is oxidised by heating it with plumbic oxide, it is said to yield teretinic and formic acids, thus:2C10H16+702=2C9H14O5+2CH2O2.

This reaction, undoubtedly, does not express the whole truth. Then, again, Hempel has stated that when turpentine is oxidised with chromic acid it yields terpenylic acid, CH1204. This is an important observation, but would be much more valuable if all the accompanying products were also studied and defined.

By oxidising turpentine with nitric acid, toluic acid, C8H8O2, and terephthalic acid, C8H604, are also said to result, but Wright has raised the question whether the terephthalic acid thus obtained is not due merely to the presence of cymene in the turpentine operated upon.

More recently, however, Hempel has repeated the statement that these acids are obtained by the process above indicated. They are also said to be accompanied with terebic acid, C,H10O4, terebenzic acid, C,H,Ö2, and terechrysic acid, C6H8O5.

This variety of products attending the use of such powerful oxidants as nitric acid or an acid solution of potassic dichromate seems clearly to establish the great

time manures ceased to be analysed in our laboratory. I showed that the partial decomposition of nitrates by sodalime was well known, and was stated in, e.g., Fresenius's " Quantitative Analysis" and Church's "Laboratory Guide." I described encouraging results obtained by making a combustion of nitre with iron filings and sugar. I was more successful when I adopted the following plan:-The nitre was dissolved in caustic alkaline solution, iron filings added, and distillation of the mixture to a pasty state carried on in a retort. The results, in fact, erred on the side of excess. I proposed that, in a mixture containing nitrogen in the form of ammonia salt, nitrate, and organic matter, the distillation should be carried on to the above point, and that then the pasty residue should be cooled. In this state it solidifies, and may be powdered, mixed with soda-lime, and a combustion of the mixture made to determine the residue of the organic nitrogen. I should be glad if Mr. Tatlock would carry out this idea.

RELATIONS BETWEEN THE ATOMIC WEIGHTS AND CERTAIN PHYSICAL PROPERTIES

OF ELEMENTS AND COMPOUNDS.*

advantage of employing the mildest possible oxidising (MELTING- AND BOILING-POINTS AND HEATS OF FORMATION) agent where it is desired to obtain a knowledge of the constitution of substances. Indeed, the presumption is that, since it is possible to resolve turpentine into carbonic anhydride and water, if the oxidation with nitric acid be continued for a sufficient period, not only the products previously indicated but a further vast number may be intermediately produced.

ON SOME ANALYSES OF IRON. By SERGIUS KERN, M.E., St. Petersburg.

In several articles inserted in this journal the author has pointed out that in many cases the chemical analysis of iron or steel cannot give an idea of the quality of the metal. The following is a short account of some experiments executed some time ago.

Some pieces of rolled iron (boiler plates) prepared from a very pure pig-iron were sent for analysis. The iron, however, proved to be of a bad quality, and could not stand all the necessary tests. The following are the results of the analysis :

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By THOMAS CARNELLEY, D.Sc., Assistant Lecturer on Chemistry in Owens College, Manchester.

THE object of the present paper is to trace the influence of the atomic weights on the melting and boiling-points and heats of formation of elements, and especially of their compounds. It is shown that, as regards the elements, the melting-points are a periodic function of their atomic weights, whilst, for compounds, the following conclusions are drawn :

I. That the melting and boiling points and heats of formation of the normal halogen compounds of the elements are a periodic function of the atomic weights of the constituent elements.

II. That the influence of the halogen on these same

physical properties increases with the number of its atoms in the compound.

III. That in any normal halogen compound the influence of either of the elements on the melting- or boiling. point increases with its own atomic weight, and decreases with the atomic weight of the other element.

IV. The melting- or boiling-point or heat of formation of a bromide is always nearer to that of the corresponding chloride than to that of the corresponding iodide; and that the melting- or boiling-points of the halogen compounds of the middle member of three consecutive elements of the same group are always nearer to those of the first member (i.e., the one with least atomic weight) than to those of the last member.

The former of these phenomena probably depends on the fact that the atomic weight of Br is nearer to that of Cl than to that of I, i.e., less than the mean of the two: and the latter on the fact that the atomic weight of the middle member of three consecutive elements of the same group is always less than the mean of those of the other two elements.

V. That the melting- and boiling-points of the halogen compounds of the elements belonging to the first and second groups of Mendelejeft's classification are widely separated from those of the other groups, being in fact considerably higher. Different relations too often appear to exist between the melting-points of the even members of these two groups to those which exist between groups (3 to 7) inclusive; while the compounds of the elements, which are often placed in the odd divisions of the first and second groups, are generally altogether irregular. In Abstract of a Paper read before the Royal Society, June 19, 18

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