Obrazy na stronie



Chemical Notices from Foreign Sources. { , if they came back, as I thought they might possibly be CHEMICAL NOTICES FROM FOREIGN due to other causes. However, she would not. I analysed the paper and found o-35 grm. As2O3 per

SOURCES. square foot, but that will scarcely represent the total amount because the paper was wetted in order to remove it, and the greater proportion of the bright green flowers Note: All degrees of temperature are Centigrade, unless otherwise

expressed washed off. There was very little copper present. I may mention that the lady's husband was not affected in the Comptes Rendus Hebdomadaires des Séances, l'Académie de slightest degree.--I am, &c.,

des Sciences. No. II, March 17, 1879.

A. PERCY SMITH. Temple Observatory, Rugby

New Experiments Telephones without April 3, 1879.

Diaphragm.-M. Ader.— The author's experiments demonstrate the truth of the opinion of M. du Moncel

concerning the origin of the sounds reproduced in the PURE CAUSTIC POTASSA.

telephone. To the Editor of the Chemical News.

New Combinations of Hydrochloric Acid with

Ammonia.-L. Troost.—The author remarks that hydroSir,-With reference to the methods for the manufa&ure chloric acid and ammonia have hitherto been obtained of potassium indide as described by E. Schering (Chemi. only in the proportions which form sal-ammoniac, CAL News, vol. xxxix., p. 118), he very justly ascribes the analogous to common salt. No hydrochlorate of this chief objeâion to the process in which iodine is intro chloride has yet been discovered, nor an ammonic hydroduced into caustic potassa and fused with carbon, to be chlorate with excess of base. He has discovered a great the difficulty of obtaining caustic potassa of sufficient number of curious compounds formed by dry ammonia purity, the presence of sulphate and soda salts being with hydrochloric acid, hydrosulphuric acid, and other most objecionable. A caustic potash pra&ically free acids, both mineral and organic. He takes ammoniacal from these and other impurities has hitherto been un. gas absolutely dry and free from every trace of compound obtainable at a commercial price, and the introduction of ammonias, saturates it with pure dry hydrochloric acid, such an article suitable for the manufacture of potassium and submits the sal-ammoniac thus obtained and distilled iodide and other industries has long been a desideratum in a close vessel to the action of a large excess of gaseous in the chemical world. This difficulty has but lately been ammonia, refrigerating to different degrees. He thus removed by the manufa&ure on the large scale of caustic obtains two well-defined compounds, chara&erised by potash at St. Helens, by the Greenbank Alkali Works their point of fusion, their crystalline stru&ure, and their Company, of a purity which leaves nothing to be desired, tension of dissociation. The former of these, tetra-ama sample which recently came under my notice possessing monic hydrochlorate, HC1,4NH3, melts at +7°, and its total impurities under one per cent, of which only oʻz crystals depolarise light powerfully. The other com. was in the form of sodium hydrate. The removal of the pound, hepta-ammonic hydrochlorate, HCI,7NH3, melts difficulty of obtaining a caustic potash of the necessary at - 18o. purity being removed, the process as described above for

Combinations of Hydrogen Phosphide with ihe manufacture of potassium iodide appears to me to be Cuprous Chloride and its Determination in Gascous the simplest and best, and having at one time been en- Mixtures.-J. Riban.—The compound Cu2Cl2,2 PH3, gaged in the manufacture of the article, I can therefore chloride of cuproso-diphosphonium, is obtained by slowly speak with some experience.-I am, &c.,

passing hydrogen phosphide into a solution of cuprous A. R. Garrick, Ph.D., F.I.C. chloride, refrigerated by means of ice. Hydrogen phos. St. Helens, April 3, 1879.

phide present in gaseous mixtures may be determined by agitation along with a solution of cuprous chloride in hydrochloric acid.

The Crystalline Forms of the Compounds of the OBITUARY.

Stanmethyls and of their Homologues.-M. Hiortolahl.-Not susceptible of useful abstradion.

New Method of Treating Iron and Copper Pyrites J. M. MERRICK.

in the Dry Way.-L. Simonin.-An account of J.

Hollway's experiments. We regret to announce the death of Mr. J. M. Merrick, of

The State in which the Precious Metals are found Boston, U.S., who was an occasional contributor

in some of their Combinations, in Ores, Rocks, and our columns. Mr. Merrick died on the 25th day of Artificial Products.-E. Cumenge and Edmond Fuchs. February last, at the early age of forty-one years. In his professional life he had gained the respect of all who not native but in combination with antimony, and is in.

-The authors find that in certain pyrites gold is found knew him by his uprightness of character and the ready capable of being taken up by mercury. courtesy with which he imparted his knowledge to other members of the chemical profession.

Constitution of Coal.-E. Guignet.—The author on treating dry powdered coal with phenol has extracted as

much as 4 per cent of a brown matter. If coal in very An Electric Blowpipe.—M. Jamin.-The author oxalic acid and trinitro-resorcin are distinctly recog:

fine powder is treated in a cohobator with nitric acid, remarks that the ele&ric arc which plays between two nisable among the products. Resorcin was not detected carbon condu&ors is a true current. If submitted to the in the coa influence of a neighbouring current, of a solenoid, or of a magnet, it experiences an action regulated by the laws of

Alcoholic Fermentation.-P. Schützenberger and A. Ampère, identical with that experienced by any metallic Destrem.- !f yeast is placed in such conditions as to conductor put in its place, but as its mass is exceedingly prevent

its development and multiplication it nevertheless trilling its speed is considerable. The author takes preserves its power of decomposing sugar, and if it acts advantage of this fa&. to submit small quantities of upon sugar it de-assimilates more nitrogen than if prematter io an intense heat. By causing the arc to be served in presence of water without sugar and oxygen. driven upon lime, magnesia, or zirconia the light is Determination of Glucose in Blood.-P. Cazeneuve. directed downwards, and its intensity is increased at --The author criticises the method of determination fol. least three-fold.-Comptes Rindus.

lowed by C. Bernard as the progress of the reduction of


,} April 10, 1879. Chemical Notices from Foreign Sources.

163 the cupro-potassic liquid is often uncertain when the re- , a&tion of sulphuretted hydrogen upon glyoxylic acid in adion approaches its limit. It is also reduced by other presence of silver oxide. principles present in the blood. The author thinks that

Mineral Waters near Buda Pest.-M. Ballo.—This glycæmia should be studied anew when a more accurate memoir may possibly be of medical interest. analytical procedure has been devised. Derivatives of Normal Methyl.oxyl-butyric Acid. - The object of this communication is to throw light

Studies in the Naphthalin Series.-Raphael Meldola. -E. Duvillier.--An account of the methyl-oxyl-butyrates upon the constitution of the naphthalin derivatives. The of ethyl and methyl and of methyl-oxy-butyramid.

author gives an account of dibrom-acet-naphthalide. Nature of the Albumen of Hydrocele.-M. Bechamp. - Three distiną albumens are present different from-In describing the sulpho-cresolic acids, the author re.

Sulph-etheric Acids of the Phenols.-E. Baumann blood albumen.

marks that the sulpho-para-cresolate of potassium is a Modifications of the Physical Properties of Starch. constant ingredient in the urine of horses and probably -F. Musculus.-Amylaceous matter may exist either in also of other mammals. the colloid or the crystalloid state. When crystalline it Bromo-acetic Ethyl-ether.-F. Kessel.-A lengthy is soluble even in cold water.

memoir, not adapted for abstraction.

Adion of Dry Ammonium Sulphate upon Dry Berichte der Deutschen Chemischen Gesellschaft zu Berlin, Koehler. The author obtains ethyl-amin, but in small

Barium-ethyl Sulphate in Presence of Baryta.-H. No. 15, 1879.

quantity only. The Chloranilins.-F. Beilstein and A. Kurbatow.An account of the di-, tri-, and tetra-chloranilins. The Hydrochloric Acid.-H. Kohler.-The products formed

Decomposition of Ethyl-sulphates by Gaseous authors propose to found the nomenclature of these com

are free sulphuric acid, barium sulphate, and chlor-ethyl. pounds on the relative position of the chlorine atoms. Para-di-propyl-benzol and Certain of its Deriva.

Tropæolin as an Alkalimetric Indicator.—Dr. Lunge.

-The author confirms the statements of Miller concern. tives.-H. Körner.--An account of sulpho-para-di-propyl. benzolic acid

with its lead, barium, and calcium salts of ing the use of tropæolin 00 for the titration of sodium dinitro-para-di-propyl-benzol, and of propyl-benzoic acid. Not merely the carbonate but sodium sulphide (in the

carbonate, and for determining the free acid in alumina. Determination of Vapour.Densities.-V. Meyer.- crystalline state) may be accurately titrated in the cold Not intelligible without the accompanying engraving.

with sulphuric acid, using tropæolin as indicator. On Occurrence of Furfurol in Commercial Glacial the slightest excess of acid appearing, the yellowish Acetic Acid.-V. Meyer.— The author has found that colour changes at once to a magenta and then to orange, glacial acetic acid, represented as containing from 99 to which after a few seconds disappears entirely. Tro100 per cent of real acid and apparently of unexceptional pæolin 000 undergoes the reversed play of colour, being quality, assumed a splendid red colour on contact with yellow in acid solution, but turning to a magenta-red in aniline, but lost this property on distillation with chromic alkalies. acid. This colouration was due to the presence of furfurol of which o'108 grm. was found per litre of acid.

Reimann's Färber Zeitung, Variability of the Colouring-matter of Red Wine.

No. 11, 1879. - J. Erdmann.-The author traces decided differences in the behaviour of genuine wine of one and the same

Two new green dyes have been introduced into practical

use ; 'the Vert acide of A. Poirrier, of Paris, and the growth according to its age.

Victoria green of the Baden Aniline Company. The Spectroscopic Researches on the Constitution of price of the latter is only 165. per kilo. Solutions.-H. Burger.-In this paper the author com

The red azo-colouring-matters are fast superseding municates merely his methods of observation.

cochineal in the flannel dye works of Saxon They have Malabar Gum Kino and a New Compound, Kinoin. the advantage of not being injured by washing. -C. Etti.—The author added kino to twice its weight of boiling dilute hydrochloric acid (1 : 5). Kino-red sepa

No. 12, 1879. rates out as a soft mass, which slowly hardens on cooling,

Washing Wool with Ether and Alcohol.—The while the kinoin remains in solution, contaminated with result of the experiments made at Ensival, near Verviers, a little kino-red. When purified it crystallises in colour is stated as follows :—70,000 kilos. wool and 16,000 kilos. less well-formed prisms, sparingly soluble in cold water, yarn were extracted. The former yielded 15,800 kilos, readily at a boil, and very easily in alcohol of every con

of oil, or 22:6 per cent, and the latter 2400 kilos., or centration. The solution is not precipitated by glue and

15 per cent.

The oil was sold at 39 to 40 francs per is coloured red by ferric chloride. The composition of

100 kilos. The loss of ether amounted to 4'9 kilos. per kinoin is C14H1206.

100 kilos. o wool treated. Mono- and Diphenyl-arsenic Compounds.- W. La Coste and A. Michælis.-The readiness with which phos.

No. 23, 1879. phenyl chloride can be obtained from phosphorus chloride It appears that milk is dyed in the cows. If fed with and benzol induced the authors to examine if this reaction Anchusa tinctoria they yield a blueish milk, if with Rheum could not be generalised so as to serve for the preparation palmatum a yellowish, and if with madder or bed-straw of the corresponding arsenical compounds.

(Galium) a reddish. Tri-phenyl-arsin and its Derivatives.-W. La Coste and A. Michælis.

Justus Liebig's Annalen der Chemie, Mono-tolyl-arsenic Compounds.-W. La Coste and

Band 196, Hest 1. A. Michælis.—These two papers may be regarded as

Constitution of Phenanthren.-Gustav Schultz,continuations of the foregoing.

The author infers that phenanthren-quinon and conse. Schizomycetic Fermentations.-An examination of quently phenanthren are to be regarded as diortho-comthe fermentations of erythrite, glycerin, mannite, citrate pounds. of lime, malate of lime, &c., infected with cow-dung, in.

On Phenanthren.quinon.-R. Anschütz and Gustav fusion of hay, and certain varieties of purulent matter. Schultz.-An account of the preparation of this compound

Thioglycolic and Thiodiglycolic Ethers.-C. Böt- and its behaviour with aqueous alkalies and lime, with tinger.-The author has obtained these produas by the alcoholic potassa, and alcoholic ammonia.


acid and from a chlor-propionic acid is evidence for the EXPERIMENTAL

CHEMICAL NEWS, 164 Meetings for the Week.

April 10, 1879. Researches on Hydrogen peroxide.-E. Schæne.

The The author has investigated the behaviour of hydric per- MONTHLY JOURNAL OF SCIENCE oxide with the oxygen compounds of thallium. He finds that thallium paper is turned brown by the vapour of BIOLOGY, ASTRONOMY, GEOLOGY, INDUSTRIAL ARTS hydric peroxide in consequence of the formation of thallic

MANUFACTURES AND TECHNOLOGY, oxide. Hence the browning of thallium test-papers on exposure to atmospheric air is by no means a proof of the

Edited by WILLIAM CROOKES F.R.S., &c. presence of ozone. On Aurin.-R. S. Dale and C. Schorlemmer.-The

The third number of the Monthly Series (April, 1879) is authors describe their conversion of "red corallin” or

Now Ready, “peonin" into rosanilin. They have further examined

Price One Shilling and Sixpence. ammonia-aurin, tetrabrom-aurin—which latter compound is very similar to tetrabrom-rosolic acid, soluble in alkalies

CONTENTS. with a fine violet colour, whilst its acidified solutions dye I. Is Nature Perfect ? silk and wool a dark violet. They have further investi- II. Thoughts on Our Conceptions of Physical Law. By Pro

Francis E. Nipher. gated the action of acetyl chloride and anhydrous acetic

III. The Old Stannaries of the West of England. By James acid upon aurin, the compounds of aurin with acids. The

Quick. compounds of aurin with acids are red like the aurin IV. A New Theory of Terrestrial Magnetism. By Profs. Perry

and Ayrton. itself, whilst those with the acid sulphites of the alkali

V. The Jablochkoff Candle: Its Practical Results in London. metals and with anhydrous acetic acid are colourless like

By Charles W. Quin. leukaurin. The homologue of aurin rosolic acid likewise VI. The Tornado at Wisconsin in 1878. forms with acids well crystallised compounds, and as a

VII. The Electric Light for India.

VIII. Painless Death. powerful base. Hence it should not be considered as an Correspondence-The Sea-Serpent-Spider's Web for Micrometers acid, and might be more appropriately named rosaurin,

-Adhémar's Theory of Evolution-The Senses

of the Lower Animals-Optical Illusions. On Pyruvic Acid.—Dr. C. Böttinger.—The author

Reviews of Scientific Works-Science Notes-Proceedings of shows that the quantity of pyruvic acid obtained from

Scientific Societies. glyceric acid is so trifling that it is inadmissible to make use of this manner of formation for the dedu&ion of a

London : 3, Horse-Stoc Court, Ludgate Hill. constitutional formula for the latter acid. The demon. strated identity of the sulpho-lactic acid from pyruvic

In one volume 8vo., pp. 1048, £1 11s. 6d.,


PURE, APPLIED, AND PHYSICAL CHEMISTRY. By Communications from the Chemical Laboratory mistry in the Royal School of Mines, &c.

E. FRANKLAND, Ph.D. (Marburg), D.C.L., F.R.S., Protessor of Cheof the University of Kasan.—These consist of papers

ALSO BY PROFESSOR FRANKLAND, on Allyl-dipropyl-carbinol, by P. and A. Saytzeff; and on

FOR CHEMICAL Allyl-di-ethyl.carbinol, by A. Schirokoff and A. Saytzeff. | LECTURE NOTES

STUDENTS. Post 8vo., Fifth Thousand of Vol. I. (Inorganic) Action of Tertiary Butyl-iodide on Isobutylen in


Second Edition of Vol. 11. (Organic), 5s. Presence of Metallic Oxides.-J. Lermontoff.—Not

JOHN VAN VOORST, 1, Paternoster Row. susceptible of useful abstraction. Tetra-methyl-ethylen and its Derivatives, and the

hemist (age 21), who has studied for five Chemical Structure of Pinakon.-D. Pawlow.-Not

years in Scotch and German Laboratories, and who has had

considerable experience in analysis and research, desires Engagement suitable for abstraction.

as Assistant Chemist in a College or Works. Good references.

Apply, J. T., 26, Royal Exchange Square, Glasgow.
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have the advantage of improving himself and gaining experience in presence of borax all the colouring-matters of plants commercial analyses. --Address, Beta, CHEMICAL News Office, Boy except chlorophyll are diffused, so that the plant becomes Court, Ludgate Hill, London, E.c. colourless ; red Aowers, for instance, become green. The Runcorn Soap and Alkali Co., Limited, Mr. Edison said to have invented an ink which gives Apprentice for three or four years. Apply by letter only to the

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History of Detonating Agents. . April 18, 1879.


made the subject of study by the le&urer during the last THE CHEMICAL NEWS.

NEWS. of

ten years, and some of the earlier results published by him

experimental inquiries of analogous character by Champion VOL. XXXIX. No, 1012.

and Pellet and others.

Some of the chief results attained by Mr. Abel's experi. ments may be briefly summarised.

It was found that the susceptibility to detonation, as RECENT CONTRIBUTIONS TO THE HISTORY initiative detonation, is not confined to gun-cotton, nitro

distinguished from explosion, through the agency of an OF DETONATING AGENTS.

glycerin, and preparations containing those substances,

but that it is shared, though in very different degrees, by By Professor ABEL, C.B., F.R.S.

all explosive compounds and mixtures.

It was demonstrated that the detonation of nitro. AMONG the many explosive preparations which have during glycerin and other bodies, through the agency of an initithe last thirty years been proposed as substitutes for gun. ative detonation, is not ascribable simply to the direct powder, on account of greater violence and other special operation of the heat developed by the chemical changes merits claimed for them, not one has yet competed with it of the charge of detonating material, and that the remark. successfully as a propelling agent, nor even as a safe and able property possessed by the sudden explosion of small sufficiently reliable explosive agent for use in shells ; for quantities of certain bodies (the mercuric and silver ful. industrial applications and for very important military or minates) to accomplish the detonation of nitro-glycerin naval uses, dependent upon the destructive effects of ex- and gun-cotton, is accounted for satisfactorily by the me. plosives, it has had, however, to give place, to a very im. chanical force thus suddenly brought to bear upon some portant extent, and in some instances altogether, to pre- part of the mass operated upon. Most generally, there. parations r 'gun-cotton and nitro-glycerin.

fore, the degree of facility with which the detonation of a But ... :e appeared little prospect that either gun substance will develop similar change in a neighbouring cotton ut nitro-glycerin, whether used in their most simple explosive substance, may be regarded as proportionate to conditions or in the forms of various preparations, would the amount of force developed within the shortest period assume positions of practical importance as explosive of time by that detonation, the latter being in fact analoagents of reliable, and therefore uniformly efficient, cha. gous in its operation to that of a blow from a hammer or rader, until the system of developing their explosive force of the impad of a projectile. through the agency of a detonation, instead of through the Thus, explosive substances which are inferior to mercuric simple agency of heat, was elaborated.

fulminate in the suddenness, and the consequent moBefore the first step in this important advance in the mentary violence, of their detonation, cannot be relied application of explosive agents was made by Alfred Nobel, upon to effect the detonation of gun.cotton, even when about twelve years ago, the very variable behaviour of such used in comparatively considerable quantities. Percussion substances as gun-cotton and nitro-glycerin, when exposed cap composition, for example, which is a mixture of fulto the heat necessary for their ignition under compara- minate

with potassium

chlorate, and is therefore much less tively slight modifications of attendant conditions (e.g., as rapid in its adion than the pure fulminate, must be used regards the completeness and strength of confinement or in comparatively large quantities to accomplish the detothe position of the source of heat with reference to the nation of gun-cotton. main mass of the material to be exploded) rendered them The essential difference between an explosion and what uncertain in their a&ion, and at any rate, only applicable we now distinguish as a detonation lies in the comparative under circumstances which confined their usefulness i suddenness of the transformation of the solid or liquid within narrow limits. The employment by Nobel of an explosive substance into gas and vapour. initiative detonation, produced by the ignition of small

The gradual nature of the explosion of gunpowder is quantities of mercuric fulminate or other powerful deto- illustrated, in its extreme, by burning a train of powder in nating substances, strongly confined, for developing the the open air; the rapidity and consequent violence of the violent explosion, or detonation, of nitro-glycerin, opened explosion is increased in proportion to the degree of cona new field for the study of explosive substances, and the finement of the exploding. charge, or to the resistance first practical fruit was the successful application of plastic to the escape or expansion of the gases generated upon preparations of nitro-glycerin and of compact forms of the first ignition of the confined substance. In proportion compressed gun-cotton, with simplicity and certainty, to as the pressure is increased under which the progressive the production of destructive effects much more consider transformation of the explosive takes place, the rapidity able than could be accomplished through the agency of with which its particles are successively subjected to the much larger amounts of gunpowder, applied under the most

action of heat is increased. favourable conditions. Whereas very strong confinement

In the case of a very much more sensitive and rapidly has been essential for the complete explosion of these sub- explosive substance than gunpowder, such as mercuric stances, so long as the only known means of bringing fulminate, the increase in the rapidity of its transformaabout their explosion consisted simply of the application tion, by strong confinement, is so great that the explosion of fire or sufficient heat, no confinement whatever is needed assumes the character of a detonation in regard to sudder.. for the development, with certainty, of a decidedly more ness and consequent destructive effect. A still more ser.. violent explosive action t n they are capable of exerting sitive and rapidly explosive material (such as the silver when thus applied, if the are detonated by submitting fulminate and iodide of nitrogen) produces when exploded some small portion of the nass to the blow or concussion in open air effects akin to those of detonation ; yet even developed by a sharp detonation, such as is produced by with these bodies confinement operates in increasing the the ignition of a small quantity of strongly confined mer rapidity of the explosive to suddenness, and consequently curic fulminate.

in developing a more purely detonative action. Thus, the The cunditions essential to the development of detona. violence of explosion of silver fulminate is decidedly ir.. tion in masses of nitro-glycerin and gun-cotton, or pre- creased by confining the substance in a stout metal case, parations of them, and the relations to and behaviour to. and the enclosure of iodide of nitrogen in a shell of plaster wards each other of these and other explosive bodies, in of Paris has a similar effect. With chloride of nitrogen, their character or functions as detonating agents, has been the suddenness of detonation, and consequently the violence

of action, was found to be very greatly increased even by * Abstract of 2 Paper read before the Royal Institution of Great confining the liquid beneath a thin layer of water. Britain, Friday, March 21, 1879.

Detonation, developed in some portion of a mass, is




End-on Illumination in Private Spectroscopy.


April 18, 1879. transmitted with a velocity approaching instantaneousness END-ON ILLUMINATION IN PRIVATE throughout any quantity, and even if the material is ļaid

SPECTROSCOPY, out in the open air in long trains composed of small masses. The velocity with which detonation travels along trains thirty or forty feet in length, composed of distinct APPLICATIONS TO BOTH BLOWPIPE FLAMES masses of gun-cotton and of dynamite, has been deter

AND ELECTRIC ILLUMINED mined by means of Noble's chronoscope, and was found

GAS-VACUUM TUBES. to range from 17,000 to 24,000 feet per second. Even when trains of these explosive agents were laid out with Astronomer Royal for Scotland, and Past President of R.S.S. Arts.

By PIAZZI SMYTH, intervening spaces of half an inch between the individual

(Continued from p. 146). masses composing the trains, detonation was still transmitted along the separated masses with great though diminished velocity.

PART II. The suddenness with which detonation takes place has

Flame-Spectroscopy. been applied as a very simple means of breaking up shells into The various kinds of fame most frequently employed to small fragments, and scattering these with considerable vio render substances incandescent in spearoscopy, are lence, with employment of very small charges of explosive agent. Thus, by filling a 16-pr. common shell completely

(1). The alcohol lamp: with water, and inserting a charge of 1 oz. of gun-cotton (2.) The Bunsen gas burner. fitted to a detonating fuze, the shell being thoroughly closed 13.) Thé coal-gas blowpipe driven by air. by means of a screw-plug, the force developed by the deto. (4.) The coal-gas blowpipe driven by oxygen. And nation of the small charge of gun-cotton is transmitted in- 15.) The oxy-hydrogen blowpipe. stantaneously in all directions by the water, and the shell

Of these five kinds, I choose the middle one as a stand is thus broken up into a number of fragments averaging by; for while its pointed conical flame is more definite, fourteen times the number produced by bursting a shell precise, and workmanlike than the wavy loose Alames of of the same size by means of the full amount of powder the first two, it is cheaper, more usually met with, and which it will contain (13 ozs.). Employing 1 oz. of pow

more frequenlty ready for ading, than the two latter ; der in place of } oz. of gun-cotton in the shell filled with while it links us on to a very fair amount of heat for any water, the comparatively, very gradual explosion of the Aame-work, or to what we may consider a standard step powder charge is rendered evident by the result, the shell in temperature throughout all these researches. The being broken up into less than twenty fragments by the above coal-gas and air blowpipe has, moreover, the shock produced by the first ignition of the charge, trans

further recommendation that, dúll as its blue-gray Rame mitted by the water. In this case the shell is broken up may appear to the eye, yet it contains several colours by the minimum amount of force necessary for the purpose, which separate into distina, discontinuous bands under before the explosive force of the powder charge is properly the spectroscope ; and they would probably be more often developed. Extensive comparative experiments, carried utilised for spectroscopic science if they could only be on not long since by the Royal Artillery, at Okehampton, made decidedly brighter. But brighter it must be without demonstrated that this simple expedient of filling common

any change of temparature, and also without our losing shells with water and attaching a small charge of gun. the use of the simple open flame to vapourise at pleasure cotton with its detonator to the fuze usually employed, adventitious and external matters in the usual flame spec. allowed of the application as efficient substitutes for the troscopic manner. comparatively complicated and costly shrapnel and seg. Prof. Swan of St. Andrews, who first gave a large, ment shells.

scientific and indeed very noble account of this blowpipe Another illustration of the sharpness of adion developed Aame and its spectrum, and gave it so far back as 1856, by detonation as compared with explosion, consequent

was so impressed with the importance of brightening, if upon the almost instantaneous character of the meta- possible, its faint bluish light, that he plac three small morphosis which the explosive agent undergoes in the blowpipes (of his own ingenious making) one behind the cases of detonation, is afforded by a method which the other, and looked through all three fames at once. lecturer applied some years since for comparing the violence Thereby he was enabled to measure all the the leading of action of charges of gun-cotton and of dynamite arranged details of four out of the really five coloured bands in this in different ways. The charges (5 lbs.) to be detonated spectrum ; but failed to see the lines in the first of these were freely suspended over the centres of plates of very

as to position, viz., the orange-amber band. After him soft steel of the best quality, which rested upon the flat several observers in London, Paris, and Manchester face of a massive block or anvil of iron, having a large recurred to single or double blowpipes, but unfortunately central circular cavity. The distance between the upper in conjunction with pure oxygen gas; for by that emphatic surface of the plate and the charge suspended over it was

addition, the temparature of their names was so greatly 4 feet. The sharp blow delivered upon the plate by the raised, that they are all necessarily excluded from the air suddenly projeAed against it by the force of the present inquiry. detonation when the charge was fired forced the metal

More recently I have obtained a copy fron Paris of the down into the cavity of the anvil, producing cup-shaped late Padre Secchi's grand work entitled " Le Soleil ” (2nd indentations, the dimensions of which afforded means of ed. 1875); and on p: 246 of vol. i.,—where that brilliant comparing the violence of the detonation. A much larger scientist has introduced, though without acknowledg. charge of powder exploded in a&ual contact with the plate ment, a copy of my own Edinburgh Observatory sketch in would produce no alteration of form in the metal, and the 1872' of the whole five bands of the simple blowpipe same negative result would be furnished by the explosion spe&rum,-he yet, in alluding to it in the text, speaks of over the plate of a heap of loose gun-cotton of the same

the bands as being, in all ordinary cases witnessed by or greater weight than the charges detonated. The above him, three only, and their colours" green and blue": method of experiment was devised, in the first instance, really citron, green, and blue; in which case he could by Mr. Abel, in July, 1875, for comparing the quality of only have seen the three brighter ones of the five. some specimens of Llandore steel proposed to be used by In Prof. Roscoe's well-known volume of “Lectures on the Admiralty for ship-building purposes with samples of SpeArum Analysis” (1st ed. 1868), there is a coloured malleable iron, and it has since been employed by Mr. representation of the coal-gas speátrum with five bands, Adamson in carrying out a very useful series of experi, and some of them with lines ; not perhaps intended to be ments, recently communicated to the Iron and Steel very acturate, but most assuredly 'not indicating the Institute. (To be continued.)

* Read before the Royal Scottish Society of Arts, February 10, 1879.

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