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luminous rays away from the pith disk. I think I sucTHE CHEMICAL NEWS. ceeded in this ; but it was not easy, owing to the fluores
cence of the card and other surfaces on which stray rays
fell. The spot of light moved 2 divisions, which were Vol. XXXIV. No. 890.
increased to 5 when the invisible rays were further concentrated by a quartz lens. The interposition of the iodine cell cut off the whole of the action. The alum
plate cut off about half of the action, but scarcely more ON REPULSION RESULTING FROM ihan would have been cut off had a piece of colourless RADIATION.-PART II.*
glass of the same thickness been interposed, and it must
be remembered that the alum plate has glass and Canada By WILLIAM CROOKES, F.R.S., &c.
balsam on each side. (Continued from p. 242).
III. A similar experiment with the solar spectrum gave
the following deflections, glass prisms being used :110. An examination of this Table shows that the action
Ultra-red is by no means confined to the rays usually called heat,
6 i.e., to the extreme- and ultra-red of the spectrum. The
5 strong action obtained when the light is filtered through
45 greenish glass and alum, or through ammonio-sulphate of
3'5 copper, shows that luminous rays produce a similar move
Ultra-violet ment of repulsion.
Unfavourable weather has prevented me from obtaining Although I give the number of divisions shown by the good quantitative results with the different rays of the luminous index, I attach little importance to them as solar spectrum ; but I have tried numerous qualitative ex. quantitative measurements. They are only single obserperiments which leave no doubt on my mind that any ray, vations, and were taken before I had succeeded in getting from the invisible ultra-red to the invisible ultra-violet, anything like the same sensitiveness I can now attain in will produce repulsion in a vacuum. The following is an the apparatus. As illustrations of the fact, however, that experiment tried with the electric light. The spectrum the more refrangible rays of the spectrum act as well as was formed with a complete quartz train, no glass what the lower rays, they may be taken as trustworthy.* ever being in the path of the rays. The purity of the 112. In my former paper on this subject I have already spectrum was evidenced by the fact of the lines being mentioned in detail that at a certain point of rarefaction sharp when thallium, sodium, or lithium was put between there is neither attraction nor repulsion when radiation the carbon poles. The spectrum was so arranged that falls on the movable index (30, 43, 47, 66). I have long any desired ray could be thrown on to a lampblacked pith tried to ascertain the law governing the position of this surface, screens being interposed to cut off the action neutral point. My results are not yet ready for publicawhen desired. The torsion balance was similar to the tion; but they are shaping themselves in order, and will, one used in the last-named series of experiments (104), I trust, lead to a true explanation of the cause of these but was not quite so sensitive.
phenomena. The extreme red rays were first brought into position. The barometric position of the neutral point dividing On removing the screen the luminous index moved 9 divi- attraction from repulsion varies according to circumsions on the scale. The screen being replaced, the index stances; among these may be mentioned the density of returned to zero. A solution of iodine in disulphide of the substance on which radiation falls, the ratio of its carbon was now interposed, and the screen again removed. mass to its surface, its radiating, and conducting-power The repulsion was almost as strong as before, showing for heat, the physical condition of its surface, the kind of that this liquid was transparent to the ultra-red rays. gas filling the apparatus, the intensity of radiation, and
The iodine solution was then replaced by a clear plate the temperature of the surrounding atmosphere. of alum 5 millims. thick, and the screen removed; a very Wnen the surface exposed to radiation is pith, the slight movement only took place. The iodine solution neutral point is somewhat low. I have had it vary bewas then put in front of the alum plate, so as to subject tween 50 millims. and 7 millims. (30) below a vacuum. the extreme red rays to a double process of sifting. No It is, however, impossible to ascertain exactly; for a point trace of action could be detected.
of rarefaction can be obtained at which the warm fingers Whilst this double screen was in front of the pith disk, repel, and incandescent platinum attracts. With a heavy the spectrum was gradually passed along, so as to bring metal in the form of a sphere, so as to expose the smallest the rays, one after the other, into position. No effect, surface in proportion to the mass, I have not attained the however, was produced, showing that alum and iodine neutral point until the exhaustion was within a very solution practically obliterate the whole of the spectrum. small fraction of a millimetre (43, 47); whilst if the metal
The alum plate and iodine cell were now removed, and is in the form of thin foil the neutral point may easily be the green of the spectrum (the thallium line) was brought got lower than with pith. into position. The luminous index moved 6 divisions. I am inclined to believe that the true action of radiation The plate of alum cut off only a small amount of this is repulsion at any pressure, and that the attraction oba&ion, but the iodine cell brought the index to zero. served when the rarefaction is below the neutral point is This is a proof that the action in this case was not due to caused by some modifying circumstance connected with the heat-rays of the spectrum, for these are practically the surrounding gas, not necessarily of the nature of airtransmitted by iodine, and cut off by alum.
currents (80). As a proof of this I have not unfrequently The indigo-rays were next brought into position. The obtained repulsion from radiation when the apparatus was spot of light moved 3 divisions on the graduated scale. full of air at the normal pressure. Alum cut off only a very little of the action ; but the 113. The following experiments are too few in number, iodine cell was completely opaque to the rays, and brought and have not been varied sufficiently as to conditions, to the index to zero.
enable many inferences to be drawn from them. HowFinally, the invisible ultra-violet rays of the spectrum ever, they afford glimpses of a law governing the position were brought into position. The train being of quartz of the neutral point. these were abundant. Care was taken to keep any of the A torsion-apparatus was fitted up similar to the one
* A Paper communicated to the Royal Society, March 20, 1875. * Everything is ready to try a series of experiments with the solar From the Philosophical Transactions ofthe Royal Society o London, spectrum, as soon as sunshine is available. The results shall be comvol clxv., pt. 2.
municated in a subsequent paper.
Gauge. Neutral point.
CHEMICAL News, Butter Analysis. 254
Dec. 15, 1876. described in paragraph 102. The beam was of glass, and The crystals selected for the analysis were about # inch at one extremity was fitted with a spring clip, also of long, of a clear dark green colour, and perfectly transglass, so that different bodies could be experimented with. parent. Disks of platinum foil, i centimetre in diameter and It was desired to ascertain the combined action of heat weighing 1:28 grs. each, were prepared, and they were and air on oxychloride of copper. For this purpose a fixed in the clip at the end of the torsion beam, either portion of the substance employed in the above analysis singly or two, three, or four together, in such a manner was placed in the centre of a combustion tube between that while the disk exposed was always i centim. in two plugs of asbestos; air from a gas holder was passed diameter, the weights should be in the proportion slowly through the tube, while the latter was heated 1, 2, 3, 4,
At the other end of the beam a movable gradually up to the highest temperature obtainable with counterpoise was arranged, so that the length of beam à charcoal combustion furnace. This temperature was from the platinum disk to the centre was always the maintained until the sublimate did not appear to increase
further in quantity. When cold the contents of the tube The neutral points were as follows :
were examined. At the cooler part of the tube a sub
limate had formed varying in colour from light yellow to
Diff.= No. of Disks, Barometer.
Differences. dark brown. On examination this proved to be sub
chloride of copper. In the place of the original substance 760 682 78
there remained a brilliant black fritted mass of protoxide 8
of copper. The internal portion of the tube extending for 760 690 70
a short distance from the point where the original sub16
stance was placed, towards that part of the tube where 760 706 54
the sublimate had formed, was converted into a bluish 24
green glass. At the commencement of the experiment, 760 730 30
when the temperature was comparatively very low, oxygen 114. Two pieces of platinum, a and b, were now cut was evolved. I do not know whether this reaction has from the same sheet, each having 1 square centim. of sur.
been noted before, but it is readily observed on heating a face. a was left the full size, but b was earefully folded small portion of atacamite in a test-tube. in four, so as to expose a surface of only at of a square atacamite powder in this case being placed in a platinum
The experiment detailed above was repeated, the centimetre, the weight remaining the same. points were then taken. The average of several observa- boat, all the other conditions remaining the same; the tions (which, however, were not quite so concordant as results were identical with those obtained in the former could have been wished) were, below a vacuum,
experiment. The reaction which takes place when oxyb.
chloride of copper is hea ed with access of air would
therefore appear to be as follows :-
CuCl2+3CuO+4H20=Cu2Cl2+2Cu0+0+4H20. The pieces of foil were then coated with lampblack, and
Laboratory, Wallaroo Smelting Works, observations again taken. This time the neutral points Wallaroo, South Australia,
October 5, 1876. came out
b. 66 millims.
124 millims. An intimate connection is thus shown to exist between
BUTTER ANALYSIS. the absorbing (and radiating) power of the surface on AN IMPROVED METHOD OF ASCERTAINING which radiation falls and the atmospheric tension at which
THE SPECIFIC GRAVITIES OF FATS. the movement is reduced to a minimum. Further experiments on this subject are in progress.
By C. ESTCOURT, F.C.S. (To be continued.)
Analyst to the City of Manchester, Borough of Oldham, &c.
The great advance which has been made in food analysis NOTE ON ATACAMITE.
since the passing of the “Food Adulteration Act of 1872"
is nowhere so apparent as in the methods employed to By T. C. CLOUD, A.R.S.M.
detect adulterations in butter. It is scarcely three years
since the time when the only methods of butter analysis, This mineral is found in large quantities in this district, so-called, consisted entirely of smelling and tasting. and some mines have produced magnificent specimens. Thus we had a butter taste, a tallow taste, and a lard In many cases it is evident that this mineral has been taste. The first advance made was the observations of formed from the oxide most probably by the action of salt the fusing-points of different fats, and the next one was water. I have specimens in my possession consisting of the estimation of the fatty acids present in fats of various a central portion of massive cuprite with crystals of the origin. The last named process has, since its discovery same, the whole being converted to a depth of about by Messrs. Angell and Hehner, been so elaborated by 0:1 inch into atacamite.
various workers, amongst whom are Drs. Dupré and When this mineral occurs in contact with limestone Muter, that nothing further in this direction can be exrock near the surface of the country it is invariably con- pected. verted more or less into green carbonate of copper ; in The process, however, which recommends itself by its some cases this change has only extended to a slight simplicity, and its good results, if properly carried out, is depth, while in others the whole mass is thus converted. that of taking the specific gravities of various fats, butter
The following are the results of an analysis of a well fat amongst others. This process, devised by Mr. James crystallised specimen of atacamite from this district Bell, F.C.S.,principal of the Inland Revenue Laboratory, has (Yorke's Peninsula).
only been slightly modified since its first application. Copper
The modifications were the change of temperature in the Chlorine
water used to compare with the fat, and the use of Protoxide
specific gravity beads. Insoluble residue..
In ascertaining the presence of, and estimating Water, by difference
the quantity of foreign fat in butter by either the fatty acid, or the ordinary specific gravity method, several difficulties present themselves. In the first
Dec. 15, 1876.
255 method the possible loss in manipulation, and the tedious | this method that a dozen observers will (unlike in the nature of the process (shortened as it has been) are strong fatty acid and the gravity bottle method) arrive at the objections. In the second method no objection can be same results. It will be observed that the ordinary way made as to the time occupied, but a serious consideration of calculating the amount of foreign fats is rather in is the extreme care necessary in taking gravities at so favour of the vendor of the adulterated article, as equal high a temperature as 100° F. by means of a specific weights of fats mixed do not produce exactly average gravity bottle. Those who have tried a large number of these gravities, as at first sight might have been supposed. In determinations will see how difficult it is to be certain that conclusion I may point out that each observer should the gravity bottle is filled with the fat and cleared of all out- test his balance and apparatus with the various fats, as side deposits exactly at 100 F. A degree, more or less, is the stationary temperature of his own apparatus may quite equal to 0.5 in the gravity, and this difference will slightly vary from 208 F. certainly occur where two operators are examining the same sample, and sometimes in two experiments by the same operator.
NEW METHOD OF SEPARATING NICKEL Having tried all these methods with fair success I was
AND COBALT. led, by the considerations I have stated, to try whether the specific gravity of fats could be taken by means of a
By ANTHONY GUYARD (HUGO TAMM). specific gravity balance, working by immersion, the tube containing the fats being kept at a constant temperature. The alkaline sulphocyanides exert an unequal action on Naturally my first idea was the water or steam bath, and the sulphides of nickel and of cobalt recently precipitated. I may say at once that no objection can be taken to it on in the cold we do not observe a very marked action, but the ground of high temperature, as the first step in all on raising the temperature we see the sulphide of nickel processes for butter analysis is to heat it on the bath until enter into solution with a very great facility, whilst the the curd and water deposit.
sulphide of cobalt resists more, and only dissolves even I found, however, that the steam constantly deposited in a considerable excess of sulphocyanide, after prolonged on the beam of the balance, and thus affected the results. boiling. This reaction is not sufficiently distind for anaI therefore devised a method free from this inconvenience, lytical application, but by a modification we render it and which I have found to give exceedingly constant practical, and find ourselves in possession of a very eleresults.
gant and very exact method of separating nickel from The balancë I use is one made by G. Westphal, of cobalt. In fact, in cold and very dilute liquids, the sulCelle, Hanover, and works very accurately. The bulb of phide of nickel recently precipitated is dissolved with a this balance is suspended in the test-tube (11 in. by 5) surprising rapidity in cyanide of potassium, whilst sulphide which contains the fat. This test-tube is immersed in a of cobalt is perfectly insoluble. In these conditions the metal tube containing paraffin (any other substance with reaction is so clear and distinct that we may find in the high boiling-point will do), which is closed at the bottom. oxide of nickel traces of cobalt (which we could only This tube is fastened securely by luting, &c., on to the lid detect by the aid of the blowpipe), and effect their sepa. of a small water-bath of suitable size, which has an outlet ration. for steam, to which a glass tube can be attached, and a In the course of an analysis the best way of proceeding tube at the side to indicate the quantity of water in the is as follows :-We separate, in the usual manner, the bath.
cobalt and nickel from the metals which accompany The modus operandi is as follows:- The water-bath is them; then we precipitate both by a slight excess of sulfitted up to the proper height, which should be always the phide of ammonium. We dilute the liquid with a suitable
The metal tube is filled with paraffin, and when quantity of water; then add gradually a weak solution of (heat having been applied) the paraffin is melted a ther-cyanide of potassium, avoiding excess. This operation is mometer is placed on it and the test-tube of fat. When rendered easy by the fact that the mass of sulphides the fat is melted the balance is adjusted, the bulb is im- clears up, and the sulphide of cobalt floats in particles mersed in the fat, and the weights (approximate) are detached from each other, and we distinctly see what placed on the beam. When the temperature of the passes in the liquid. We then filter, collect the sulphide paraffin indicates 206° F. I exactly adjust the weights, and of cobalt, and determine the cobalt in the ordinary way. then when it becomes stationary for a minute, which it To isolate the nickel we acidulate the filtered liquid with does in my bath at 208° F., I put the exact weights on, a slight excess of muriatic or sulphuric acid. The nickel allow it to remain in equilibrium for five minutes, then is precipitated in the state of cyanide, and that so comrecord the weight, which is the specific gravity of the fat pletely that we cannot find traces of it in the liquid. under examination.
This cyanide is collected upon a filter, well washed, then I give below the results of a series of experiments with calcined. Oxide of nickel is thus obtained so pure, in this apparatus.
some cases, that it may be weighed and determined at Temperature of Paraffin
once as nickel. However, in general, it is prudent to No. Description of Fat. Specific Gravities. puri'y this oxide, which often retains silica : in this case
we proceed in the ordinary manner.
The advantage of the process which I propose for the Beef fat
separation of nickel and cobalt is that it permits us to deMutton fat..
termine the nickel without having to manipulate it in the 3. Lard home rendered.. 862:8
state of sulphide--an operation always long, very deli4. Butter M.
cate, and very troublesome. 5. Butter BB...
Under favourable circumstances the analytic process 6. Equal weights of Mutton
that I have just explained will certainly be one of the No. 2 and butter BB.
most simple processes, and may be applied to the separaEqual weights of beef No. I
tion of nickel and cobalt on a large scale.—Bulletin de la 7. and butter M..
Société Chimique de Paris. 8.
Equal weights of lard No.3
865.8 9. Dutch butterine..
Project of a Great Aquarium.–At the Exhibition to
be held at Paris, in 1878, M. Toselli proposes to conIn performing the above experiments I have alternately struct a great aquarium to serve for the display of diving. heated and cooled the fats and found the specific gravities bells, instruments for raising sunken ships and their fairly constant. It is not the least recommendation of cargoes, &c.-Les Mondes.
Bath 203° F.
CHEMICAL News, On Calcium Sulphate.
Dec. 15. 1876. PROCEEDINGS OF SOCIETIES. coloured on exposure to the air. The author has obtained
the diacetyl compound, and also several brominated deri.
vatives of the latter. He hoped soon to lay before the CHEMICAL SOCIETY.
Society a detailed account of the manner of preparation Thursday, December 7th, 1876.
and the properties of these compounds.
Dr. Gladstone having thanked the author in the name
of the Fellows, Dr. J. H. GLADSTONE, F.R.S., Vice-President, in the
The SECRETARY read a paper by Mr. J. B. HANNAY, Chair.
“On Calcium Sulphate.” The paper contains a descrip
tion of various double and triple salts containing Cason, After the names of the visitors had been announced, and which were deposited in the interior of pipes in a manuthe minutes of the previous meeting read and confirmed, factory. Solutions circulated through these pipes conthe following names were read for the first time :-Messrs. taining simultaneously K2SO4, Na2SO4, CaSO4, MgSO4, W. Hampton, J. Napier, D. W. Ladley, J. C. Leach, and I and K CrO4, the last being in by far the largest proportion. W. H. Ellis. Messrs. Walter Charles Davis, John Clark, , The temperature of the liquids varied from 40° to 80° C. Frank Herbert Marshall, John Wood, Griffith Jones, B.A., In one instance most of the incrustation consisted of John Falconer King, and Charles Cecil Capel were elected CaK2(SO4)2 + H20, but there were also present two other Fellows of the Society by ballot, after their names had compounds, CaS04,K2CrO4+H20 and CaSO4,2K2Cr04. been read for the third time.
They were both of a bright golden colour, resembling lead The first communication was by Prof. A. H. CHURCH, iodide,and very similar in appearance. By the action of water "On Colein.". This, the red colouring matter existing in they are decomposed, the potassium chromate dissolving out, the stems and leaves of the Coleus Verschafellii, was pre- and leaving calcium sulphate, but without any change in pared from the bruised stems by exhausting them with the form of the crystal. ' In another pipe, where there were cold alcohol, slightly acidulated with sulphuric acid, re- large quantities of the salt CaNa2(SO4)2, a salt having the moving the acid by barium carbonate, and concentrating formula CaSO4,Na2SO4,K,Cr04+H20, or some multiple by distillation. The various processes were tried for the of this, was found. The author has also made several purification of the red colouring matter, the best being to experiments to ascertain if the following series of comdissolve it in alcohol, precipitate with ether, again dis- pounds existed :solve in alcohol, and pour the solution into water, re
2CaSO4+4H20. peatedly washing the precipitate with water at 50° to 60°C.
2CaSO4+3H20. On analysis it gave numbers corresponding with the for
20a804+2H20. mula C10H100g: this was confirmed by the results obtained
CaSO + H2O. from the lead compound, C20H18Pb010. The latter was pre; The first of these is deposited when a solution of calcium pared by precipitating the colein with excess of lead sulphate is evaporated at 100° C. under the ordinary pres. acetate, both in alcoholic solution. It is of a dull indigoblue colour. Colein is insoluble in ether, only slightly sure, and the last by evaporation under a pressure of soluble in water, but readily in alcohol, yielding a solution, 20 pounds to the square inch. No definite results could
be obtained at intermediate pressures. On heating which is at first crimson, but fades rapidly, owing to a combination taking place between the alcohol and the Caso +4H20 (pure selenite) to 118° it begins to lose coluuring matter. On evaporating the nearly colourless water, at 150° the loss indicated the formation of
2CaSO4+H20. At 190° the last molecule of water is solution, or on adding an acid, the crimson colour is, driven off. By heating the selenite first at 118° to start however, restored. By gradually adding ammonia to a solution of colein, the colour is changed successively to tions were obtained of the existence of zČaSO4+3H20,
the dissociation, and then at 100° for a long time, indicapurple, violet, indigo, chrome green, and finally to greyish but none of the compound 2CaSW4+2H20. yellow. Stannic chloride gives a precipitate of a beautiful
Dr. H. E. ARMSTRONG said he had made some experiviolet colour when added to a strong alcoholic solution of ments with a view to ascertain if there was any relation colein. The author also described and exhibited the between the loss of water experienced by certain isospectra of colein, both in a pure state, and also when morphous salts under precisely similar circumstances. He submitted to the action of various reagents.
had found that at the ordinary temperature over sulphuric The Chairman having thanked Prof. Church for his acid the sulphates of zinc, magnesium, nickel, and iron interesting paper,
parted with their water of crystallisation in ratios repreA MEMBER said that when working with ivy he had ex
sented by the numbers—Zn, 7460; Mg, 2685; Ni, 1570; tracted a colouring matter from the pericarp. of the fruit, and Fe, 4015. With potash and chrome alums the ratios which appeared to be analogous, if not identical, with the colein of Prof. Church. Its colour was intensified by the and manganese gave-Co, 272; Ni, 032 ; and Mn, 210.
were-K 0865, and C 4625; the nitrates of cobalt, nickel, addition of acids, whilst alkalies, on the contrary, The Chairman having thanked the author for his paper, changed it. Mr. Grosjean, in reference to the author's remark as to
and Dr. Armstrong for his interesting observations,
Mr. G. S. JOHNSON read some" Additional Notes on the close resemblance between the colouring matter of Potassium Tri-iodide," consisting of a corrected determinathe grape and colein, stated that when determining the tion of the specific gravity of the crystals, which was value of red argols he had noticed that the colouring found to be 3.498. and the atomic volume, which is 1202. matter present gave a very sharp reaction with alkalies, The theoretical number, calculated on the supposition that almost as distinct in fact as litmus. In this case, however, | an atom of potassium unites with three of iodine without the yellowish tint produced by a slight excess of soda was condensation, is 122-2. again changed to red on the addition of an acid, whilst colein appears to be decomposed, as the colour, when once cember 21, when Mr. W. N. Hartley will give a paper
The meeting was then adjourned until Thursday, Dechanged by an alkali, does not come back.
entitled " A Further Study of Fluid Čavities." Dr. Otto Witt made a short verbal communication “On Phenylen-Diamin.” This was prepared by the action of reducing agents on dinitrobenzene, and is employed in NEWCASTLE-UPON-TYNE CHEMICAL SOCIETY. the manufacture of the browa dye known as “ Vesuvine."
General Meeting, October 26th, 1876. It may be obtained from the solution as a crystalline hydrochloride, after the removal of the lime by oxalic
The President in the Chair. acid. On distilling the hydrochloride with lime, the phenylen-diamin passes over. It is a colourless crystal. The minutes of the last meeting were read and conline substance, which, however, rapidly becomes dark l firmed.