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Apparatus for Estimating Free Oxygen.

PHYSICAL SOCIETY.

Ordinary Meeting, March 22, 1879.

Prof. W. G. ADAMS, President, in the Chair.

NEW Member Capt. Hastings R. Lees, R.N. Capt. ABNEY, R.E., F.R.S., read a paper" On Obtaining Photographic Records of Absorption Spectra." Absorption spectra have hitherto been recorded by the difficult process of hand copying; but the discovery by Capt. Abney of a silver salt sensitive to all rays in different degrees renders the photographic method available. The records thus obtained are photographs of the spectrum of the naked light of the source, and of that of the same light reduced by insertion of the absorbing material in its track, and these are taken parallel, so that the dark absorption lines can be readily compared. Examples of

these were thrown on the screen. This method can be used as a new weapon in attacking solar physics, and determining whether or not compound bodies exist in the sun. Absorption spectra to compare with the sun's can be got for compound bodies by burning the matter in question in a flame in front of the slit, and passing a bright light through the flame.

Prof. GUTHRIE, F.R.S., then read a paper "On the Fracture of Colloids," as illustrated by experiments on the breakage of glass plates either by pressure or heating at the centre or round the circumference. Circular plates of glass pressed at centre or circumference break in radial lines. However supported a plate breaks in the same fashion if heated in the same way. If heated in the middle the crack is peak-shaped, like an obelisk on a double pedestal, two cracks forming the outline, with sometimes a third down the middle. The two cracks unite before they reach the edge on one side, and (as afterwards pointed out by Prof. W. G. Adams) the three extremities of the two cracks all meet the edge at right angles to it. The crackage varies with the size and shape of the plates, the flame, and kind of glass; but the type is the same for all. Cracks cross each other. Prof. Guthrie defined a crack as the line where the ratio of cohesion to strain is least, and likened it to the lightning flash.

Mr. W. CHANdler Roberts, F.R.S., said that he had observed once a volute spiral crack in dried hydrated silicic acid, and recommended Prof. Guthrie to study cracks in agate, which is the most perfect colloid known.

NEWCASTLE CHEMICAL SOCIETY.

Mr. J. W. SWAN in the Chair.

THE minutes of the previous meeting were read and confirmed.

Mr. John Cliff was elected a member. The following names were read for the first time :-Mr. James C. Rollin, 1, St. Nicholas' Buildings, Newcastleupon-Tyne; Mr. Thomas Douglas, Blaydon Manure Works, Blaydon-on-Tyne; Mr. Alfred Poole, Bottle Works, Blaydon-on-Tyne; Mr. W. F. Vint, Chemical Works, Seaham Harbour.

The CHAIRMAN, in drawing attenion to the collection of apparatus sent for exhibition, alluded to the difficulty which had always been experienced in getting the meeting immediately preceding Christmas satisfactorily filled in the usual manner-a difficulty which had led to exhibitions of little novelties such as were then before the meeting, and to the passing the evening in a less formal and more social manner. The secretaries had been in correspondence with such friends as they thought likely to condtribute objects of interest, including Messrs. Aug. Bel and Co., from whom they had been hoping till the last day to receive M. Cailletet's apparatus for the condensation of

{CHEMICAL NEWS,

March 28, 1879.

gases, which in itself would have been ample attraction for the meeting; but, unfortunately for the Society, it was still in use at the Royal Institution, and in consequence could not be spared; but in the absence of this great attraction, there were yet objects that would repay examination, and he invited Mr. Starks to describe the mode of using the apparatus for estimating free oxygen in a mixture of gases, and the two forms of nitrometer. The following notes, descriptive of the apparatus, were read:

"Apparatus for Estimating Free Oxygen Volumetrically," by Messrs. MAWSON and SWAN.

The accompanying sketch represents a simple and convenient apparatus for the rapid and correct volumetric estimation of oxygen when mixed with other gases. It consists, as will be seen, of a measuring tube, A, holding from o to the three-way tap 100 c.c, and graduated in the

lower narrower portion into c.c. and tenths; of an absorption arrangement, B, which is a glass bell in which is placed a coil of copper gauze, suspended in an outer glass vessel which contains the absorbing liquid; a three-way tap, c, which serves to communicate between the measuring and absorption tubes, or with either and the external atmosphere; and of a globe, D, which serves the purpose of drawing the gas for examination into the measuring tube, and chasing it backwards and forwards between the measuring and absorption tubes. The solution used to absorb the oxygen is made of two parts of a saturated solution of chloride of ammonium and one part of liquid ammonia, s.g. 880. For an examination, the vessel, B, having been about two-thirds filled with the ammonium solution and sufficient water put into D to fill the measuring tube, expelling the air by the vertical outlet, c, the tap, C, is opened so as to make communication between A and B ; D is then lowered so as to fill the glass bell and tube

above it is as far as the tap with the ammonium solution,, A is now taken out of the spring clamp, violently shaken then close c on the side B, and open the vertical outlet ; D is then raised so as to fill the measuring tube with water up to the tap; the vertical outlet is now connected with the gaseous mixture to be examined, and by again lowering D the gas is drawn into the measuring tube to o, when exactly 100 c.c. will be present for examination; now turn c so as to make communication again between A and B, and chase the gas backwards and forwards by the raising and lowering of the glass vessel, D, two or three times, finishing by bringing the gas back to the measuring tube, and the absorbing solution to the original starting point; lastly, close the three-way tap altogether, and bring D down so that the two water levels in D and A coincide, when the reading of the liquid in a will give the percentage of oxygen that has been absorbed. By using other solutions it is obvious it may be used for the examination of other gases.

"Dr. Lunge's Nitrometer for Determination of Nitrous and Nitric Acids," by Messrs. MAWSON and SWAN.

for two minutes (no more is necessary), replaced in the clamp, and в adjusted, so that the levels of mercury of both tubes are equal, except that an allowance is made in B for the acid contained in A, 4th of the heigth of the latter being either allowed for as an addition to the mercury in B, or else being deducted from the barometrical pressure. After the temperature has become constant (quarter of an hour suffices for factory work, one hour for exact analyses), the volume of gas in A is read off (which can be done to c.c.) and reduced to o° and 760 m.m, in the usual way. Each c.c. at o° and 760 m.m. corresponds to 1'343 m.gr., NO=1701 m.gr., N203=2'417 m.gr. N2O5=3.805 m.gr., NO,Na, &c. Now D is opened so that a and c communicate, B is raised, and thus first the gas then the acid are driven into c, from whence the acid is run away by the lateral bore of D; everything is now ready for a new test.

“ Model of Modern Blast-Furnace," by P. A. Berkley. Mr. P. A. BERKLEY exhibited a model of a blast-furnace, The method of using is thus described by Dr. Lunge:- which he said appeared to give the most satisfactory results You will observed the measuring tube, A, holding 50 c.c., in working, producing about three times as much iron per divided inths, provided with a funnel, c, and a two-week as the old forms of furnace, and had not been surbore glass cock, D, hanging in an instantaneously-opening passed by furnaces of either larger or smaller dimensions. it had worked incessantly since 1872. The model was accompanied by the following note:

B

The model shows section through middle, with the various charges of iron ore, limestone, and coke, made to the scale of inch equal 1 foot. The counterpart of this furnace is at Jarrow. It is 85 feet high, 26 feet boshnearly 30,000 cubic feet capacity. It is blown by 5 tuyeres, 5 inches and 5 inches in diameter, with blast at a pressure of 4 lbs. and heated up to about 1200° F. The heat for the blast is raised from the waste gases from the furnace, as well as the steam for working the blast engine. This furnace is making 500 tons of pig-iron per week, in the making of which it consumes about 1750 tons of Cleveland ironstone, or other ores equivalent thereto, 587 tons of coke, and 300 tons of limestone. The furnace was erected in 1872, for Messrs. Palmer and Company, by Mr. Philip A. Berkley, the Company's Engineer and Blast-Furnace Manager.

A brief discussion followed, in which Messrs. Hill, Morrison, Berkly' and the Chairman took part.

(To be continued).

40

MOR

spring clamp; an elastic tube connects A with the plain tube, B, of equal size, sliding up and down in another clamp. First of all, B is placed so that its lower end is nearly at a level with D; mercury is poured into B till it has filled A and has got into C; D is turned so as to close the communication between A and B, and so run off the excess of mercury through the lateral bore; B is lowered in its clamp, and I c.c. of the nitrous vitriol, &c., to be tested is introduced into c by means of an accurate pipette. By carefully turning D, the acid is sucked into A without any air following, and c is rinse out by a few c.c. of pure acid, run into A in the same wa

NOTICES OF BOOKS.

Ozone in Relation to Health and Disease. (An Address delivered before the Congress of the Sanitary Institute of Great Britain, held at Stafford, 1878.) By HENRY DAY, M.D. London: J. and A. Churchill.

In this Address the author gives us the history of the discovery of ozone, and notices the successive theories of Schoenbein, Williamson, and Odling concerning its nature. He then describes the pathological action of this form of oxygen, and reveals facts which will probably startle those who believe ozone and "ozonised" articles of food or of medicine to be universally beneficial. He describes the death of animals after exposure to ozonised air under symptoms closely resembling those of acute bronchitis. He considers that if present in excess in the atmosphere, catarrh, bronchitis, and even pneumonia would be its natural results. Whether there is ever such an excess as would involve these consequences is an open question. He feels also bound to admit, according to the researches of Dr. Moffat, that during "ozone periods " apoplexy, epilepsy, vertigo, neuralgia, and diarrhoea are more frequent. Further investigations in this direction are imperatively needed, but what has been said may serve as a caution to dabblers in science who keep an ozone apparatus in action in their sitting-rooms as a prophylactic against diseases in general.

134

Chemical Notices from Foreign Sources.

{CHEMICAL NEWS,

March 28, 1879

The absence or the deficiency of ozone has been, per Any of your readers can try this by procuring samples of haps, too hastily laced in connection with zy motic Coleman's and Glenfield's starch weigh equal quantities, disease. But that such a connection exists in case of and boil with equal quantities of water and starch two cholera can scarcely be doubted. The author shows that pieces of cloth of equal size, without squeezing out the in 1864 in the Bombay Presidency, cholera was in its excess of starch, and dry; the touch will be able to determine greatest ascendancy when ozone was either wanting or at which is the stiffest. Mr. Thompson says: " and weight its minimum; that the disease showed a most marked for weight the farina which possesses the least tenacity' decrease when ozone was registered as increasing, and would produce the greatest stiffness, because the thinner when at its maximum the epidemic ceased altogether if the sample beils the more easily will the solid matter be the maximum continued for any time. Similar results able to enter the fibre, and it will enter in greater quanwere obtained at Strassburg in 1854 and 1855, and the tity." In the process of sizing when the yarn has passed experiments of Mr. Glaisher and of Dr. Moffat give con- through the size trough and got saturated with the size firmatory testimony. Whether there may be other causes (say starch) it passes between two rollers, which squeeze in operation in addition to deficiency of oxygen is still out the excess of size. Now, although the thinner doubtful. As a disinfectant the author pronounces it the sample may enter the fibre more readily and in greater best, safest, and least objectionable known. That it may quantity than the more solid, yet in passing through the kill disease-germs-whatever they may be--is no doubt rollers the thinner sample will be squeezed out in greater highly probable from its action on the superior animals; quantity and more readily than the thicker sample, and but the question arises, Which will be killed first? We as a consequence weight for weight the sample with the are somewhat suprised at finding in this address no refer-greatest tenacity will give the stiffest cloth, and what the erce to the well known and justly admired work of Dr. manufacturer has found out by experience is correct in C. B. Fox. theory, and Mr. Thompson and not my reasoning is fallacious.-I am, &.,

CORRESPONDENCE.

THE INSTITUTE OF CHEMISTRY.

To the Editor of the Chemical News.

SIR, The long time that elapsed between the date of the Conference and the issue of the report to the members of the Institute, as alluded to by your correspondent "An Appeased Pronicter," was caused chiefly by the decision to send it cut together with the annual report of the Council.

The financial position of the Institute at the present time is excellent, but I fear few people would consider it to be such if the Council were to follow your correspondent's advice and "spend the large sum they have in hand," especially when it is remembered that our invest: ment in consols does not cover the Life Compositions and Entrance Fees received up to the present. I do not for an instant suppose that "An Appeased Promoter" desires this to be spent. A man who lives up to his income is a poor man, however large his income may be, and this saying applies to corporations as well as to individuals. If, however, your correspondent thinks that the Council has left anything undone which it ought to have done, and will send me any suggestions, I can safely promise that they

will have the most careful consideration from the Council.

In conclusion let me thank "An Appeased Promoter" for his frank reply, and at the same time to express a wish that he had not written anonymously, as it would have enabled me to have answered his first letter more satisfactorily, and have saved valuable space in these columns occupied by Yours, &c.,

CHAS. E. GROVES, Secretary. Somerset House Terrace, W.C., March 22.

TENACITY OF STARCH.

Exchange Chambers, Blackburn,
March 25, 1879.

GEORGE WHEwell.

TESTING OF GAS WATERS.

To the Editor of the Chemical News. SIR,-In the CHEMICAL NEWS, vol. xxxviii., p. 193, there is a short article by Mr. T. H. Davis, "On the Testing of Gas Liquors." To those who have many of these liquors to test any contrivance that would tend to abridge the labour and at the same time afford reliable results would be hailed as a boon, and Mr. Davis is much to be com. mended for his efforts in that direction. The usual commercial valuation of gas liquors by degrees in Twaddle's hydrometer is so unsatisfactory that it is quite time it was superseded by some better method, and I think the test proposed by Mr. Davis gives at any rate a more reliable indication of the real strength of gas liquor than the method usually employed. I have not, however, found that this test is sufficiently accurate to supersede the usual distillation process, and I am not sure that Mr. Davis intends it should do so.

I have recently had five gas liquors placed in my hands for examination, and below I give the results of analysis by the method proposed by Mr. Davis (A), and also by the process of distillation (B)–

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CHEMICAL NOTICES FROM FOREIGN
SOURCES.

NOTE.-All degrees of temperature are Centigrade, unless otherwis expressed.

To the Editor of the Chemical News. SIR,-In reply to Mr. Thompson's letter (CHEMICAL NEWS, vol. xxxix., p. 122) I beg to say that the method for determining the tenacity of starch is not intended to determine the tenacity of a sample of British gum or the relative tenacities of British gum and starches, but only to compare samples of starches with each other. When I devised the method I conducted some experiments on the starches Comptes Rendus Hebdomadaires des Séances, l'Académie de found in the market. I found that when equal weigh's of the different samples of starch were boiled with equa quantities of water and pieces of cloth of equal siz starched with the different samples, that those sample: which had the greatest tenacity gave the stiffest cloth,

des Sciences. No. 9. March 3, 1879.

Reply to M. Van Tieghem Concerning the Origin of the Amylobacter.-A. Tiécul.-The author points out that his words have been inaccurately quoted by M. Van Tieghem.

Emissive Power of Coloured Flames.-M. Gouy.—, A mathematical paper, not susceptible of useful abstraction. Absorption Spectra of Didymium and of Certain cther Substances Extracted from Samarskite.-J. L. Soret. The author has compared didymium chloride extracted by M. Marignac from samarskite with a sample from a different source. In the entire less refrangible part of the spectrum, from the red to the green, he finds no appreciable difference either in the colour or in the intensity of the rays, and the spectrum agrees very exactly with the figures in the work of M. Lecoq de Boisbaudran. In the blue and the indigo differences of intensity appear. Hence the author is led to the conclusion that the didymium from samarskite contains some foreign body. The same substance is present to a smaller extent in terbia, and less still in the didymium obtained from cerite. Action of Ammonium Sulphocyanide upon Monochloric Aceton.-T. H. Norton and J. Tcherniak.Instead of sulpho-cyan-aceton, as was expected, there was produced the sulphocyanide of a base, C4H6N2S.

Amidated Acids Derived from the a-Butyric and Isovaleric Acids.-E. Duvillier.-The acids described are the methyl-amido-isovaleric, the ethyl-amido-a-butyric, the ethyl-amido-isovaleric, the phenyl-amido-a-butyric, and the phenyl-amido-isovaleric.

platinum metals are precipitated with ammonia, the free chlorine is expelled, and the liquid is mixed with excess of ammonio-ferrous sulphate, the excess of which is determined by titrating back with permanganate.— Zeitschrift Anal. Chem., 18, 104.

Reactions of Bile Acids and their Detection in Urine.-A solution of the bile acids, if oxidised by the addition of ferric chloride, antimonic chloride, lead peroxide, barium peroxide with the addition of hydrochloric or sulphuric acid, especially if exposed to direct sunlight, passes through a variety of colours from yellow, red, vinous red, to blue and blue-violet. Similar colours are produced by the addition of stannous or antimonious chlorides along with sulphuric acid. Casali takes advantage of this play of colour for the detection of bile acids in urine. The urine is precipitated with sugar of lead and ammonia, the precipitate treated with ether and dilute hydrochloric acid, and the ethereal extract is drawn off and evaporated in three porcelain capsules at common temperatures. To the first residue are added barium peroxide and sulphuric acid; to the second tin crystals and sulphuric acid; and to the third antimonious chloride and sulphuric acid.-Zeitschrift Anal. Chem., 18, 128.

Examination of Water for Bacteria.-Himly fills a flask, previously washed out first with hot concentrated sulphuric acid and then with the water in question, threequarters full of the water, and adds a little solution of a large quantity of water. meat-extract, prepared by boiling extract for fifteen minutes The flask is then stoppered and heated to 98° F. on the sand-bath. Bacteria, if present, surface of the water. increase rapidly, occasioning a turbidity and a film on the The experiment requires about twenty-four hours. Distilled water similarly treated shows no turbidity.-Zeitschrift Anal. Chem., 18, 117.

Influence of Oxygen on Alcoholic Fermentation as Produced by Beer Yeast.-A. Béchamp.-Oxygen was found to exercise a favourable influence upon the produc-in tion of alcohol. The quantity of acetic acid seems to depend much more on the temperature and on the nature of the yeast than on the oxygen. In short, the oxygen seems to act as a stimulus, under the influence of which the life of the yeast and the changes of its matter are more active. In a second set of experiments it was proved that the oxygen was actually absorbed.

Chemiker Zeitung.
No. 2, 1879.

Detection of Chromates and Free Chromic Acid. To detect mono-chromate along with bichromate add to a few c.c. of the boiling solution a drop of a moderately concentrated solution of manganese sulphate. In presence of monochromate a blackish brown precipitate is formed. Bichromate in monochromate is detected by adding to a boiling solution of hyposulphite of soda an equal volume of a hot solution of the chromate in question. A brown precipitate or a distinct turbidity proves the presence of bichromate. The precipitate is chromic peroxide. Free chromic acid in a solution of bichromate is detected by adding solution of iodide of potassium and agitating with sulphide of carbon, which is coloured a deep purple by the liberated iodine.—Zeitschrift Anal. Chem., 18, 78.

Action of Animal Charcoal on Salts.-Many salts, on filtration through animal charcoal, are held back more or less completely, or decomposed so that a part of the acid runs through, while the rest, in combination with the whole of the base, is retained by the charcoal.-Zeitschrift Anal. Chem., 18, 97.

No. 3, 1879.

Dr. J. Volhard has been appointed Professor of Chemis try at the University of Erlangen, as successor to the late Gorup-Besanez.

A. Podewils proposes to convert focal matters into poudrette by treatment with snioke, either of wood or coal

Determination of Ferrous Oxide in Silicates.

Dölter recommends the following process:-The finely pulverised mineral is covered with sulphuric acid and hydrofluoric acid in a platinum crucible set upon an iron plate. Over the plate is inverted a high beaker, whose edge fits into a groove made in the margin of the plate, and made air-tight by means of mercury or sand. From above, through a hole in the bottom of the beaker, a tube is passed to just over the crucible, and introduces a constant stream of carbonic acid. The whole apparatus is heated on the sand-bath, and the hydrofluoric acid escapes through the hole in the bottom of the beaker.— Zeitschrift Anal. Chem., 18, 50.

No. 4, January 23, 1879.

Determination of Sulphites and Hyposulphites.If both salts are present together in solution, it is necessary to find the quantity of iodine which a part of the liquid requires if mixed with acetic acid; and the quantity of sulphate of baryta which an equal part of the solution yields after complete oxidation with bromine. Two equations are thus obtained with two unknown quantities. If a sulphate is also present its quantity is ascertained by adding to the liquid bicarbonate of soda, passing a current A Contribution to the Fat-Industry.-Dr. B. Terne. of carbonic acid through the liquid, heating after expul--The author speaks of the application of the vapour of sion of the air, and after the addition of hydrochloric benzol in America for extracting oils and fats, not merely acid in excess concentrating to quarter its volume. The from wool and offal, but from bones, hoofs, &c. The fat sulphurous acid being thus expelled the sulphur is filtered of swine he remarks is apt to contract an objectionable off, and the sulphuric acid in the filtrate is determined in colour. The chief difficulty is the removal of the characthe ordinary manner.-Zeitschrift Anal. Chem., 18, 79. teristic odour of benzol. He has tried the action of benzol vapour upon tallow-greaves which had been previously submitted to hydraulic pressure of 10,000 to 12,000 lbs. per square inch, and obtained from 8 to 10 per cent of fat. The new Sanitary Office at Gera carefully examines all meat for Trichinæ.

Separation of Gold and Silver.-The metal is alloyed with 5 to 8 parts of zinc, for which the heat of a Bunsen burner is sufficient. The alloy is dissolved in nitric acid, when gold (with platinum and tin as stannic oxide if present) remains undissolved. To separate gold from platinum and tin they are dissolved in aqua regia, the

Dr, Upmann, in consequence of some experiments upon

136

Chemical Notices from Foreign Sources.

dogs, pronounces oxalic acid harmless. Dr. Pfeiffer, in reply, points out that the stomach and intestines of dogs generally contain considerable quantities of calcium phosphate by which the oxalic acid would be converted into calcium oxalate, an inoffensive salt.

According to the Revue Industrielle a metal has been extensively produced in France, which is a combination of iron and steel. The two metals are run separately into a mould divided into two parts by a thin plate of sheet iron, when the whole becomes welded together. The new metal is particularly adapted for armour-plating, anchors, and safes.

According to Fischer, in the Metallarbeiter, petroleum is adulterated with so-called solar oil, which occasions the dull yellow colour of the ordinary oil and its yellowish flame.

No. 5, January 30, 1879.

Dr. H. Geissler, of Bonn, died on the 26th ult. His establishment for the construction of physical apparatus will probably be carried on by Franz Müller, who has been for twenty-five years first his pupil and afterwards his

assistant.

Lead, in dangerous quantities as an ingredient in the so-called tinning of sauce-pans, &c., has been detected by Dr. Brockhoff, of Magdeburg.

Dr. Wolff, inspector of factories for the Düsseldorff circle, has introduced a respirator for the use of men employed in white-lead works, lead smelting establishments, &c. The results are said to be satisfactory.

Test for Olive Oil. Poutet proposes the following method:-Nitrate of mercury (doubtless mercurous) is prepared by dissolving 6 grms. mercury in 75 grms. nitric acid at 38° to 46° B. in the cold. Next 96 grms. of the oil in question are mixed with 8 grms. of the mercurous nitrate and shaken together every ten minutes for two hours. After being allowed to settle for twelve hours, if the oil was pure the elaidin thus formed is pale yellow and quite solid. In adulterated samples the elaidin is orange or dark red, and only partially or not at all solid. To detect the presence of the oil of sesame 2 parts of the sample are shaken up at a temperature of 20° to 25° with I part of pure hydrochloric acid at 22° B., in which 0.05 to o'r grm. of sugar has been previously dissolved. After standing for some time the oil separates from the acid, and if sesame is present assumes a rose colour. The more intense this colour the greater is the quantity of the impurity.

No. 6, February 6, 1879.

A. G. Moser, of Graben, in Thun, is said to have invented a remedy for the phylloxera, which completely eradicates it without injury to the vines.

T. Salzer has observed that sal-ammoniac and calcic hypochlorite react upon each other so violently as to give rise to an explosion.

Schneider, on preparing sodic hypochlorite by passing chlorine-gas into sodic bicarbonate, observed a rose colouration, which he traces to the presence of sodic ferrate.

No. 7, February 13, 1879.

A curious toxicological case is reported from Hamburg. The body of a man who died in 1867 was taken for examination. It was thought necessary to determine arsenic not merely in the corpse in question, but in the soil of the churchyard at different distances from the coffin, and also in the body of another man who had been subsequently buried in the same grave. This latter body was perfectly free from arsenic, which, however, was found in the first corpse in ample fatal quantity (o'24 grm.), whilst in the lid of the coffin and in the adjacent very minute quantities were traced. Hence the conclusion was fairly drawn that the man in question had been poisoned with arsenic, and that a portion of the poison had been gradu

CHEMICAL NEWS, March 28, 1879.

ally transferred from his body to the wood of the coffin and the adjacent soil.

Determination of Iron in Grain and other FoodPlants.- Eliosoff proposes the following method for the determination of iron in presence of phosphoric acid. The ash is evaporated to dryness with nitric acid, again taken up in dilute nitric acid, filtered, concentrated, precipitated with the molybdate of ammonia; the precipitate is digested upon the filter for some time with citric acid, the filtrate evaporated to dryness, the residue ignited, and re-dissolved in hydrochloric acid with the aid of heat, and the liquid separated by filtration from the liberated molybdic acid. In the filtrate the iron is determined as usual.-Journ. de Pharm. et de Chemie.

No. 8, February 20, 1879.

Dichromates.-Schulerud has prepared the dichromates of silver, thallium, and lithium, but has not succeeded in obtaining corresponding salts of lead, barium, and mercury. He concludes that univalent metals only yield dichromates, and argues hence to the univalence of lithium.

Detection of Salicylic Acid in Beer.-Blas recommends to drink the beer and in about three hours to test 20 c.c. of the urine with ferric chloride in the usual manner, as the reaction is about five times more delicate in urine than the original beer.

Extraction of Animal Pigments.-C. Méhu separates colouring matters from animal fluids by the addition of ammonium sulphate. In this manner he readily isolates the pigments of pathological urines, fœcal matter, bile, serous liquids, &c.

Formation of Mannite in Beer.-The formation of

mannite is always a mark of the want of cleanliness, and is particularly promoted by decaying wood. In such cases the sugar present enters not into the alcoholic but the mucic fermentation.

Moniteur Scientifique, Quesneville.
January, 1879.

Critical Examination of a Posthumous Work by Claude Bernard on Alcoholic Fermentation.-M. Pasteur.-This is merely the reproduction in full of a paper read before the Academy of Sciences, Nov. 25, 1878.

Causes of Death in Carbuncular and Septicemic Affections.-M. Colin.-According to the author's views there is a death by the blood resulting from the inaptitude of this liquid to maintain the life of the cells and of the other anatomical elements. This type of death must be added to those characterised by Bichat, and is probably common to a great number of maladies, the carbuncular, the putrid, the typhic, and the pestilential.

Chemical Composition of Yeast.-M. Nægeli.-In this lengthy paper the author ascribes to bottom-yeast the following chemical composition :—

Cellulose and vegetable mucilage, forming the
cellular membrane

Proteic matters-(a) In the state of albumen
(b) In state of phosphorous compounds
Peptones, precipitable by sugar of lead
Fatty matters

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Under the extractive matters are included small quantities of invertine, leucine, and grape-sugar; still smaller quantities of glycerin, succinic acid, cholesterin, guanin, xanthin, sarkin, probably of inosite and traces of alcohol.

Alkaloids of Veratrum,-A. Tobien.-Taken fro the American Journal of Pharmacy, 1878, No. 3, p. 12

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