ANALYTICAL CHEE?I1ISTRY. 77 A n a1 y t i c a1 C h e m i s t r y. Colorimetric Experiments. By J. BOTTOMT~EI- ( Ch e m . News, 38, 191-193). -Experiments were made t o determine, if possible, the amount of colouring matter in a liquid by compaiison with a, standard liquid. White disks were sunk in two equal cylinders, the one containing the standard liquid, the other that to be tested, i t being thought that the dept’h of the disk would be inversely as the quantity of the colouring matter present. It appears, however, thzt the method cannot, be practically employed, owing mainly to the diffi- culty of detecting the exact shades of colour. Schutzenberger’s Process for the Volumetric Estimation of Oxygen in Water. By C. c. HUTCHINSON (Chem. News, 38, 184--187).-1n water containing sewage, oxygen is present in quan- tities below the normal, but the quantity increases as the sewage de- creases; in deep well-water, however, containing no sewage, it is stated there is an almost total absence of oxygen ; this may be owing to its having already been removed by organic matter during its passage through the strata.To settle the question whether oxygen is or is mot an indication of the purity of water, the author was anxious to employ some method more rapid than that of Bunsen’s for the de- termination of the amount of oxygm present, but it appears by the experiments that the method which he proposed to ernploy is scarcely accurate enough, although it admits of grea.t rapidity, and is morc suited for a small quantity than f o r a large quantity of water: it is also valuable as R preliminary experiment.The method consists in E. W. P.75 ABSTRACTS OF CHEMICAL PA4PERS. adding a known volume of the water to a solution capable of bein9 oxidised, accompanied by a change of colour, by the oxygen contained in the water. The extent to which this has occurred is then deter- mined by the addition of a reducing agent, which reduces it to its former condition. This last solution is standardised in terms of the oxygen it is capable of taking up ; and from the amount used in the experiment, the volume of oxygen present is calculated. The reducing agent employed is sodium hyposulphite, made by passing sulphurous anhydride to saturation into a solution of soda, sp. gr. 1.4, diluted to sp. gr. 1.34, and reducing the product with powdered zinc : milk of lime is then added, which precipitates the zinc and also renders the liquid less absorbent of free oxygen.The liquid by which the change of colour detects the completion of the process is either sodium sulphindigotat,e, or Coupier's aniline blue ; 10 grams of the indigotate are dissolved in 1 litre of water. An ammoniacal solution of copper sulphate con- taining 4.46 grams per litre is used to standardise the above solutions. The estimations must all be made in an atmosphere of hydrogen. The process for determining the oxygen present is fully described, as well as the method of standardising the solutions. Appendix to the Estimation of Carbonic Acid in the Air. By W. HESSE (Zeitschr. j'. Biologie, 14, 29--33).--Having given some additional directions with a view to avoid the introduction of carbonic acid from the outer air along with the baryta-water, the author re- commends the following method for ordinary purposes :-A solution of oxalic acid of *5727 gram to the litre is prepared, and baryta-water, of which 10 C.C.neut,ralise from 20 to 25 of this solution of oxalic acid, and volumes of air of about half a litre are used. According to whether 4 to 5 per mil. or more of carbonic acid are expected, 10 to 20 C.C. of baryta-water are added. The pipette is inserted through an india- rubber stopper with two perforations, the escape of air from the flask being regulated by the finger on the second apertrlre. The flask is rapidly closed aftler removing the pipette. The numbers are often some- what too high. E.C. B. Quantitative Determination of Sulphur in Illuminating Gas. By POLECK and BIEFEL (Chem. Centr., 1878, 331).-A measured quantity of the gas to be examined is burned in air, and the products of the combustion drawn through an alkaline solution of bromine by means of a water aspirator. The sulphur is determined as barium sulphate. The gases examined by the authors were taken from t,he works a t Breslau, the experiments being made on the same day, and as rapidly one after the other as possible. The following results were obtained :- E. W. P. Sulphur in 1,000 litres of gas, 0.600 gram I n the retort house.. .......... Before the scrubbers .......... 0.540 ,, After passing the scrubbers.. .. 0.464 ,, After passing the condensers .. 0.440 ,, I n the finished gas.. .......... 0.276 ,, In the first four determinations, H,S is included ; and when CS, isANALYTICAL CHENISTRY. 71) separately determined in the finished gas, the residual sulphur may be considered as belonging to the so-called sulphuretted hydrocarbon, the smell of which resembles phenyl mustard-oil. J. M. T. Estimation of Nitric Acid as Ammonia. By E. A. GRETE (Deut. Chem. Ges. Ber., 11, 1557-1558).-Nitrates are completely reduced to ammonia by heating to redness with soda lime and a Estimation of Nitrous and Nitric Acids. By G. LUNGE (Diwgl. polyt. J., 228, 447-4501 .-Lange has constructed an a p paratus for determining the above acids, which is a modification of Watts’ apparatus described by Davis (Chem. News, 37, 4.5), and resembles Runte’s modification of Rauch’s gas burette.This im- proved form has no trough, arid requires but little more mercury than is necessary to fill the tube (about 830 grams) ; it is easily cleaned out after every operation, and has the advantage of the mercury not coming into direct contact with the worker. Lunge calls it a “ nitro- meter. ” D. B. xant hogenat e. w. c. w. Behaviour of Quartz with Microcosmic Salt. By E. LAUFER (Deut. Chem. GRS. Ber., 11, 935).-1n a former paper, the author de- scribed a method of separating quartz from admixtures with silicates by fusion with microcosmic salt, which it was then thought decom- posed silicates without attacking quartz. But further experiment has shown that the method cannot be relied upon, inasmuch as quartz ibelf, especially when finely powdered, is acted on by the fused salt.J. R. Testing and Valuing Gas Liquor. By T. H. DAVIS (Qheliz. News, 38, 193--195).-Gas liquor, or a crude solution of ammonia salts, is generally sold on the basis of its sp. gr., or on its degree (Twaddle). This test is, however, untrustworthy, although an indica- tion of the “ strength ” of the liquor is obtained. Now, as the ammonia is that for which the manufacturer contracts, i t is recommended to titrate the ‘liquor as follows :-Into it flask of about 300 C.C. capacity 10 C.C. of the sample to be tested are run in, and into this 15 C.C. of nornial sulphuric acid. The contents of the flask are then raised to boiling, a few drops of litmus added, and titrated back with normal soda. The niimber of C.C.of soda used are deducted from the 15 C.C. of acid em- ployed, the result multiplied by 17, and divided by the specific gravity of the liquor. The result thus obtained represents the percentage of ammonia contained in the liquor. Remarks on the Estimation of Calcium Sulphate in Beer. By H. M. WLLSON (Chem.. News, 38, 197).-Organic matter appears to interfere with the complete precipitation of the sulphuric acid in beer as barium sulphate. It is advisable, therefore, in the first instance to evaporate 100 C.C. of the sample to dryness, and after the addition of 0.5 gram potassium nitrate, to ignite the residue. E. W. P. E. W. P.SO ABSTRACTS OF CHEhlICAL PAPERS. Presence of Lead in Bismuth Subnitrate. By CHAPIUS and JANNOSSIER (Conyt. rend., 87, 1G9--171).--Carnot has shown that a11 samples of bismuth subnitrate of commerce contain lead; some- times in qiiantities dangerous for public safety.The authors of the present pxper propose the followinq method for the quantitative detec- tion of the lead. The bismuth nitrate to be examined is boiled with caustic soda and n small quantity of potassium chromate, the residue, after boiling, being thrown upon a filter. To the filtered liquid, acetic acid is added until the solution is j u s t acid, when a yellow precipitate is produced, more or less pronounced, according t o the amount of lend present. For & an abundant precipitate is obtained ; for the cloudiness of the liquid is distinct, and a dcposition very soon takes place in the form of a precipitate adhering to the sides of the tube ; lead chromate is slightly soluble in the mixture of sodic acetate and acetic acid ; smaller quantities could be detected if the weight of sub- stance used was increased.After mentioning that both calcium phosphate containing silica or alumina, and also impure soda interfere with the reaction, he describes the following quantitative method similar to that described for the qualitative detection. About 10 grarns of the bismuth nitrate are used, care being taken to wash the chromate of bismuth with a mixture of potassium chromate and sodium hydrate, first by decantation, and then on the filter until the filtrate is no lbnger rendered turbid by acetic acid in excess. The filtrate is now boiled, supersaturated with acetic acid, allowed to stmd 24 hours, and filtered.The precipitate is then washed with water slightly acidulated by acetic acid, dried a t 100" and weighed. The weight, found, multiplied by 0.6408, gives the weight of lead contained in the 10 grams of substance. Estimation of Nitrogen in Organic Bodies. By E. A. GRETH (Deut. Chew,. Ges. Ber., 11, 1558).-In estimating the nitrogen in horn, leather, and wool refuse, the author advocates dissolring the substance in warm concentrated sulphuric acid before heating with soda-lime. Higher results are obtained than by the ordinary pro- cess. w. c. w. -___ ;Idoo shows only slight cloudiness, often appearing only on cooling, as J. M. T. New and Rapid Process for the Analysis of Milk. By A. ADAM (Compt. relid., 87, 290-291) .-The analysis is performed by means of an apparatus consisting essentially of a glass tube of about 40 C.C.capacity, provided with a stopper a t the top, expanded in the middle, and tapered off a t the bottom, which is closed by a glass stopcock. Into this appai-atus is introduced 10 C.C. of alcohol of 75", containing of its volume of sodic hydrate ; then 10 C.C. of milk, which must be neutral ; and finally, 12 C.C. of pure ether. The liquids are shaken together, and allowed to remain a t rest for five minutes, when they separate into two layers: the clear upper one con- tains all the butter; the lower, the lactose and case'in. The butter contained i n the former is estimated by eraporating and weighing, allowing 1 centigram for a little case'in, &c., which may be con-ANALYTICAL CHENISTRY.81 tained in the liquid, or eliminating this by re-solution in ether. In the liquid first drawn off, the lactose and casein are estimated by making up to 100 C.C. with distilled water, and adding 10 drops of acetic acid ; the casein then separates, and after having been removed by filtration, is pressed between folds of bibulous paper, dried, and weighed. The filtrate contains the salts of the milk, the acetate of sodium formed, and the lactose. The latter is estimated by means of Fehling's cupro-potassic liquid. All these operations are easily per- formed in an hour and a half; and if, a t the commencement? 10 C.C. of the milk acidulated with two drops of acetic acid are set to evapo- rate, the weights of dry residue, ash, and water may be obtained within the same time.R. R. Butter Analysis. By H. HAGER (Chew. Centr., 1878, 333-334). -1. 20.0 parts of the butter to be analysed, together with 3.0 to 4.0 parts of pure sodium chloride, are placed in a weighed glass vessel, and the whole is weighed and heated to 50-80" in a water-bath, when the fatty part forms a yellowish layer on the top, whilst the water, casei'n, and salt remain at the bottom. Two portions of 5.0 parts of the clear fat are placed in glass flasks of about 12.0 C.C. for further investiga- tion, as described in 111. 11. Estiwation of nii'disture, Casein, a d Salt.-The fat is decanted as far as possible; then 10 C.C. of warm benzene are added and gently agitated with the liquid, so as to take up the rest of the fat. The vessel is t,hen allowed to stand in a warm place for half-an-hour, when the benzene is poured off and 10 C.C.more are added to remove the last traces of fat. The liquid is allowed to stand for half-an-hour longer in a warm place to remove the last traces of benzene, and the vessel and its contents are again weighed; this, after subtracting the 3 . 0 4 . 0 NaCl added, gives the weight the total moisture, casei'n, aud salt. The residue is then treated with hot water and filtered. Thc filtrate evaporated to dryness gives, after subtracting the NaCl added, the salt in the butter. 111. Snponijication of the Butter Fat.-To the 5 grams of fat in the flask, 20 C.C. of alcohol are added, and 10 C.C. of a freshly-prepared solution of 2.0 grams of pure caustic soda in 10.0 of distilled water; the whole is then agitated and heated to 50-60°, when the flask is corked and violently shaken.The alcohol prevents frothing. After a few moments' rest, small particles of fat are observed if the saponifica- tion is not complete. When this is the case, the flask is uncorked aud again heated ; recorked, wrapped in a towel, and shaken ; it is scarcely ever necessary to repeat the operation a third time. The author says that it takes about 6-8 minutes for complete saponification. IV. The warm soap-solution is poured into a large beaker, and the flask washed out with 45 per cent. alcohol. The solution is then warmed without boiling, so as to evaporate as much as possible of the alcohol ; 3-4 C.C. do not interfere with the following reactions. A little warm water is added, and then 20.0 of previously warmed dilute sulphnric acid (1 : 5 water), and stirred; water is then poured in until the level of the liquid is about 2 c.below the mouth of the beaker. Aft,er the fat has completely separated out in the water-bath or other The casein remains on the filter. VOL. XXXVI. 9a2 ABSTRACTS OF CHEXICAL PAPERS. warm place, 5.0 of perfectly dry white wax or paraffin are added, heated to melting, and the whole placed in a cool place to solidify, leaving the glass rod in a beaker. The evaporation of t'he alcohol is necessary on account of the solubility in an alcoholic solution of the fatty acids insoluble in water. V. As the fatty acids soluble in water require a large quantity of the latter. it is better to employ 20-23 per cent.alcohol, as it dissolves them readily without acting on the insoluble acids. After cooling, the glass rod, with the cake of fat adhering to it, is carefully lifted oiit, the water poured off and replaced by the alcohol described above, and the fat again put into the beaker and gently boiled for about eight minutes. After cooling, the liquid is poured off and the whole opera- tion repeated, when all the soluble fatty bodies will have been removed. VI. The cake is now dried by means of blotting paper, and removed from the rod into a small flat-bottomed dish, previously weighed, toge- ther with the particles of fat which may have adhered to the beaker; dried at 100-120", and weighed, the weight of the wax added being subtracted. VII. It is safe to assume that butter fat contains 88 per cent.of fatty acids insoluble in water. When the amount of acid found does not exceed 88 per cent., nothing but pure butter fat is present. When it, is between 88 and 89, the butter fat may have been adulterated with other fats. When this is the case, a wick should be impregnated with the fat, lighted, and blown out. If the well-known smell of a tallow- candle is not distinctly perceived, the butter may be considered to bequite pure. When the weight exceeds 89 per cent., the butter is certainly adulterated. J. M. T. By F. v. LEPEL (Deut. Chem. Ges. Ber., 11, 1552--1556).-Beetroot juice is used in colouring wines for the purpose of concealing the presence of " magenta." The absorption- bands of " magenta " are hidden by those of the beetroot ; but if a few drops of copper sulphate solution are added to the wine, the beetroot- bands gradually vanish, and the " magenta " spectrum becomes visible.To detect " magenta " in presence of an extract of tbe flowers of the vild poppy, Pupuver Rlmas, 1 drop of iodine solution (-01 gram per c.c.) is: added to the wine, before examination with the spectro- Detection of Wines Adulterated with Grape Sugar. By C. NEUBAUEE (Dh2gZ. poZyt. J., 229, 463-466).-After decolorising the wine, which, when examined in tubes 220 mm. long with Wild's large polaristrobometer, shows a slight dextro-rotation of 0.4 to 0.6" (1" Wild = 4,6043" Soleil = 2.89005" Ventzke-Soleil), 250 to 3.50 C.C. are concentrated until the salts begin to crystallise out. The concentrated solution is, after the addition of a sufficient quan- tity of pure aqimal charcoal, diluted to 50 c.c., and filtered.The filtrate, generally of a, faint yellow colour, shows with most wines a slight dextro-rotation in tubes 220 mm. long, which varies with pure Rhine, Haardt, and Markgrafler-wines, from the years 1874 to 1876 between 0.5 and 2". The 50 C.C. are next evaporated to R Adulteration of Wine. scope. w. c. w.ANALYTICAL CHEI1IISTRT. 83 syrupy mass on the water-bath, the residue being treated gradually and with careful stirring with a quantity of 90 per cent. alcohol, large enough to throw down all precipitable matter. After having allowed the mixture to stand for 6 to 8 hours, the alcohol is either poured off or filtered off, and the residue extracted with cold water.The solution is decolorised with animal charcoal and filtered. In all natural wines the dextro-rotatory substance is chiefly in this alcoholic precipitate. The alcoholic filtrate is evaporated h one-fourth of the volume originally added, and the cold solution treated gradually with four to six times its volume of ether, shaking the mixture the whole time. After standing, a more or less thick aqueous solution separates under the ether, which in wines containing potato-sugar contains the non-fermentable substances of these preparations, soluble in alcohol (amylin), and consequently shows a strong dextro-rotation. After removing the ether, the aqueous solution is diluted with water, warmed on the water-bath, to expel all ether, decolorised with animal charcoal, and the filtrate diluted according to the size of the observation-tube to the necessary volume.With pure natural wines of medium growths, which no longer contain unfermented sugar, the dextro-rotation of this aqueous solution of the ether precipitation from 250 to 350 C.C. of wine is, after discoloration and dilution to 30 C.C. either nil, as in most cases, or a t the most, 0.2" to 0.5". The tables given in the original paper show tjhat all wines having a rotation of 0.1" t o 0.3" to the right, may be regarded as perfectly pure. If, however, the dextro- rotation is 0.5" to O*Ci", it is more satisfactory to apply the abovc- described method. D. B. Alizarin Colouring Matters, and Green Aniline Colours. By H. W. VOGEL (Deut. C'henz. Ges. Bes., 11, l371-l374).-Alizarir~- bZue.-This body dissolves in water on addition of ammonia witch indigo-blue colour, and shows a two-sided absorption of the spectrum, which appeared considerably stronger in the red than in the dark blue, and no bands could be recognised.Supersaturated with nitric acid, the solution becomes brick-red, and exhibits an absorption similar to that of red litmus tincture with a dark shadow in the green. Amy1 alcohol extracts the colouring matter quickly from the acid solutio~i, but only with difficulty from the alkaline solution. Alcohol dissolvcs the colouring matter in the completely neutral condit'ion, with violet colour. Treated with ammonia, the solution becomes blue, like cupric sulphate solution, and exhibits in the concentrated state a continuous absorption of the red end of the spectrum, and on diluting with alcohol, a highly characteristic spectrum reaction for alizarin-blue is developed.This consists of three bauds, the weakest of which is on D, the second between d and C (daylight), and the third on the extreme limit of the red, and is perceptible only with the strongest lamp-light. Potash acts differently on the alcoholic alizarin-blue solution. It becomes of a beautiful green, and then absorbs on both sides, most stronglyat the red end of the spectrum, but without bands. The aqueous solution gives the same reaction. As regards detecting the colouring matter, it is best to warm the coloured fabric with dilute 9 2S4 ABSTRACTS OF CHELWCAL PAPERS. hydrochloric acid, extract the colouring matter with amyl alcohol, and treat this with alcohol and ammonia.AZiznrin-orarzge (nitro-alizarin) in alcoholic solution shows a strong extinction of the blue, and a weaker one of the green. With certain tlegrees of concentration bwo very indistinct bands are recognised in the green. With ammonia the solution becomes coloured reddish, and then shows a stronger absorption of the green. With nitric acid it becomes bright yellow, and gims a one-sided absorption of the blue. Potassium hydroxide colours the alcoholic solution a beautiful rose colour, and gives then a continuous extinction of the green from F to D, in which two bands appear. Aqueous solutions of the colouring matter with potash become yellowish-red, and show a homogeneous shade without bands in the green.The acid aqueous solution of the “ alizarin-orange ” is easily extracted with amyl alcohol, and then gives with alcohol and potash a definite spectral reaction. From coloured textures, it is extracted just as “ alizarin-blue ’’ is. Both “ iodine-green ” and metliylrosaniline picrate show in dilute alcoholic solution an absorption-band between d and C. ‘‘ Iodine- green ” shows further a weak band on the D line, which disappears on dilution. The concentrated alcoholic solutions of both colours diluted with water turn their absorption-band somewhat towards the green (difference from “aldehyde ” and “ malachite-green ”). A drop of nitric acid added to the alcoholic solution of the “iodine-green” effects no alteration in the bands (difference from “ aldehyde-green ”).The green picrate is tlirned bluer with nitric acid, and the bands widen towards the green. A drop of ammonia colours “iodine-green ” solution violet, with formation of a band on the D line. The green picrate does not show this reaction ; it becomes yellowish. By addition of ammonia to the nitric acid solutions of the colouring matter, the original colour and the spectral bands gradually return. Jfnlnchite-green, in its optical behaviour, exhibits striking resemblance to “ aldehyde-green,” but diff’ers from it in its chemical properties. The former dissolves much more easily in alcohol, and the solution appears bluer than that of “ aldehyde-green.” Dissolved in alcohol and suitably diluted, both give exactly the same spectrum. I n highly dilute solutions, one band appears on the d line, widening itself in con- centrated solution, and besides, a continuous absorption of the blue. The only difference between the two colours is that the “ aldehyde- green” weakens the red right and left from the absorption-band somewhat more strongly than “ malachite-green ; ” with the latter, the band appears, on the other hand, considerably darker.Although so similar in optical properties, the two colours differ decidedly in their behariour with acids. A drop of hydrochloric acid or nitric acid added to the alcoholic “ aldehyde-green ” effects no apparent, alteration of colour ; on the contrary, in the nitric acid solution a striking altera- tion of position of the absoibption-band to the right is remarked, whilst the band of the “ malachite-green ’’ does not suffer the least alteration. With ammonia, “ malachite-green ” is almost immediately decolorised.“ Aldehyde-green,” on the contrary, becomes gradually blue, with ap- pearance of three faint bands, of which the last lies in the extreme red, and can be recognised only by the aid of a very bright lamp-TECHNICAL CHEMISTRY. S .'i light; the second is between d and C, and the third and weakest on D. The colours are easily extracted froin the textures with alcohol, and can be determined in the solution by the prescribed reactions. w. s,ANALYTICAL CHEE?I1ISTRY. 77A n a1 y t i c a1 C h e m i s t r y.Colorimetric Experiments. By J. BOTTOMT~EI- ( Ch e m . News,38, 191-193). -Experiments were made t o determine, if possible,the amount of colouring matter in a liquid by compaiison with a,standard liquid.White disks were sunk in two equal cylinders, theone containing the standard liquid, the other that to be tested, i tbeing thought that the dept’h of the disk would be inversely as thequantity of the colouring matter present. It appears, however, thztthe method cannot, be practically employed, owing mainly to the diffi-culty of detecting the exact shades of colour.Schutzenberger’s Process for the Volumetric Estimation ofOxygen in Water. By C. c. HUTCHINSON (Chem. News, 38,184--187).-1n water containing sewage, oxygen is present in quan-tities below the normal, but the quantity increases as the sewage de-creases; in deep well-water, however, containing no sewage, it isstated there is an almost total absence of oxygen ; this may be owingto its having already been removed by organic matter during itspassage through the strata.To settle the question whether oxygen isor is mot an indication of the purity of water, the author was anxiousto employ some method more rapid than that of Bunsen’s for the de-termination of the amount of oxygm present, but it appears by theexperiments that the method which he proposed to ernploy is scarcelyaccurate enough, although it admits of grea.t rapidity, and is morcsuited for a small quantity than f o r a large quantity of water: it isalso valuable as R preliminary experiment. The method consists inE. W. P75 ABSTRACTS OF CHEMICAL PA4PERS.adding a known volume of the water to a solution capable of bein9oxidised, accompanied by a change of colour, by the oxygen containedin the water.The extent to which this has occurred is then deter-mined by the addition of a reducing agent, which reduces it to itsformer condition. This last solution is standardised in terms of theoxygen it is capable of taking up ; and from the amount used in theexperiment, the volume of oxygen present is calculated. The reducingagent employed is sodium hyposulphite, made by passing sulphurousanhydride to saturation into a solution of soda, sp. gr. 1.4, diluted tosp. gr. 1.34, and reducing the product with powdered zinc : milk of limeis then added, which precipitates the zinc and also renders the liquidless absorbent of free oxygen. The liquid by which the change of colourdetects the completion of the process is either sodium sulphindigotat,e,or Coupier's aniline blue ; 10 grams of the indigotate are dissolved in1 litre of water.An ammoniacal solution of copper sulphate con-taining 4.46 grams per litre is used to standardise the above solutions.The estimations must all be made in an atmosphere of hydrogen. Theprocess for determining the oxygen present is fully described, as wellas the method of standardising the solutions.Appendix to the Estimation of Carbonic Acid in the Air. ByW. HESSE (Zeitschr. j'. Biologie, 14, 29--33).--Having given someadditional directions with a view to avoid the introduction of carbonicacid from the outer air along with the baryta-water, the author re-commends the following method for ordinary purposes :-A solutionof oxalic acid of *5727 gram to the litre is prepared, and baryta-water, ofwhich 10 C.C. neut,ralise from 20 to 25 of this solution of oxalic acid,and volumes of air of about half a litre are used.According to whether4 to 5 per mil. or more of carbonic acid are expected, 10 to 20 C.C. ofbaryta-water are added. The pipette is inserted through an india-rubber stopper with two perforations, the escape of air from the flaskbeing regulated by the finger on the second apertrlre. The flask israpidly closed aftler removing the pipette. The numbers are often some-what too high. E. C. B.Quantitative Determination of Sulphur in IlluminatingGas. By POLECK and BIEFEL (Chem. Centr., 1878, 331).-Ameasured quantity of the gas to be examined is burned in air, and theproducts of the combustion drawn through an alkaline solution ofbromine by means of a water aspirator.The sulphur is determinedas barium sulphate. The gases examined by the authors were takenfrom t,he works a t Breslau, the experiments being made on the sameday, and as rapidly one after the other as possible. The followingresults were obtained :-E. W. P.Sulphur in 1,000 litres of gas,0.600 gram I n the retort house.. ..........Before the scrubbers .......... 0.540 ,,After passing the scrubbers.. .. 0.464 ,,After passing the condensers . . 0.440 ,,I n the finished gas.. .......... 0.276 ,,In the first four determinations, H,S is included ; and when CS, iANALYTICAL CHENISTRY. 71)separately determined in the finished gas, the residual sulphur may beconsidered as belonging to the so-called sulphuretted hydrocarbon,the smell of which resembles phenyl mustard-oil.J. M. T.Estimation of Nitric Acid as Ammonia. By E. A. GRETE(Deut. Chem. Ges. Ber., 11, 1557-1558).-Nitrates are completelyreduced to ammonia by heating to redness with soda lime and aEstimation of Nitrous and Nitric Acids. By G. LUNGE(Diwgl. polyt. J., 228, 447-4501 .-Lange has constructed an a pparatus for determining the above acids, which is a modification ofWatts’ apparatus described by Davis (Chem. News, 37, 4.5), andresembles Runte’s modification of Rauch’s gas burette. This im-proved form has no trough, arid requires but little more mercury thanis necessary to fill the tube (about 830 grams) ; it is easily cleaned outafter every operation, and has the advantage of the mercury notcoming into direct contact with the worker.Lunge calls it a “ nitro-meter. ” D. B.xant hogenat e. w. c. w.Behaviour of Quartz with Microcosmic Salt. By E. LAUFER(Deut. Chem. GRS. Ber., 11, 935).-1n a former paper, the author de-scribed a method of separating quartz from admixtures with silicatesby fusion with microcosmic salt, which it was then thought decom-posed silicates without attacking quartz. But further experiment hasshown that the method cannot be relied upon, inasmuch as quartzibelf, especially when finely powdered, is acted on by the fused salt.J. R.Testing and Valuing Gas Liquor.By T. H. DAVIS (Qheliz.News, 38, 193--195).-Gas liquor, or a crude solution of ammoniasalts, is generally sold on the basis of its sp. gr., or on its degree(Twaddle). This test is, however, untrustworthy, although an indica-tion of the “ strength ” of the liquor is obtained. Now, as the ammoniais that for which the manufacturer contracts, i t is recommended to titratethe ‘liquor as follows :-Into it flask of about 300 C.C. capacity 10 C.C.of the sample to be tested are run in, and into this 15 C.C. of nornialsulphuric acid. The contents of the flask are then raised to boiling, afew drops of litmus added, and titrated back with normal soda. Theniimber of C.C. of soda used are deducted from the 15 C.C. of acid em-ployed, the result multiplied by 17, and divided by the specific gravityof the liquor.The result thus obtained represents the percentage ofammonia contained in the liquor.Remarks on the Estimation of Calcium Sulphate in Beer.By H. M. WLLSON (Chem.. News, 38, 197).-Organic matterappears to interfere with the complete precipitation of the sulphuricacid in beer as barium sulphate. It is advisable, therefore, in the firstinstance to evaporate 100 C.C. of the sample to dryness, and after theaddition of 0.5 gram potassium nitrate, to ignite the residue.E. W. P.E. W. PSO ABSTRACTS OF CHEhlICAL PAPERS.Presence of Lead in Bismuth Subnitrate. By CHAPIUS andJANNOSSIER (Conyt. rend., 87, 1G9--171).--Carnot has shown thata11 samples of bismuth subnitrate of commerce contain lead; some-times in qiiantities dangerous for public safety.The authors of thepresent pxper propose the followinq method for the quantitative detec-tion of the lead. The bismuth nitrate to be examined is boiled withcaustic soda and n small quantity of potassium chromate, the residue,after boiling, being thrown upon a filter. To the filtered liquid, aceticacid is added until the solution is j u s t acid, when a yellow precipitate isproduced, more or less pronounced, according t o the amount of lendpresent. For & an abundant precipitate is obtained ; for thecloudiness of the liquid is distinct, and a dcposition very soon takesplace in the form of a precipitate adhering to the sides of the tube ;lead chromate is slightly soluble in the mixture of sodic acetate andacetic acid ; smaller quantities could be detected if the weight of sub-stance used was increased.After mentioning that both calcium phosphate containing silica oralumina, and also impure soda interfere with the reaction, he describesthe following quantitative method similar to that described for thequalitative detection.About 10 grarns of the bismuth nitrate are used, care being takento wash the chromate of bismuth with a mixture of potassium chromateand sodium hydrate, first by decantation, and then on the filter until thefiltrate is no lbnger rendered turbid by acetic acid in excess.Thefiltrate is now boiled, supersaturated with acetic acid, allowed to stmd24 hours, and filtered. The precipitate is then washed with waterslightly acidulated by acetic acid, dried a t 100" and weighed.Theweight, found, multiplied by 0.6408, gives the weight of lead containedin the 10 grams of substance.Estimation of Nitrogen in Organic Bodies. By E. A. GRETH(Deut. Chew,. Ges. Ber., 11, 1558).-In estimating the nitrogen inhorn, leather, and wool refuse, the author advocates dissolring thesubstance in warm concentrated sulphuric acid before heating withsoda-lime. Higher results are obtained than by the ordinary pro-cess. w. c. w.-___ ;Idoo shows only slight cloudiness, often appearing only on cooling, asJ. M. T.New and Rapid Process for the Analysis of Milk. By A.ADAM (Compt. relid., 87, 290-291) .-The analysis is performedby means of an apparatus consisting essentially of a glass tube ofabout 40 C.C.capacity, provided with a stopper a t the top, expandedin the middle, and tapered off a t the bottom, which is closed by aglass stopcock. Into this appai-atus is introduced 10 C.C. of alcoholof 75", containing of its volume of sodic hydrate ; then 10 C.C. ofmilk, which must be neutral ; and finally, 12 C.C. of pure ether. Theliquids are shaken together, and allowed to remain a t rest for fiveminutes, when they separate into two layers: the clear upper one con-tains all the butter; the lower, the lactose and case'in. The buttercontained i n the former is estimated by eraporating and weighing,allowing 1 centigram for a little case'in, &c., which may be conANALYTICAL CHENISTRY. 81tained in the liquid, or eliminating this by re-solution in ether.Inthe liquid first drawn off, the lactose and casein are estimated bymaking up to 100 C.C. with distilled water, and adding 10 drops ofacetic acid ; the casein then separates, and after having been removedby filtration, is pressed between folds of bibulous paper, dried, andweighed. The filtrate contains the salts of the milk, the acetate ofsodium formed, and the lactose. The latter is estimated by means ofFehling's cupro-potassic liquid. All these operations are easily per-formed in an hour and a half; and if, a t the commencement? 10 C.C.of the milk acidulated with two drops of acetic acid are set to evapo-rate, the weights of dry residue, ash, and water may be obtainedwithin the same time.R. R.Butter Analysis. By H. HAGER (Chew. Centr., 1878, 333-334).-1. 20.0 parts of the butter to be analysed, together with 3.0 to 4.0parts of pure sodium chloride, are placed in a weighed glass vessel, andthe whole is weighed and heated to 50-80" in a water-bath, when thefatty part forms a yellowish layer on the top, whilst the water, casei'n,and salt remain at the bottom. Two portions of 5.0 parts of the clearfat are placed in glass flasks of about 12.0 C.C. for further investiga-tion, as described in 111.11. Estiwation of nii'disture, Casein, a d Salt.-The fat is decanted asfar as possible; then 10 C.C. of warm benzene are added and gentlyagitated with the liquid, so as to take up the rest of the fat. Thevessel is t,hen allowed to stand in a warm place for half-an-hour, whenthe benzene is poured off and 10 C.C. more are added to remove thelast traces of fat.The liquid is allowed to stand for half-an-hourlonger in a warm place to remove the last traces of benzene, and thevessel and its contents are again weighed; this, after subtracting the3 . 0 4 . 0 NaCl added, gives the weight the total moisture, casei'n, audsalt. The residue is then treated with hot water and filtered. Thcfiltrate evaporated to dryness gives, after subtracting the NaCl added,the salt in the butter.111. Snponijication of the Butter Fat.-To the 5 grams of fat in theflask, 20 C.C. of alcohol are added, and 10 C.C. of a freshly-preparedsolution of 2.0 grams of pure caustic soda in 10.0 of distilled water; thewhole is then agitated and heated to 50-60°, when the flask is corkedand violently shaken.The alcohol prevents frothing. After a fewmoments' rest, small particles of fat are observed if the saponifica-tion is not complete. When this is the case, the flask is uncorked audagain heated ; recorked, wrapped in a towel, and shaken ; it is scarcelyever necessary to repeat the operation a third time. The author saysthat it takes about 6-8 minutes for complete saponification.IV. The warm soap-solution is poured into a large beaker, andthe flask washed out with 45 per cent. alcohol. The solution is thenwarmed without boiling, so as to evaporate as much as possible of thealcohol ; 3-4 C.C. do not interfere with the following reactions. Alittle warm water is added, and then 20.0 of previously warmed dilutesulphnric acid (1 : 5 water), and stirred; water is then poured in untilthe level of the liquid is about 2 c.below the mouth of the beaker.Aft,er the fat has completely separated out in the water-bath or otherThe casein remains on the filter.VOL. XXXVI. a2 ABSTRACTS OF CHEXICAL PAPERS.warm place, 5.0 of perfectly dry white wax or paraffin are added,heated to melting, and the whole placed in a cool place to solidify,leaving the glass rod in a beaker. The evaporation of t'he alcohol isnecessary on account of the solubility in an alcoholic solution of thefatty acids insoluble in water.V. As the fatty acids soluble in water require a large quantity ofthe latter. it is better to employ 20-23 per cent.alcohol, as it dissolvesthem readily without acting on the insoluble acids. After cooling, theglass rod, with the cake of fat adhering to it, is carefully lifted oiit,the water poured off and replaced by the alcohol described above, andthe fat again put into the beaker and gently boiled for about eightminutes. After cooling, the liquid is poured off and the whole opera-tion repeated, when all the soluble fatty bodies will have been removed.VI. The cake is now dried by means of blotting paper, and removedfrom the rod into a small flat-bottomed dish, previously weighed, toge-ther with the particles of fat which may have adhered to the beaker;dried at 100-120", and weighed, the weight of the wax added beingsubtracted.VII.It is safe to assume that butter fat contains 88 per cent. offatty acids insoluble in water. When the amount of acid found doesnot exceed 88 per cent., nothing but pure butter fat is present. Whenit, is between 88 and 89, the butter fat may have been adulterated withother fats. When this is the case, a wick should be impregnated withthe fat, lighted, and blown out. If the well-known smell of a tallow-candle is not distinctly perceived, the butter may be considered tobequite pure. When the weight exceeds 89 per cent., the butter iscertainly adulterated. J. M. T.By F. v. LEPEL (Deut. Chem. Ges. Ber.,11, 1552--1556).-Beetroot juice is used in colouring wines for thepurpose of concealing the presence of " magenta." The absorption-bands of " magenta " are hidden by those of the beetroot ; but if a fewdrops of copper sulphate solution are added to the wine, the beetroot-bands gradually vanish, and the " magenta " spectrum becomes visible.To detect " magenta " in presence of an extract of tbe flowers of thevild poppy, Pupuver Rlmas, 1 drop of iodine solution (-01 gramper c.c.) is: added to the wine, before examination with the spectro-Detection of Wines Adulterated with Grape Sugar.By C.NEUBAUEE (Dh2gZ. poZyt. J., 229, 463-466).-After decolorising thewine, which, when examined in tubes 220 mm. long with Wild'slarge polaristrobometer, shows a slight dextro-rotation of 0.4 to0.6" (1" Wild = 4,6043" Soleil = 2.89005" Ventzke-Soleil), 250 to3.50 C.C. are concentrated until the salts begin to crystallise out.The concentrated solution is, after the addition of a sufficient quan-tity of pure aqimal charcoal, diluted to 50 c.c., and filtered.Thefiltrate, generally of a, faint yellow colour, shows with most winesa slight dextro-rotation in tubes 220 mm. long, which varies withpure Rhine, Haardt, and Markgrafler-wines, from the years 1874to 1876 between 0.5 and 2". The 50 C.C. are next evaporated to RAdulteration of Wine.scope. w. c. wANALYTICAL CHEI1IISTRT. 83syrupy mass on the water-bath, the residue being treated graduallyand with careful stirring with a quantity of 90 per cent. alcohol,large enough to throw down all precipitable matter. After havingallowed the mixture to stand for 6 to 8 hours, the alcohol is eitherpoured off or filtered off, and the residue extracted with cold water.The solution is decolorised with animal charcoal and filtered. In allnatural wines the dextro-rotatory substance is chiefly in this alcoholicprecipitate. The alcoholic filtrate is evaporated h one-fourth of thevolume originally added, and the cold solution treated gradually withfour to six times its volume of ether, shaking the mixture the wholetime.After standing, a more or less thick aqueous solution separatesunder the ether, which in wines containing potato-sugar contains thenon-fermentable substances of these preparations, soluble in alcohol(amylin), and consequently shows a strong dextro-rotation. Afterremoving the ether, the aqueous solution is diluted with water, warmedon the water-bath, to expel all ether, decolorised with animal charcoal,and the filtrate diluted according to the size of the observation-tube tothe necessary volume.With pure natural wines of medium growths,which no longer contain unfermented sugar, the dextro-rotation ofthis aqueous solution of the ether precipitation from 250 to 350 C.C. ofwine is, after discoloration and dilution to 30 C.C. either nil, as inmost cases, or a t the most, 0.2" to 0.5". The tables given in theoriginal paper show tjhat all wines having a rotation of 0.1" t o 0.3" tothe right, may be regarded as perfectly pure. If, however, the dextro-rotation is 0.5" to O*Ci", it is more satisfactory to apply the abovc-described method. D. B.Alizarin Colouring Matters, and Green Aniline Colours.By H.W. VOGEL (Deut. C'henz. Ges. Bes., 11, l371-l374).-Alizarir~-bZue.-This body dissolves in water on addition of ammonia witchindigo-blue colour, and shows a two-sided absorption of the spectrum,which appeared considerably stronger in the red than in the dark blue,and no bands could be recognised. Supersaturated with nitric acid,the solution becomes brick-red, and exhibits an absorption similar tothat of red litmus tincture with a dark shadow in the green. Amy1alcohol extracts the colouring matter quickly from the acid solutio~i,but only with difficulty from the alkaline solution. Alcohol dissolvcsthe colouring matter in the completely neutral condit'ion, with violetcolour. Treated with ammonia, the solution becomes blue, like cupricsulphate solution, and exhibits in the concentrated state a continuousabsorption of the red end of the spectrum, and on diluting with alcohol,a highly characteristic spectrum reaction for alizarin-blue is developed.This consists of three bauds, the weakest of which is on D, thesecond between d and C (daylight), and the third on the extreme limitof the red, and is perceptible only with the strongest lamp-light.Potash acts differently on the alcoholic alizarin-blue solution.Itbecomes of a beautiful green, and then absorbs on both sides, moststronglyat the red end of the spectrum, but without bands. Theaqueous solution gives the same reaction. As regards detecting thecolouring matter, it is best to warm the coloured fabric with dilute9 S4 ABSTRACTS OF CHELWCAL PAPERS.hydrochloric acid, extract the colouring matter with amyl alcohol,and treat this with alcohol and ammonia.AZiznrin-orarzge (nitro-alizarin) in alcoholic solution shows a strongextinction of the blue, and a weaker one of the green.With certaintlegrees of concentration bwo very indistinct bands are recognised inthe green. With ammonia the solution becomes coloured reddish, andthen shows a stronger absorption of the green. With nitric acid itbecomes bright yellow, and gims a one-sided absorption of the blue.Potassium hydroxide colours the alcoholic solution a beautiful rosecolour, and gives then a continuous extinction of the green from F toD, in which two bands appear. Aqueous solutions of the colouringmatter with potash become yellowish-red, and show a homogeneousshade without bands in the green.The acid aqueous solution of the“ alizarin-orange ” is easily extracted with amyl alcohol, and thengives with alcohol and potash a definite spectral reaction. Fromcoloured textures, it is extracted just as “ alizarin-blue ’’ is.Both “ iodine-green ” and metliylrosaniline picrate show in dilutealcoholic solution an absorption-band between d and C. ‘‘ Iodine-green ” shows further a weak band on the D line, which disappears ondilution. The concentrated alcoholic solutions of both colours dilutedwith water turn their absorption-band somewhat towards the green(difference from “aldehyde ” and “ malachite-green ”). A drop ofnitric acid added to the alcoholic solution of the “iodine-green” effectsno alteration in the bands (difference from “ aldehyde-green ”). Thegreen picrate is tlirned bluer with nitric acid, and the bands widentowards the green. A drop of ammonia colours “iodine-green ”solution violet, with formation of a band on the D line. The greenpicrate does not show this reaction ; it becomes yellowish. By additionof ammonia to the nitric acid solutions of the colouring matter, theoriginal colour and the spectral bands gradually return.Jfnlnchite-green, in its optical behaviour, exhibits striking resemblanceto “ aldehyde-green,” but diff’ers from it in its chemical properties.The former dissolves much more easily in alcohol, and the solutionappears bluer than that of “ aldehyde-green.” Dissolved in alcoholand suitably diluted, both give exactly the same spectrum. I n highlydilute solutions, one band appears on the d line, widening itself in con-centrated solution, and besides, a continuous absorption of the blue.The only difference between the two colours is that the “ aldehyde-green” weakens the red right and left from the absorption-bandsomewhat more strongly than “ malachite-green ; ” with the latter, theband appears, on the other hand, considerably darker. Although sosimilar in optical properties, the two colours differ decidedly in theirbehariour with acids. A drop of hydrochloric acid or nitric acidadded to the alcoholic “ aldehyde-green ” effects no apparent, alterationof colour ; on the contrary, in the nitric acid solution a striking altera-tion of position of the absoibption-band to the right is remarked, whilstthe band of the “ malachite-green ’’ does not suffer the least alteration.With ammonia, “ malachite-green ” is almost immediately decolorised.“ Aldehyde-green,” on the contrary, becomes gradually blue, with ap-pearance of three faint bands, of which the last lies in the extremered, and can be recognised only by the aid of a very bright lampTECHNICAL CHEMISTRY. S .'ilight; the second is between d and C, and the third and weakest onD. The colours are easily extracted froin the textures with alcohol,and can be determined in the solution by the prescribed reactions. w. s