ANALYTICAL CEERZISTRP. 85 A n a 1 y ti c a 1 C h e m i s t r y. Grinding Mill for Minerals. By K. ZULKOWSKY (Bey., 20, 2664--2669).-A description of a mill in which minerals may be readily reduced to fine powder. The grinding surfaces are of agate, and the pestle is so arranged that it can be rotated by a water-motor against the lower surface with a pressure capable of being varied at will. The material, already reduced to the coarseness of sand, is intro- duced into the mill through a sector cut in the pestle. w. P. w. Determination of Sulphur in Pyrites. By J. W. WESTMORELAND (J. SOC. Chem. Ind., 6,84-87).-1t is shown that the results obtained by Lunge’s “ old process ” (precipitation of the sulphur from ferric solutions), agree closely with those given by bhe new process (pre- cipitation after separation of the ferric oxide by ammonia), which is therefore a needless elaboration.The new method is also liable to ’losses caused by an extra filtration and washing, aiid by sulphur retained in the ferric oxide, whilst sulphur is liable to be introducrd by the ammonia and hydrochloric acid employed. The results obtained by Lunge’s processes express the total percentage of sulphur in Spanish pyrites; i t is, however, necessary to, use only a moderate excess of barium chloride for precipitation, great care being taken in the use of hydrochloric acid when washing this precipitate. D. B. Es.timation of Sulphur in Pyrites. By G. LUNGE (J. SOC. Chem. Ind., 6, Sti).---The author criticises Welch’s process (Abstr., 1887, 180) for assaying iron pjrites for sulphur available for sulphuric acid manufacture, and shows that the experiments having been made with Kjeldahl’s Method of Estimating Nitrogen. By F.W. D A F E t w ( L n d w . Versucks. Stat., 34, 311-353).-1n this article, are detailed impure lead sulphide are not conclusive. I>. 13.86 ABSTRACTS OF CHEMICAL PAPERS. in full the resnlts of experiments made for the purpose of testing the value of Kjeldahl’s process for estimating organic nihrogen, and of an examination of the various‘ modifications of this process, as recom- mended by Kreusler and others. Estirnutiom hy the Original Process.-Certain nitrogenous compounds only seem to yield their nitrogen in the arnmoniacal forms, the result being that the process is inaccurate with regard to others; of the latter class, anilines and hydrazines are special examples, but some compounds, contrary to expectation, yield their nitrogen as ammonia more readily than others ; as for instance, it was expected that hydr- azines would yield ammonia more completely and quickly than nitro- compounds, but the contrary is the cme.The Action of the Sulphuric Acid.-To aid the solution of this question, Kreusler’s modification, where phosphoric anhydride is added to the sulphuric acid, was employed; sugar was also added. The explanation which is given is, that, the sulphuric acid removes from the substance the elements of water and of ammonia, and the sulphurous anhydride formed in the reaction reduces the nitrogenous cornpound ; the addition of organic matter (sugar) to the nitrogenous compound slackens the formation of ammonia when the compound is not volatilised by the acid; consequently to obtain quantitative results, the sulphuric acid must not volatilise the compound, nor completely decompose it, for the analysis of some substances by this method free nitrogen accompanies the ammonia. The Action of Permanganate.--The presence of the permangannte when used in company with the mixture of acids, causes a destruction of the organic matter present, the nitrogen being so separated that nearly the whole of i t is transformed into ammonia; as a rule this modification of Kjeldahl’s process may be employed for all quantitative analyses, but i t is necessary that the mixture shall be thoroughly and sufficiently heated.The Addition of Metallic Salts.-This modification of Wilfarth’s renders the original procegs more rapid, although the time required for the analysis is shortened very considerably by the addition of mercury, it is a t the cost of accuracy ; it should only be introdnced in those cases where very stable compounds are under examination, or also when the compounds readily give up their nitrogen as ammonia.From careful examination, it appears that, the discrepancies which exist between the results obtained by Kjeldahl’s original method, Wilfarth’s and Ulsch’s (addition of platinum chloride), are due to loss of nitrogen at9 nitrogen, and not; to an insufficiency of heating, when the compound is only slightly stable. The author considers t h a t Wilfarth’s explana- tion of the reaction which occurs when metallic salts are present, is satisfactory, but he also adds that when those compounds which do not resist the action of sulphuric acid well, or which are readily oxidised, are dealt with, the addition of the metallic salt causing violent oxidation, ammonia may be in part replaced by nitrogen; increasing the quantity of platinum, addition of oxygen and mixing with organic substances may also result in loss, even wben the compound is not easily decomposed.Mercury 8hould be alwnjs employed when very stable compounds are to be analysed; aminesANALYTICAL CHEMISTRY. 87 and alkaloids resist oxidation, but TJlsch’s process must not be used because of its uncertainty, except in special cases, for example, with potassium nitrate. General AppZicatinn,.--Nitrogenous compounds may be divided into two clasves as regards the applicability to them of Kjeldahl’s process of analysis.In the first are placed those which can be analysed without any previous treatment, for example, all amides and ammonium bases, pyrroline and quinoline compounds, alkaloyds, bitter substances, albuminoyds and their allies, and perhaps the indole group ; whilst to the second class belong all nitro-. nitroso-, azo-, diazo-, hydrazo-, and azoamido-compounds, nitrates and nitrites, the hydrazines, and possibly the cyano-compounds. Two methods may be employed for the previous treatment of this second class : addition of an organic substance, or reduction with zincadust, and even the tlwo combined, but the choice of which is to be used must rest with the analyst.This uncertainty will for the present preclude Rjeldahl’s process, or its improvements, from supplanting Dumas’s older and exact method. For the estimation of nitro-compounds, it is recommended to dissolve the substance in 10 C.C. of alcohol (or if it is very stable, directly in sulphuric acid) decompose by zinc-dust, add 10 C.C. of acid, and warm until all alcohol is got. rid of; when this is accomplished, add 10 C.C. of the acid mixture together with mercury, and then proceed as with an ordinary compound. When distilling with sodium hy- droxide, special care must be taken to avoid shaking the flask ; it is therefore advisable to apply heat by mean8 of a sand-bath; in the same manner nitroso- and azo-compounds may be readily analysed.Hydraao-compounds must first be converted into azo-compounds, before exposing them to the action of the sulphuric acid. The author, for example, heats the sulphate of phenylhydrazine first with excess of cane-sugar in presence of sodium acetate for some hours on a water- bath ; after drying the resulting mass, the acid may be added, Most cyano-compounds, as far as the author is aware, can be analysed by this process, but some may exist which will not bear the method. E. W. P. Notes on Nesslerising. By J. M. MILNE (J. XOC, Chern. Ind., 6, 33).-The author recommends Hehner’s method in which the new- lerising is conducted in graduated cylinders having a somewhat broad foot, a glass tap being fused into their sides near the bottom, so that the solution, either standard or water distillate, may be run out until the two tints correspond.This method, a description of which was given in Chem. News, 33, 185, is very simple and readily carried out. As nesslerising cannot be done in gaslight, the author proposes to imitate the process with two shades of indigo solution. D. B. Estimation of Ammonia in Soils by the Knop-Wolf Method. By A. BAUMANN (Lanndw. Versuchs-Stat., 34, 259--276).-A reply to Knop (ibid., 33, 438). Moisture and Free Acid in Superphosphates and similar Fertilisem. By J. RUFFLE (J. SOC. Chen~ Ik.i., 6, 327-333).--It is88 ABSTRACTS OF CHEXICAL PAPERS, shown tbat the soluble phosphoric acid existing in superphosphates is not entirely present as monocalcium phosphate, and that exposure to 100" drives 08 more than the true moisture, that is, the adhering uncombined water. It is recommended to determine the moisture in the following manner:-Weigh out 2 to 5 grams of the superpbos- phate in its natural state on a double watch-glass, place under an air-pump over dry calcium chloride, exhaust, then leave f o r 18 to 24 hours and weigh.The author shows that the acidity of ordinary superphosphates and ammoniated superphosphates is due to phos- phoric acid, and not to sulphnric acid. In ammoniated superphou- phates, monocalcium phosphate is substantially absent, the free acid being phosphoric acid. I). B. Detection of Small Amounts of Carbonic Anhydride and other Gases. By 0. ROSSLER (Bey., 20, 2629-2631).-A small test-tube is drawn out at the lower end to a capillary; this is bent upwards, and cut off a t a distance o€ 1 cm.from the bend. A capil- lary funnel is then made of such a size that the upper end fits the test-tube, the lower end being a t n distance of 1.5 to 2 cm. from the bottom. The substance to be tested for carbonic anhydride is put into the outer tube, the capillary funnel containing baryta-water fitted, and the lower end of the apparatus then dipped into hydro- chloric acid. With 0.0005 gram of sodium carbonate a very distinct turbidity, with 040005 gram a distinct turbidity is produced in the drop of baryta-water a t the end of the capillary. It is possible to detect 0.02 milligram of carbonic anhydride. Sulphuric and nitric acids, hydrogen sulphide, ammonia, &c., can also be detected by means of the apparatus, using iodide of starch, ferrous chloride, lea,d acetate, and copper sulphate respectively.A sketch of the apparatus is given. N. H. M. Absorption of Carbonic Oxide by Cuprous Chloride. By H. DREHSCHMIDT (Rer., 20,2752-2755).-Hempel has recently shown that in certain cases when cuprous chloride is used as an absorbent of carbonic oxide in gas analysis, there is an increase instead of a decrease of volume. This result is explained on the supposition that the ethylene contained in the absorption-liquid is driven out by the absorbed carbonic oxide. It is here shown that this explanation is not sufficiently valid, as similar results were obtained with mixtures of carbonic oxide, with hydrogen, or nitrogen only. Experiments are described in which a given volume of hydrogen was added to the volume OE gas obtained after some of the carbonic oxide had been absorbed ; on completing the absorption, a fresh quantity of carbonic oxide was added, and the experiment repeated.I n all cases, whether an ammoniacal or hydro- chloric acid solution of cuprous chloride was used, an increase of volume of the hydrogen was observed, the increment being greater in the case of the acid solution. If is advisable, therefore, when carbonic oxide is present in small qnantities, to use a fresh ammoniacal solution, or to burn with air by means of palladium asbestos. If the amount of carbonic oxide is large, a portion of the gas is unabsorbed, and must mbsequently be determined by the above methods. V. H. V.ANALYTICAL CHEMISTRY. a9 Estimation of Potassium by Reduction of the Platinochlo- ride with Sodium Formate.By WOUSSEN (Ann. Agronwm., 13, 431--432).-The author has made Corenwinder's process workable by securing tbe agglutination of the reduced platinum. The modified process is conducted ils follows :-SO much of the substance should be taken as will yield 0.750 t o 1 gram of reduced platinum from the potassium platinochloride. This is precipitated with 18 C.C. of a solution of platinum tetrachloride, containing 200 grams per litre, and a slight excess of nit,ric acid ; 8 to 10 C.C. of hydrochloric acid is added, and the solution evaporated to dryness on the water-bath, then taken up with a mixture of nine-tenths alcohol of 96", and one-tenth ether, filtered, and washed with the same mixture.The mixture of potassium platinochloride and salts remaining on the filter is treated with a jet of boiling water, and the hot solution of the platinochloride thus formed added in portions to a boiling solution of 2 to 2.5 grams of sodium formate in 10 C.C. of water. The boiling is continued for 15 to 20 minutes, and then 8 C.C. of hydrochloric acid is added, and the boiling continued with constant agitation. After this addition the reduced platinum soon agglutinates, and leaves the solution clear; the metal is cotlected, washed with boiling water, dried, and Estimation of Potash in Commercial Manures. By D. LINDO (Chem. News, 56, 163--165).-Gladding has proposed the fol- lowing method for this purpose :-Boil 10 grams of the manure for 10 minutes with YO0 C.C.of water, when cool precipitate b~ means of a slight excess of ammonia, make up to 500 c.c., and filter. Evapo- rate 5~ C.C. of the filtrate nearly to dryness, add 1 C.C. of dilute sul- phuric acid (1 : l), continue the evaporation to dryness, and ignite. Dissolve the residue in hot water and a few drops of hydrochloric acid, add 5 C.C. of a 2 per cent. solution of sodium chloride and an excess of platinum chloride solution and wash the precipitate succesdvely with alcohol, solution of ammonium chloride (saturated with potassium platinochloride), and filially again with alcohol, dry, &c. The author has made numerous experiments with this method, and finds it simple, more expeditious, and seemingly suscept*ible of greater accuracy than the methods usually employed.D. A. L. Estimation of Sodium Hydroxide in Soda-ash. By R. WIL- LIAMS ( J . rs'oc. Chenz. h i d . , 6, 346).-The following method is found to give accurate results :-A weighed quantity of soda-ash is agitated with strong alcohol in a stoppered flask and left over night; the un- dissolved carbonat,e is filtered off and washed with strong alcohol until a drop gives no alka!ine reaction ; the filtrate and washings are then titrated with normal acid. D. B. weighed. J. M. El. 31. Estimation of the Relative Amounts of Sodium Hydroxide and Carbonate in Commercial Soda-ash. By P. HART ( J . SOC. Chem. Ind., 6, 347).-The sample under examination is titrated wit,h standard acid, using phenolphthalejin as indicator. As soon as the colour disappears, the whole of the hydroxide and one half of the soda90 ABSTRACTS OF CHEMICAL PAPERS.existing as carbonate has been neutralised, the number of C.C. being noted. To the same solution (in which the soda now exists as sodium hydrogen carbonate) a little methyl-orange is added, ahd the addition of acid from the same burette continued to neutral reaction. By doubling the difference between the two titrations and deducting the number from the number of C.C. consumed, the quantity of hydroxide in the original sample is obtained. D. B. Analysis of Alum Cakes. By R. WrLLims (Chem. Nezos, 56, 194-195) .-The author has adopted the following methods :-For alumina : neutralise the solution with sodium carbonate, add a large excess of sodium hyposulphite, boil for some time, wash, dry, ignite, and weigh the precipitate.For free sulphdric acid : digest all night with strong alcohol, and titrate the alcoholic extract directly with decinormal soda, using phenolphthale’in as ihdicator, Evaporating off the alcohol gives rise to loss, low results ate likewise obtained if the digestion is not continued for a sufficient time. In another method, a, weighed quantity of quinine, morphine, or strychnine is treated with a known quantity of alum solution, and the alkalo’id reweighed after the treatment, the loss representing the alkalojid dissolved by the free acid. Comparative results were obtained as follows :- Alcohol. Strychnine. Quinine. Morphine. Free H2SOa per cent.. . 0.41 0‘54 0.50 0.51 The alkalo’id results are all higher than the alcohol, probably on account of some alkaloid being dissolved by the alum solution and reckoned as sulphate.Determination of Minute Quantities of Iron, wi€h Special Reference to Alum and Aluminium Sulphate. By R. R. TAT- LOCK (J. Soa. Chew. Ind., 6, 276--279).-As a standard, a solution of iron-alum is used, of which 1 C.C. equals 0.001 gram iron, Place 1 gram of the finely powdered sample in an ordinary atoppered sample-tube of about 30 C.C. capacity, and having three marks at 7.5, 10, and 20 C.C. respectively. Add 1 C.C. of standard sulphuric acid, and make up to the lowest mark with water. When +he alum under examination is dissolved, add 0.2 gram of ammoninm thicjcya- nate and make up to 10 c,c. with water. Place 1 cx. of the standard iron solution in a 100-c,c. flask, and make up to the latter volume with water.Now place 1 C.C. of this diluted solution in a stoppered sample-tube, add 1 C.C. of standard acid, make up to the lowest mark with water, add 0.2 gram of the thiocyanate, and make up to the 10 C.C. with water. Then fill up both tubes to the 20 c.c, mark with ether, and agitate them thoroughly, As soon as the contents settle, compare the tints, and if unequal make one or more further trials with greater or less quantities of standard iron solution until the two tints correspond. D. B. By J. H. SMITH (J. SOC. Chem. Ind., 6, 98-111 and 260--271).-When potaa- sium permanganate is used as an oxidising agent in organic research, D. A. L. Detection and Estimation of Organic Substances.ANALPTICAL CHEMISTRY. 91 impure products are obtained, and in varying proportions depending on the amount of reagent employed, temperature, and other conditions.It has therefore only been generally employed as a qualitative reagent. From a study of the behavionr of solutions of various organic sub- stances in presence of a large excess of potassium permanganate under varying standard conditions, it occurred to the author tlhat by employ- ing an excess of the reagent, definite and sjmple compounds would be obtained whose composition in each case might be determined quali- tatively by ordinary analysis, and quantitatively by an estimation of the oxygen absorbed in the reaction. The determinations which the author had in view were the: following :-Oxygen yielded by excess of manganese dioxide in acid, alkaline and neutral solutions respectively ; oxygen yielded by excess of permanganate in such soliitions.The latter would include the former, the difference would represent oxygen yielded by permanganate in reduction to manganese dioxide only, and would necessarily correspond with more stable compounds than those represented by the reduction of manganese dioxide. The author further anticipated successive oxidations, more especially of a neutral one succeeded by an alkaline and acid one respectively, and an alkaline oxidation followed by one in acid solution. It was found, however, that on oxidising an organic or other oxidisable solution by tt large excess of permanganate in acid solution, the results generally came out much too high, even for perfect oxida- tion, which indicated a loss of oxygen due to the presence of manga- nese dioxide.In order to prevent or diminish f h e loss, a ferric salt was added to the permanganate solution, the iron acting as an accelerator in the preseiice of much permanganate and little manganese dioxide, and a retarder when the conditioiis were reversed. The ferric salt is really an accelerator, but it has the power of neutralising the action of the manganese dioxide after a certain excess has been formed. The accelerating action of iron in presence of much per- mangmate may be checked by the addition of sodium phosphate to the solution. The author has based a quantitative method of estimating organic: products on the results obtained from this investigation, The method, which is described in detail in the original, is applicable to the estima- tion of commercial organic substances, the determination of t8he organic matter in potable waters and in the waste liquors from works employing organic products, whilst for the estimation of alcoholic solutions when largely diluted, it is more rapid than the sp.gr. method. I n the second part of the paper, the author treats cf the oxidation of organic substances by means of manganese dioxide in acid soll;tion, as well as of oxidations by permanganate in neutral and alkaline solutions, and of analytical methods derived therefrom. The Stalagmometer : a New Method for the Determination of Fuse1 Oil in Spirituous Liquors. By J. TRAUBE (Rer., 20, 2644--2655).-The author previously described (Abstr., 1886, 743) a method for determining fuse1 oil in brandy by observing the height of the solution in a capillary tube. In the present paper an apparatus, D.B.92 ABSTRACTS OF CHEMICAL PAPERS. called n “stalagmometer,” is described by means of which the percentage of fusel oil is determined by counting the drops contained in a kiiown volume of liquid. As in the older method, the brandy is first diluted so as to be about 20 per cent. It is then put into the stalagmometer, and the number of drops from a given volume observed and com- pared with the number obtained from the same volume of pure 20 per cent. alcohol. An excess of 1% drop to 100 C.C. of liquid shows the presence of 0.1 per cent., an excess of 3.5 drops, of 0.2 per cent. of fusel oil. 0.05 per cent. of fusel oil can be determined readily and with certainty.To increase the delicacy of the method, the proportion of alcohol t o fusel oil must be diminished. This is done in the following manner:--300 C.C. of the liquid to be examined (diluted to 20 to 25 per cent.) is shaken in a funnel with 110 ta 120 grams of pure ammonium sulphate, and left until two layers are formed; the lower layer, which contains vePy little fusel oil, is drawn off and shaken with two to three drops of’ ethyl alcohol. or some crystals of ammonium sulphate. In this way the rest of the fusel oil is obtained as a separate laeyer. These upper layers are now mixed, dissolved in water, and distilled to about two-thirds. The distil- late is made u p to 110 c.c., the alcohol determined by means of A Westphal’s balance, and the number of drops contained in the volumc V by means OF the stalagmometer.The latter number is compared with that obtained from pure spirit containing a known amount of fusel oil. A sketch of the apparatus is gicen, as well 3s results obtained by means of it. These show that the method is as accurate as that previously described (Zoc. cit.), the new method having the advantage of being more easily worked. N. H. M. By J, MUTER and L. DE KOXINGH (Anulyst, 12, 191--195).-CarboZ~c Powders.- Where the phenols exist in the uncombined state, they are extracted by methylated spirit from 75 grams of the powder. Where the powder contains a lime base, a preliminary thorough trituration with a small excesR of dilute sulphuric acid is necessary. The alcoholic extract is mixed with 200 C.C.of a 5 per cent. solution of sodium hydroxide, and the mixture is then evaporated to half its bulk. At this point any tar oils and naphthalene will separate and are to be filtered off. The filtrate is further concentrated to 50 C.C. and trans- ferred to a graduated tube. This, which is known as Muter’s car- bolimeter, is wide in the lower portion. At 65 C.C. it is narrowed to a neck, which is graduated up to 110 C.C. in 0.35 C.C. divisions. It is stoppered, and is furnished with a long, thin, stirring rod, the volume of which must be allowed for. The solution is made up to 6.5 c.c., 25 C.C. of strong hydrochloric acid are slowly added with stirring, and then enough dry common salt t o render the phenols insoluble. The tube is plunged into water of 15.5’ and the volume of the phenols read off.Liquid Oarbolic Acid.-If this contains excess of watep, it will not give a clear solution with three volumes of benzene. The amount of Assay of Commercial Carbolic Compounds.ANALYTICAL CHEXISTRY. 93 water is ascertained by shaking 20 C.C. of the sample with 80 C.C. of a saturated solution of sodium chloride, and observing the diminntion in volume. Tar oils are estimated by shaking 20 C.C. with 80 C.C. of mda solution (5 per cent.), and a small quantity of benzene (10 C.C. for dark specimens, less for pale ones). The increase in the volume of the benzene gives the amount of t a r oils. The remainder i, taken as phenol and cresols. M. J. s. Acidimetry with Red Wines. By TONY-GARCIN (Comyt. read., 105, 577).-When red wine, prepared in the ordinary way and not more than a year old is mixed with sodiam hydroxide solution, the colour changes to carmine, which becomes deeper and duller and passes into violet-black, which afterwards becomes black, without any tinge af violet, and then changes to green, with formation of a dark, flocculent precipitate.The point a t which the colour is brownish- black, without any tinge of violet or green, is the point of exact neutralisation. C . H. €3. Dairy Products. (Bull. U, 8. Agrz‘c. Depart., No. 13, 1-128).- Butter and its Substitutes.-A series of micro-photographs is given, showing the appearance presented by butter, &c., when examined by polarised light. The black cross described by Hehner and Angel1 is seen in all the specimens of butter prepared by boiling and slow cooling, and is almost uniformly absent from the crystals obtained from the other fats, nevertheless it is shown by some specimens of birtterine and oleomargarine from Armour and Co., Chicago, as well as in a slide prepared from beef suet “oleo oil,” by dissolving in hot alcohol, and cooling slowly, thus confirming the opinion that it is not to be trusted as a characteristic of genuine butter.The following method for determining the melting point of fats is described :-Thin discs are obtained by dropping the melted fat on to a piece of ice. One of these is placed in a test-tube, t h e lower part of which contains boiled water, and the upper part strong alcohol. The disc floats between the two liquids. The tube is then warmed in a water-bath, whilst the temperature of the contents is taken by a thermometer with small bulb, situated just above and close to the disc, and kept in motion like a revolving pendulum.The ternpera- ture a t which the disc contracts to a sphere is taken a s the melting point. It is necessary to examine the discs when freshly made, as they show a higher melting point if kept for 24 hours. When the water-alcohol tube is warmed before dropping in the disc, the con- traction takes place some 6” lower than when the former method is followed. Daven- port saponifies 5 grams of the butter with only 10 C.C. of alcoholic potash (cont,aining 2 grams of KHO), operating in a flask from wThich the alcohol vapour is aspirated by a water-pump. Saponification and evaporation to dryness are complete in 15 minutes, and from the statement that genuine butters treated thus require on an average 28.8 C.C.of - alkali, there would appear to be no loss of ethyl buty- Various modifications of Reichert’s process are described. N l d94 ABSTRACTS OF CHEMICAL PAPERS. rat'e (compare Allen, Abstr., 1857, 1145). Crampton substitutes phosphoric for sulphuric acid in the distillation, but finds that with care the two give identical results. Scheffer's test for foreign fats is based on the solvent action of a mixture of amyl alcohol (40 vols.) and ether of sp, gr. .On715 (60 vols.). 1 gram of butter dissolves in 3 C.C. of this mixture at 28" ; 1 gram of lard requires 16 C.C. ; 1 gram of stearin 350 C.C. The following order of value is assigned to the various modes of examining butters for adulteration :-( 1.) Determination of volatile acids.(2.) Determination of specific gravity. (3.) Determination of saponification equivalent (Koettstorfer). (4.) Determination of the insoluble acids (Hehner, Muter, Blyth, &c.X ( 5 . ) Det,errnination of the melting point. A complete bibliography of butter analysis (up to 1882) is given by Caldwell (Seeond Ann. Rep. N . Y. S. E d . of B e a l t h , ,544-547), and i n Sell's Kunstbutter (Arbeit a. d . R a i s e d . Geswndheitsumte), MiEk.-For the determination of water, Babcock employs asbestos to absorb the milk before drying; this is much to be preferred to any powder, By placing the asbestos in a, tube between plugs of cotton- wool, and drawing air through the tube wbile it is heated a t loo", the desiccation is complete in two hours. The tube can then be transferred to the f a t extractor, Of methods for the determination of the fat, the preference is given t o that of Adams (Abstr., 1886, 583), but instead of soaking up the milk with one end of the roll of paper, the plan has been adopted of holding the unrolled strip in a horizontal position, and running the 5 C.C.of milk from a pipette along the middle. The strip is then hung up in a hot chamber, and in two or three minutes is dry and ready for rolling up. In Soxhlet's araometric method (Abstr., 1881, 656) great difficulty was encountered in ensuring the separation of the ethereal fat soln- tion, and any long delay in the separation was found to affect the final results. By placing the bottles containing the mixture in a centrifugal machine revolving about 300 times per minute, the time required for separation was reduced to a few minutes, only six samples out of 150 requiring more than quarter of an hour.The fat solution thus separated had, however, a lower specific gravity than that obtained by simple subsidence, so that the percentage of fat as given in Soxhlet's table had to he increased by 0*1:3, to bring it into agreement with the results of the older method. Cronander also separates the fat by shaking the milk with potash and ether, hut evaporates the ether after i t has risen to the surface of the milk, and measures the fat by forcing it in a melted state into a graduated tube. Pleischman and Morgen calculate the fat by the formula- 100s - 100 S-' f = 0.833 - 2.22 where f = percentage of fat, t = percentage of total solids, S = specific gravity of the milk a t 15".Morse and Piggot add 10 C.O. of milk to 20 grams of dehydrated copper sulphate. The fat The milk becomes dry in a few moments.ANALYTICAL CHEMISTRY. 95 i a then extracted by light petroleum, and its amount determined (after evaporation) by saponification. It is a graduated glass cylinder, containing in its lower part a amalley cylinder of white glass with black lines on it. 4 C.C. of milk are put jn the cylinder, and water is added until the black lines become visible. The reading of the total rolume gives at once the per- centage of fat. For the determination of the free acid in konmiss, it bright filtrate was obtained by adding to the koumiss an equal volume of alcohol Of lactoscoyes, Feser’s is said to be the most convenient.before filtering. B!. J. s. Extraction of Fats by Soxhlet’s Apparatus. By J. M. MILNE (J, SOC. C‘hem, Ind., 6, 34).-1n using the apparatus for milks, the author procwds as follows :-About 10 C.C. of the milk is weighed into a tared porcelain basin, and the milk evaporated with frequent stirring in arder to render it granular, until on being cooled the residue is semi-solid. The residue is then transferred to a paper cup and placed into the Soxhlet tube, and the fat extracted with ether in the usual way, The author having worked with Adams’ paper coils for drying np milk for fat extractions, confirms the fact pointed out by the committee of the Society of Public Analysts, that from 0.3 to 0.5 per cent.more fat is extracted by the coil method. Examination of Wines and Oils. Ry P. SPICA (Gszzetta, 17, 304--312).-The author at the outset; makes the oft-repeated com- plaint that the conditions, such as the variation of concentration, or even the nature of the acids used, required for the successful applica- tion of test-reactions, are not defined wit.h sufficient exactness in original papers. Various processes have been proposed to recognise the colouring matters, whether natmal or artificial, of wines ; but preference is given by the author to the methods proposed by Caze- neuve (AbRtr., 1886, 397), Arata (Gazzetta, 17, 44), Blarez and Deniges (Abstr., 1886, 1084), and Girard and Gautier.In the last- named process the substitution of tablets of Mugnesisc aZba for those of plaster of Paris is suggested ; hhese are immersed in egg albumin for a shart time and dried. A drop of the wine to be examined is let fall on such a prepared tablet, and the colour of the stain produced is observed. The natural colouring matters of wine give a yellowish- brown, those containing rosaniline or ‘‘ vinoline ” a reddish-jellow, those with indigo an azure-green, with orchil a violet red, and those with amaranth a greyish-violet stain. Another method suggested con- sists in shaking up the wine with barytn-water and amyl alcohol, when the latter extracts the colouring matter from the wine. It appears that certain preparations containing coal-tar colouring mat- ters, called “ vinoline,” are sold by druggists in Padua. An examina- tion of such a, preparation, called “maroon vinoline,” was found to consist of about 40 per cent.of mineral matter, in which arsenic was present in considerable quantities. As regards the method of examination of oils proposed by Maumen6, which is founded on the rise of temperature when the D. B.96 ABSTRACTS OF CHEMICAL PAPERS. sample is mixed with concentrated sulphuric acid, it appears that a confusion has arisen between grams and cnbic centimetres. Con- cordant results are obtained with mixtures of 50 grams or 55 C.C. of oil with 10 C.C. of acid. Bechi has proposed a method for the recopnit'ion of cotton-seed oil in 01iv.e oil. which consists in adding to the oil an alcoholic-ethereal solution of silver nitrate in presence of an amyl alcohol solution of petroleum ; it is here shown that this method gives fallacious results. A method of the greatest practical value is that proposed by Hubl, which has given satisfactory results in the hands of Moore, Allen, Oglialoro, and other observers. Gravimetric Estimation of Tannins.By H. R. PROCTER (J'. Xoc. Chem. Ind., 6,94--96).-The process described by the author is a combination of the methods published by Muntz and Simand, and depends on the fact that in filtration through a column of dry hide powder the upper layers absorb most of the tannin, a very com- plete and rapid separation being obtained from the large surface exposed. The author utilises the lamp chimneys employed in the common round-wicked German petroleum lamps, which are con- tracted just above the base of the flame and are cylindrical for the re- mainder of their length.A perforated disc of cork is made slightly cup-shaped on its two faces. A piece of linen is then stretched over it, and i t is pressed down the chimney until i t rests on the contracted neck. Five grams of hide powder is weighed into the tube, and when shaken down will occupy a space of about 50 C.C. The tube is now cut off, allowing only length for the insertion of a cork, which may press slightly on the powder, as it contracts in volume when wet. This cork is perforated and hollowed like the first, and after being covered with linen is pressed into the tube. A short piece of quill tubing passes through the cork, and is fitted by a second cork into a flask.The filtering tube is inverted, broad end downwards, into a beaker of 100 C.C. capacity, which is filled with the liquid to be filtered until it rises into the hide- powder. The tube is left in this position for one or two hours, after which it is reversed, and the enlarged end filled with the solution, when the filtration will be found to proceed evenly and steadily. The filtrates thus obtained are per- fectly free from tannin, and tested by,the Lowenthal method show a lower result for " aon-tannin " than those by any other method of ab- sorption. The method is, however, inapplicable in the presence of gallic acid, t,he latter being freely absorbed by hide powder. The author hopes to overcome the difficulty either by some method of V.H. V. removing the gallic acid or of preventing its absorption by the hide. D. B.Jaum . Chem .Sue. Feb. 1888. BALL No 3 . Harrison & Suns. Lith. S. Murtins Lane. W.C.ANALYTICAL CEERZISTRP. 85A n a 1 y ti c a 1 C h e m i s t r y.Grinding Mill for Minerals. By K. ZULKOWSKY (Bey., 20,2664--2669).-A description of a mill in which minerals may bereadily reduced to fine powder. The grinding surfaces are of agate,and the pestle is so arranged that it can be rotated by a water-motoragainst the lower surface with a pressure capable of being varied atwill. The material, already reduced to the coarseness of sand, is intro-duced into the mill through a sector cut in the pestle. w. P. w.Determination of Sulphur in Pyrites. By J. W. WESTMORELAND(J. SOC.Chem. Ind., 6,84-87).-1t is shown that the results obtainedby Lunge’s “ old process ” (precipitation of the sulphur from ferricsolutions), agree closely with those given by bhe new process (pre-cipitation after separation of the ferric oxide by ammonia), which istherefore a needless elaboration. The new method is also liable to’losses caused by an extra filtration and washing, aiid by sulphurretained in the ferric oxide, whilst sulphur is liable to be introducrdby the ammonia and hydrochloric acid employed. The results obtainedby Lunge’s processes express the total percentage of sulphur inSpanish pyrites; i t is, however, necessary to, use only a moderateexcess of barium chloride for precipitation, great care being taken inthe use of hydrochloric acid when washing this precipitate.D.B.Es.timation of Sulphur in Pyrites. By G. LUNGE (J. SOC. Chem.Ind., 6, Sti).---The author criticises Welch’s process (Abstr., 1887,180) for assaying iron pjrites for sulphur available for sulphuric acidmanufacture, and shows that the experiments having been made withKjeldahl’s Method of Estimating Nitrogen. By F. W. D A F E t w( L n d w . Versucks. Stat., 34, 311-353).-1n this article, are detailedimpure lead sulphide are not conclusive. I>. 1386 ABSTRACTS OF CHEMICAL PAPERS.in full the resnlts of experiments made for the purpose of testing thevalue of Kjeldahl’s process for estimating organic nihrogen, and of anexamination of the various‘ modifications of this process, as recom-mended by Kreusler and others.Estirnutiom hy the Original Process.-Certain nitrogenous compoundsonly seem to yield their nitrogen in the arnmoniacal forms, the resultbeing that the process is inaccurate with regard to others; of thelatter class, anilines and hydrazines are special examples, but somecompounds, contrary to expectation, yield their nitrogen as ammoniamore readily than others ; as for instance, it was expected that hydr-azines would yield ammonia more completely and quickly than nitro-compounds, but the contrary is the cme.The Action of the Sulphuric Acid.-To aid the solution of thisquestion, Kreusler’s modification, where phosphoric anhydride is addedto the sulphuric acid, was employed; sugar was also added.Theexplanation which is given is, that, the sulphuric acid removes fromthe substance the elements of water and of ammonia, and thesulphurous anhydride formed in the reaction reduces the nitrogenouscornpound ; the addition of organic matter (sugar) to the nitrogenouscompound slackens the formation of ammonia when the compoundis not volatilised by the acid; consequently to obtain quantitativeresults, the sulphuric acid must not volatilise the compound, norcompletely decompose it, for the analysis of some substances by thismethod free nitrogen accompanies the ammonia.The Action of Permanganate.--The presence of the permanganntewhen used in company with the mixture of acids, causes a destructionof the organic matter present, the nitrogen being so separated thatnearly the whole of i t is transformed into ammonia; as a rule thismodification of Kjeldahl’s process may be employed for all quantitativeanalyses, but i t is necessary that the mixture shall be thoroughly andsufficiently heated.The Addition of Metallic Salts.-This modification of Wilfarth’srenders the original procegs more rapid, although the time requiredfor the analysis is shortened very considerably by the addition ofmercury, it is a t the cost of accuracy ; it should only be introdncedin those cases where very stable compounds are under examination, oralso when the compounds readily give up their nitrogen as ammonia.From careful examination, it appears that, the discrepancies which existbetween the results obtained by Kjeldahl’s original method, Wilfarth’sand Ulsch’s (addition of platinum chloride), are due to loss of nitrogenat9 nitrogen, and not; to an insufficiency of heating, when the compoundis only slightly stable.The author considers t h a t Wilfarth’s explana-tion of the reaction which occurs when metallic salts are present, issatisfactory, but he also adds that when those compounds which donot resist the action of sulphuric acid well, or which are readilyoxidised, are dealt with, the addition of the metallic salt causingviolent oxidation, ammonia may be in part replaced by nitrogen;increasing the quantity of platinum, addition of oxygen and mixingwith organic substances may also result in loss, even wben thecompound is not easily decomposed. Mercury 8hould be alwnjsemployed when very stable compounds are to be analysed; amineANALYTICAL CHEMISTRY.87and alkaloids resist oxidation, but TJlsch’s process must not be usedbecause of its uncertainty, except in special cases, for example, withpotassium nitrate.General AppZicatinn,.--Nitrogenous compounds may be divided intotwo clasves as regards the applicability to them of Kjeldahl’s processof analysis. In the first are placed those which can be analysedwithout any previous treatment, for example, all amides and ammoniumbases, pyrroline and quinoline compounds, alkaloyds, bitter substances,albuminoyds and their allies, and perhaps the indole group ; whilst tothe second class belong all nitro-. nitroso-, azo-, diazo-, hydrazo-, andazoamido-compounds, nitrates and nitrites, the hydrazines, andpossibly the cyano-compounds.Two methods may be employed forthe previous treatment of this second class : addition of an organicsubstance, or reduction with zincadust, and even the tlwo combined,but the choice of which is to be used must rest with the analyst.This uncertainty will for the present preclude Rjeldahl’s process, orits improvements, from supplanting Dumas’s older and exact method.For the estimation of nitro-compounds, it is recommended to dissolvethe substance in 10 C.C. of alcohol (or if it is very stable, directly insulphuric acid) decompose by zinc-dust, add 10 C.C. of acid, and warmuntil all alcohol is got. rid of; when this is accomplished, add10 C.C. of the acid mixture together with mercury, and then proceedas with an ordinary compound.When distilling with sodium hy-droxide, special care must be taken to avoid shaking the flask ; it istherefore advisable to apply heat by mean8 of a sand-bath; in thesame manner nitroso- and azo-compounds may be readily analysed.Hydraao-compounds must first be converted into azo-compounds, beforeexposing them to the action of the sulphuric acid. The author, forexample, heats the sulphate of phenylhydrazine first with excess ofcane-sugar in presence of sodium acetate for some hours on a water-bath ; after drying the resulting mass, the acid may be added, Mostcyano-compounds, as far as the author is aware, can be analysed bythis process, but some may exist which will not bear the method.E.W. P.Notes on Nesslerising. By J. M. MILNE (J. XOC, Chern. Ind., 6,33).-The author recommends Hehner’s method in which the new-lerising is conducted in graduated cylinders having a somewhatbroad foot, a glass tap being fused into their sides near the bottom, sothat the solution, either standard or water distillate, may be run outuntil the two tints correspond. This method, a description of whichwas given in Chem. News, 33, 185, is very simple and readily carriedout. As nesslerising cannot be done in gaslight, the author proposesto imitate the process with two shades of indigo solution. D. B.Estimation of Ammonia in Soils by the Knop-Wolf Method.By A. BAUMANN (Lanndw. Versuchs-Stat., 34, 259--276).-A reply toKnop (ibid., 33, 438).Moisture and Free Acid in Superphosphates and similarFertilisem.By J. RUFFLE (J. SOC. Chen~ Ik.i., 6, 327-333).--It i88 ABSTRACTS OF CHEXICAL PAPERS,shown tbat the soluble phosphoric acid existing in superphosphatesis not entirely present as monocalcium phosphate, and that exposureto 100" drives 08 more than the true moisture, that is, the adheringuncombined water. It is recommended to determine the moisture inthe following manner:-Weigh out 2 to 5 grams of the superpbos-phate in its natural state on a double watch-glass, place under anair-pump over dry calcium chloride, exhaust, then leave f o r 18 to 24hours and weigh. The author shows that the acidity of ordinarysuperphosphates and ammoniated superphosphates is due to phos-phoric acid, and not to sulphnric acid.In ammoniated superphou-phates, monocalcium phosphate is substantially absent, the free acidbeing phosphoric acid. I). B.Detection of Small Amounts of Carbonic Anhydride andother Gases. By 0. ROSSLER (Bey., 20, 2629-2631).-A smalltest-tube is drawn out at the lower end to a capillary; this is bentupwards, and cut off a t a distance o€ 1 cm. from the bend. A capil-lary funnel is then made of such a size that the upper end fits thetest-tube, the lower end being a t n distance of 1.5 to 2 cm. from thebottom. The substance to be tested for carbonic anhydride is putinto the outer tube, the capillary funnel containing baryta-waterfitted, and the lower end of the apparatus then dipped into hydro-chloric acid. With 0.0005 gram of sodium carbonate a very distinctturbidity, with 040005 gram a distinct turbidity is produced in thedrop of baryta-water a t the end of the capillary.It is possible todetect 0.02 milligram of carbonic anhydride. Sulphuric and nitricacids, hydrogen sulphide, ammonia, &c., can also be detected by meansof the apparatus, using iodide of starch, ferrous chloride, lea,d acetate,and copper sulphate respectively. A sketch of the apparatus isgiven. N. H. M.Absorption of Carbonic Oxide by Cuprous Chloride. ByH. DREHSCHMIDT (Rer., 20,2752-2755).-Hempel has recently shownthat in certain cases when cuprous chloride is used as an absorbent ofcarbonic oxide in gas analysis, there is an increase instead of a decreaseof volume. This result is explained on the supposition that the ethylenecontained in the absorption-liquid is driven out by the absorbed carbonicoxide.It is here shown that this explanation is not sufficiently valid,as similar results were obtained with mixtures of carbonic oxide, withhydrogen, or nitrogen only. Experiments are described in which agiven volume of hydrogen was added to the volume OE gas obtainedafter some of the carbonic oxide had been absorbed ; on completingthe absorption, a fresh quantity of carbonic oxide was added, and theexperiment repeated. I n all cases, whether an ammoniacal or hydro-chloric acid solution of cuprous chloride was used, an increase of volumeof the hydrogen was observed, the increment being greater in the caseof the acid solution.If is advisable, therefore, when carbonic oxide ispresent in small qnantities, to use a fresh ammoniacal solution, or toburn with air by means of palladium asbestos. If the amount ofcarbonic oxide is large, a portion of the gas is unabsorbed, and mustmbsequently be determined by the above methods. V. H. VANALYTICAL CHEMISTRY. a9Estimation of Potassium by Reduction of the Platinochlo-ride with Sodium Formate. By WOUSSEN (Ann. Agronwm., 13,431--432).-The author has made Corenwinder's process workable bysecuring tbe agglutination of the reduced platinum. The modifiedprocess is conducted ils follows :-SO much of the substance shouldbe taken as will yield 0.750 t o 1 gram of reduced platinum from thepotassium platinochloride. This is precipitated with 18 C.C.of asolution of platinum tetrachloride, containing 200 grams per litre,and a slight excess of nit,ric acid ; 8 to 10 C.C. of hydrochloric acid isadded, and the solution evaporated to dryness on the water-bath, thentaken up with a mixture of nine-tenths alcohol of 96", and one-tenthether, filtered, and washed with the same mixture. The mixture ofpotassium platinochloride and salts remaining on the filter is treatedwith a jet of boiling water, and the hot solution of the platinochloridethus formed added in portions to a boiling solution of 2 to 2.5 gramsof sodium formate in 10 C.C. of water. The boiling is continued for15 to 20 minutes, and then 8 C.C. of hydrochloric acid is added, andthe boiling continued with constant agitation.After this additionthe reduced platinum soon agglutinates, and leaves the solutionclear; the metal is cotlected, washed with boiling water, dried, andEstimation of Potash in Commercial Manures. By D.LINDO (Chem. News, 56, 163--165).-Gladding has proposed the fol-lowing method for this purpose :-Boil 10 grams of the manure for10 minutes with YO0 C.C. of water, when cool precipitate b~ meansof a slight excess of ammonia, make up to 500 c.c., and filter. Evapo-rate 5~ C.C. of the filtrate nearly to dryness, add 1 C.C. of dilute sul-phuric acid (1 : l), continue the evaporation to dryness, and ignite.Dissolve the residue in hot water and a few drops of hydrochloric acid,add 5 C.C. of a 2 per cent. solution of sodium chloride and an excess ofplatinum chloride solution and wash the precipitate succesdvely withalcohol, solution of ammonium chloride (saturated with potassiumplatinochloride), and filially again with alcohol, dry, &c. The authorhas made numerous experiments with this method, and finds it simple,more expeditious, and seemingly suscept*ible of greater accuracy thanthe methods usually employed.D. A. L.Estimation of Sodium Hydroxide in Soda-ash. By R. WIL-LIAMS ( J . rs'oc. Chenz. h i d . , 6, 346).-The following method is foundto give accurate results :-A weighed quantity of soda-ash is agitatedwith strong alcohol in a stoppered flask and left over night; the un-dissolved carbonat,e is filtered off and washed with strong alcohol untila drop gives no alka!ine reaction ; the filtrate and washings are thentitrated with normal acid.D. B.weighed. J. M. El. 31.Estimation of the Relative Amounts of Sodium Hydroxideand Carbonate in Commercial Soda-ash. By P. HART ( J . SOC.Chem. Ind., 6, 347).-The sample under examination is titrated wit,hstandard acid, using phenolphthalejin as indicator. As soon as thecolour disappears, the whole of the hydroxide and one half of the sod90 ABSTRACTS OF CHEMICAL PAPERS.existing as carbonate has been neutralised, the number of C.C. beingnoted. To the same solution (in which the soda now exists as sodiumhydrogen carbonate) a little methyl-orange is added, ahd the additionof acid from the same burette continued to neutral reaction. Bydoubling the difference between the two titrations and deducting thenumber from the number of C.C.consumed, the quantity of hydroxidein the original sample is obtained. D. B.Analysis of Alum Cakes. By R. WrLLims (Chem. Nezos, 56,194-195) .-The author has adopted the following methods :-Foralumina : neutralise the solution with sodium carbonate, add a largeexcess of sodium hyposulphite, boil for some time, wash, dry, ignite,and weigh the precipitate. For free sulphdric acid : digest all nightwith strong alcohol, and titrate the alcoholic extract directly withdecinormal soda, using phenolphthale’in as ihdicator, Evaporating offthe alcohol gives rise to loss, low results ate likewise obtained if thedigestion is not continued for a sufficient time. In another method, a,weighed quantity of quinine, morphine, or strychnine is treated witha known quantity of alum solution, and the alkalo’id reweighed afterthe treatment, the loss representing the alkalojid dissolved by the freeacid.Comparative results were obtained as follows :-Alcohol. Strychnine. Quinine. Morphine.Free H2SOa per cent.. . 0.41 0‘54 0.50 0.51The alkalo’id results are all higher than the alcohol, probably onaccount of some alkaloid being dissolved by the alum solution andreckoned as sulphate.Determination of Minute Quantities of Iron, wi€h SpecialReference to Alum and Aluminium Sulphate. By R. R. TAT-LOCK (J. Soa. Chew. Ind., 6, 276--279).-As a standard, a solution ofiron-alum is used, of which 1 C.C. equals 0.001 gram iron, Place1 gram of the finely powdered sample in an ordinary atopperedsample-tube of about 30 C.C. capacity, and having three marks at7.5, 10, and 20 C.C.respectively. Add 1 C.C. of standard sulphuricacid, and make up to the lowest mark with water. When +he alumunder examination is dissolved, add 0.2 gram of ammoninm thicjcya-nate and make up to 10 c,c. with water. Place 1 cx. of the standardiron solution in a 100-c,c. flask, and make up to the latter volumewith water. Now place 1 C.C. of this diluted solution in a stopperedsample-tube, add 1 C.C. of standard acid, make up to the lowest markwith water, add 0.2 gram of the thiocyanate, and make up to the10 C.C. with water. Then fill up both tubes to the 20 c.c, mark withether, and agitate them thoroughly, As soon as the contents settle,compare the tints, and if unequal make one or more further trialswith greater or less quantities of standard iron solution until the twotints correspond.D. B.By J. H.SMITH (J. SOC. Chem. Ind., 6, 98-111 and 260--271).-When potaa-sium permanganate is used as an oxidising agent in organic research,D. A. L.Detection and Estimation of Organic SubstancesANALPTICAL CHEMISTRY. 91impure products are obtained, and in varying proportions dependingon the amount of reagent employed, temperature, and other conditions.It has therefore only been generally employed as a qualitative reagent.From a study of the behavionr of solutions of various organic sub-stances in presence of a large excess of potassium permanganate undervarying standard conditions, it occurred to the author tlhat by employ-ing an excess of the reagent, definite and sjmple compounds would beobtained whose composition in each case might be determined quali-tatively by ordinary analysis, and quantitatively by an estimation ofthe oxygen absorbed in the reaction.The determinations which theauthor had in view were the: following :-Oxygen yielded by excess ofmanganese dioxide in acid, alkaline and neutral solutions respectively ;oxygen yielded by excess of permanganate in such soliitions. Thelatter would include the former, the difference would representoxygen yielded by permanganate in reduction to manganese dioxideonly, and would necessarily correspond with more stable compoundsthan those represented by the reduction of manganese dioxide.Theauthor further anticipated successive oxidations, more especially of aneutral one succeeded by an alkaline and acid one respectively, and analkaline oxidation followed by one in acid solution.It was found, however, that on oxidising an organic or otheroxidisable solution by tt large excess of permanganate in acid solution,the results generally came out much too high, even for perfect oxida-tion, which indicated a loss of oxygen due to the presence of manga-nese dioxide. In order to prevent or diminish f h e loss, a ferric saltwas added to the permanganate solution, the iron acting as anaccelerator in the preseiice of much permanganate and little manganesedioxide, and a retarder when the conditioiis were reversed.The ferricsalt is really an accelerator, but it has the power of neutralising theaction of the manganese dioxide after a certain excess has beenformed. The accelerating action of iron in presence of much per-mangmate may be checked by the addition of sodium phosphate tothe solution.The author has based a quantitative method of estimating organic:products on the results obtained from this investigation, The method,which is described in detail in the original, is applicable to the estima-tion of commercial organic substances, the determination of t8heorganic matter in potable waters and in the waste liquors from worksemploying organic products, whilst for the estimation of alcoholicsolutions when largely diluted, it is more rapid than the sp.gr.method.I n the second part of the paper, the author treats cf the oxidationof organic substances by means of manganese dioxide in acid soll;tion,as well as of oxidations by permanganate in neutral and alkalinesolutions, and of analytical methods derived therefrom.The Stalagmometer : a New Method for the Determinationof Fuse1 Oil in Spirituous Liquors. By J. TRAUBE (Rer., 20,2644--2655).-The author previously described (Abstr., 1886, 743) amethod for determining fuse1 oil in brandy by observing the heightof the solution in a capillary tube. In the present paper an apparatus,D. B92 ABSTRACTS OF CHEMICAL PAPERS.called n “stalagmometer,” is described by means of which the percentageof fusel oil is determined by counting the drops contained in a kiiownvolume of liquid.As in the older method, the brandy is first dilutedso as to be about 20 per cent. It is then put into the stalagmometer,and the number of drops from a given volume observed and com-pared with the number obtained from the same volume of pure 20 percent. alcohol. An excess of 1% drop to 100 C.C. of liquid shows thepresence of 0.1 per cent., an excess of 3.5 drops, of 0.2 per cent. offusel oil. 0.05 per cent. of fusel oil can be determined readily andwith certainty.To increase the delicacy of the method, the proportion of alcoholt o fusel oil must be diminished. This is done in the followingmanner:--300 C.C. of the liquid to be examined (diluted to 20to 25 per cent.) is shaken in a funnel with 110 ta 120 grams ofpure ammonium sulphate, and left until two layers are formed;the lower layer, which contains vePy little fusel oil, is drawn offand shaken with two to three drops of’ ethyl alcohol. or some crystalsof ammonium sulphate.In this way the rest of the fusel oil isobtained as a separate laeyer. These upper layers are now mixed,dissolved in water, and distilled to about two-thirds. The distil-late is made u p to 110 c.c., the alcohol determined by meansof A Westphal’s balance, and the number of drops contained in thevolumc V by means OF the stalagmometer. The latter number iscompared with that obtained from pure spirit containing a knownamount of fusel oil.A sketch of the apparatus is gicen, as well 3s results obtainedby means of it.These show that the method is as accurate as thatpreviously described (Zoc. cit.), the new method having the advantageof being more easily worked. N. H. M.By J, MUTERand L. DE KOXINGH (Anulyst, 12, 191--195).-CarboZ~c Powders.-Where the phenols exist in the uncombined state, they are extractedby methylated spirit from 75 grams of the powder. Where thepowder contains a lime base, a preliminary thorough trituration witha small excesR of dilute sulphuric acid is necessary. The alcoholicextract is mixed with 200 C.C. of a 5 per cent. solution of sodiumhydroxide, and the mixture is then evaporated to half its bulk. Atthis point any tar oils and naphthalene will separate and are to befiltered off. The filtrate is further concentrated to 50 C.C.and trans-ferred to a graduated tube. This, which is known as Muter’s car-bolimeter, is wide in the lower portion. At 65 C.C. it is narrowed toa neck, which is graduated up to 110 C.C. in 0.35 C.C. divisions. It isstoppered, and is furnished with a long, thin, stirring rod, the volumeof which must be allowed for. The solution is made up to 6.5 c.c.,25 C.C. of strong hydrochloric acid are slowly added with stirring,and then enough dry common salt t o render the phenols insoluble.The tube is plunged into water of 15.5’ and the volume of the phenolsread off.Liquid Oarbolic Acid.-If this contains excess of watep, it will notgive a clear solution with three volumes of benzene. The amount ofAssay of Commercial Carbolic CompoundsANALYTICAL CHEXISTRY.93water is ascertained by shaking 20 C.C. of the sample with 80 C.C. of asaturated solution of sodium chloride, and observing the diminntionin volume. Tar oils are estimated by shaking 20 C.C. with 80 C.C. ofmda solution (5 per cent.), and a small quantity of benzene (10 C.C.for dark specimens, less for pale ones). The increase in the volumeof the benzene gives the amount of t a r oils. The remainder i, takenas phenol and cresols. M. J. s.Acidimetry with Red Wines. By TONY-GARCIN (Comyt. read.,105, 577).-When red wine, prepared in the ordinary way and notmore than a year old is mixed with sodiam hydroxide solution, thecolour changes to carmine, which becomes deeper and duller andpasses into violet-black, which afterwards becomes black, withoutany tinge af violet, and then changes to green, with formation of adark, flocculent precipitate.The point a t which the colour is brownish-black, without any tinge of violet or green, is the point of exactneutralisation. C . H. €3.Dairy Products. (Bull. U, 8. Agrz‘c. Depart., No. 13, 1-128).-Butter and its Substitutes.-A series of micro-photographs is given,showing the appearance presented by butter, &c., when examined bypolarised light. The black cross described by Hehner and Angel1 isseen in all the specimens of butter prepared by boiling and slowcooling, and is almost uniformly absent from the crystals obtainedfrom the other fats, nevertheless it is shown by some specimens ofbirtterine and oleomargarine from Armour and Co., Chicago, as well asin a slide prepared from beef suet “oleo oil,” by dissolving in hotalcohol, and cooling slowly, thus confirming the opinion that it is notto be trusted as a characteristic of genuine butter.The following method for determining the melting point of fats isdescribed :-Thin discs are obtained by dropping the melted fat on toa piece of ice.One of these is placed in a test-tube, t h e lower partof which contains boiled water, and the upper part strong alcohol.The disc floats between the two liquids. The tube is then warmed ina water-bath, whilst the temperature of the contents is taken by athermometer with small bulb, situated just above and close to thedisc, and kept in motion like a revolving pendulum. The ternpera-ture a t which the disc contracts to a sphere is taken a s the meltingpoint. It is necessary to examine the discs when freshly made, asthey show a higher melting point if kept for 24 hours.When thewater-alcohol tube is warmed before dropping in the disc, the con-traction takes place some 6” lower than when the former method isfollowed.Daven-port saponifies 5 grams of the butter with only 10 C.C. of alcoholicpotash (cont,aining 2 grams of KHO), operating in a flask from wThichthe alcohol vapour is aspirated by a water-pump. Saponification andevaporation to dryness are complete in 15 minutes, and from thestatement that genuine butters treated thus require on an average28.8 C.C. of - alkali, there would appear to be no loss of ethyl buty-Various modifications of Reichert’s process are described.Nl 94 ABSTRACTS OF CHEMICAL PAPERS.rat'e (compare Allen, Abstr., 1857, 1145).Crampton substitutesphosphoric for sulphuric acid in the distillation, but finds that withcare the two give identical results.Scheffer's test for foreign fats is based on the solvent action of amixture of amyl alcohol (40 vols.) and ether of sp, gr. .On715 (60 vols.).1 gram of butter dissolves in 3 C.C. of this mixture at 28" ; 1 gram oflard requires 16 C.C. ; 1 gram of stearin 350 C.C.The following order of value is assigned to the various modes ofexamining butters for adulteration :-( 1.) Determination of volatileacids. (2.) Determination of specific gravity. (3.) Determination ofsaponification equivalent (Koettstorfer). (4.) Determination of theinsoluble acids (Hehner, Muter, Blyth, &c.X ( 5 .) Det,errnination ofthe melting point.A complete bibliography of butter analysis (up to 1882) is given byCaldwell (Seeond Ann. Rep. N . Y. S. E d . of B e a l t h , ,544-547), andi n Sell's Kunstbutter (Arbeit a. d . R a i s e d . Geswndheitsumte),MiEk.-For the determination of water, Babcock employs asbestos toabsorb the milk before drying; this is much to be preferred to anypowder, By placing the asbestos in a, tube between plugs of cotton-wool, and drawing air through the tube wbile it is heated a t loo", thedesiccation is complete in two hours. The tube can then be transferredto the f a t extractor,Of methods for the determination of the fat, the preference is givent o that of Adams (Abstr., 1886, 583), but instead of soaking up themilk with one end of the roll of paper, the plan has been adopted ofholding the unrolled strip in a horizontal position, and running the5 C.C.of milk from a pipette along the middle. The strip is thenhung up in a hot chamber, and in two or three minutes is dry andready for rolling up.In Soxhlet's araometric method (Abstr., 1881, 656) great difficultywas encountered in ensuring the separation of the ethereal fat soln-tion, and any long delay in the separation was found to affect thefinal results. By placing the bottles containing the mixture in acentrifugal machine revolving about 300 times per minute, the timerequired for separation was reduced to a few minutes, only six samplesout of 150 requiring more than quarter of an hour.The fat solutionthus separated had, however, a lower specific gravity than thatobtained by simple subsidence, so that the percentage of fat as given inSoxhlet's table had to he increased by 0*1:3, to bring it into agreementwith the results of the older method. Cronander also separates thefat by shaking the milk with potash and ether, hut evaporates theether after i t has risen to the surface of the milk, and measures thefat by forcing it in a melted state into a graduated tube.Pleischman and Morgen calculate the fat by the formula-100s - 100S-'f = 0.833 - 2.22where f = percentage of fat, t = percentage of total solids, S =specific gravity of the milk a t 15".Morse and Piggot add 10 C.O.of milk to 20 grams of dehydratedcopper sulphate. The fat The milk becomes dry in a few momentsANALYTICAL CHEMISTRY. 95i a then extracted by light petroleum, and its amount determined(after evaporation) by saponification.It is agraduated glass cylinder, containing in its lower part a amalleycylinder of white glass with black lines on it. 4 C.C. of milk are putjn the cylinder, and water is added until the black lines becomevisible. The reading of the total rolume gives at once the per-centage of fat.For the determination of the free acid in konmiss, it bright filtratewas obtained by adding to the koumiss an equal volume of alcoholOf lactoscoyes, Feser’s is said to be the most convenient.before filtering.B!. J. s.Extraction of Fats by Soxhlet’s Apparatus. By J. M. MILNE(J, SOC. C‘hem, Ind., 6, 34).-1n using the apparatus for milks, theauthor procwds as follows :-About 10 C.C. of the milk is weighedinto a tared porcelain basin, and the milk evaporated with frequentstirring in arder to render it granular, until on being cooled theresidue is semi-solid. The residue is then transferred to a paper cupand placed into the Soxhlet tube, and the fat extracted with ether inthe usual way, The author having worked with Adams’ paper coilsfor drying np milk for fat extractions, confirms the fact pointed outby the committee of the Society of Public Analysts, that from 0.3 to0.5 per cent. more fat is extracted by the coil method.Examination of Wines and Oils.Ry P. SPICA (Gszzetta, 17,304--312).-The author at the outset; makes the oft-repeated com-plaint that the conditions, such as the variation of concentration, oreven the nature of the acids used, required for the successful applica-tion of test-reactions, are not defined wit.h sufficient exactness inoriginal papers. Various processes have been proposed to recognisethe colouring matters, whether natmal or artificial, of wines ; butpreference is given by the author to the methods proposed by Caze-neuve (AbRtr., 1886, 397), Arata (Gazzetta, 17, 44), Blarez andDeniges (Abstr., 1886, 1084), and Girard and Gautier. In the last-named process the substitution of tablets of Mugnesisc aZba for thoseof plaster of Paris is suggested ; hhese are immersed in egg albuminfor a shart time and dried. A drop of the wine to be examined is letfall on such a prepared tablet, and the colour of the stain produced isobserved.The natural colouring matters of wine give a yellowish-brown, those containing rosaniline or ‘‘ vinoline ” a reddish-jellow,those with indigo an azure-green, with orchil a violet red, and thosewith amaranth a greyish-violet stain. Another method suggested con-sists in shaking up the wine with barytn-water and amyl alcohol,when the latter extracts the colouring matter from the wine. Itappears that certain preparations containing coal-tar colouring mat-ters, called “ vinoline,” are sold by druggists in Padua. An examina-tion of such a, preparation, called “maroon vinoline,” was found toconsist of about 40 per cent. of mineral matter, in which arsenicwas present in considerable quantities.As regards the method of examination of oils proposed byMaumen6, which is founded on the rise of temperature when theD. B96 ABSTRACTS OF CHEMICAL PAPERS.sample is mixed with concentrated sulphuric acid, it appears that aconfusion has arisen between grams and cnbic centimetres. Con-cordant results are obtained with mixtures of 50 grams or 55 C.C. ofoil with 10 C.C. of acid.Bechi has proposed a method for the recopnit'ion of cotton-seedoil in 01iv.e oil. which consists in adding to the oil an alcoholic-etherealsolution of silver nitrate in presence of an amyl alcohol solution ofpetroleum ; it is here shown that this method gives fallacious results.A method of the greatest practical value is that proposed by Hubl,which has given satisfactory results in the hands of Moore, Allen,Oglialoro, and other observers.Gravimetric Estimation of Tannins. By H. R. PROCTER(J'. Xoc. Chem. Ind., 6,94--96).-The process described by the authoris a combination of the methods published by Muntz and Simand,and depends on the fact that in filtration through a column of dryhide powder the upper layers absorb most of the tannin, a very com-plete and rapid separation being obtained from the large surfaceexposed. The author utilises the lamp chimneys employed in thecommon round-wicked German petroleum lamps, which are con-tracted just above the base of the flame and are cylindrical for the re-mainder of their length. A perforated disc of cork is made slightlycup-shaped on its two faces. A piece of linen is then stretched overit, and i t is pressed down the chimney until i t rests on the contractedneck. Five grams of hide powder is weighed into the tube, andwhen shaken down will occupy a space of about 50 C.C. The tube isnow cut off, allowing only length for the insertion of a cork, whichmay press slightly on the powder, as it contracts in volume when wet.This cork is perforated and hollowed like the first, and after beingcovered with linen is pressed into the tube. A short piece of quilltubing passes through the cork, and is fitted by a second cork into aflask. The filtering tube is inverted, broad end downwards, into abeaker of 100 C.C. capacity, which is filled with the liquid to befiltered until it rises into the hide- powder. The tube is left in thisposition for one or two hours, after which it is reversed, and theenlarged end filled with the solution, when the filtration will be foundto proceed evenly and steadily. The filtrates thus obtained are per-fectly free from tannin, and tested by,the Lowenthal method show alower result for " aon-tannin " than those by any other method of ab-sorption. The method is, however, inapplicable in the presence ofgallic acid, t,he latter being freely absorbed by hide powder. Theauthor hopes to overcome the difficulty either by some method ofV. H. V.removing the gallic acid or of preventing its absorption by the hide.D. BJaum . Chem .Sue. Feb. 1888. BALLNo 3 .Harrison & Suns. Lith. S. Murtins Lane. W.C