PORCELAIN .... net 5 o Blowpipe Analysis. By F. H. Getman.. 60 7 6 8 6 net 2 6 HALDENWANGER Can be obtained from all businesses which deal in Chemical Apparatus. London: Printed and Published for the Proprietor by EDWIN JOHN DAVEY, at the Office, 16, Newcastle Street, Farringdon Street, E... July 8, 1910 Edited by AND JOURNAL OF PHYSICAL SCIENCE Established ir Wm. Crookes, F.R.S.] (WITH WHICH IS INCORPORATED THE "CHEMICAL gazette") [Sixty-seven tears Published Weekly. Annual Subscription, free by post, £1. Entered at the New York Post Office as Second Class Mail matter. Vol. 102.-No. 2642. [Copyright ARTICLES: Friday, July 15, 1910. 25 reserved. CONTENTS. PAGE Occurrence of Formaldehy le ia Sugar-cane Juice and in Sugarhouse Products, by P. A. Yoder and W. G. Taggart PROCEEDINGS OF SOCIETIES The Influence of Chlorine upon the Determination of Nitric ..... .... 25 .... 26 THE ROYAL SOCIETY................................ 29 31 36 36 MISCELLANEOUS 36 C. PASS AND SON, LIM., BRISTOL, Are Buyers of LEAD ASHES, SULPHATE OF LEAD, LEAD SLAGS, ANTIMONIAL LEAD, COPPER MATTE, TIN ASHES, &c., ORES, DROSS, or RESIDUES, containing TIN, COPPER, LEAD, and ANTIMONY. FOR SALE. Registered as PRICE 44. Chemist, Swiss, aged 23, Diploma of the Polytechnikum, Zurich, speaking German, French, and English, desires Post in English factory, Has some experience in Technical' Analysis.-Address, A. Z., CHEMICAL NEWS Office, 16, Newcastle Street, Farringdon Street, London, E.C. Muriatic Acid, Sulphuric Acid, Bicarbonate of Soda, Muriate of Ammonia. AGENCIES (on Commission) for these and other CHEMICALS suitable for manufacturing purposes in Staffordshire, Warwickshire, Worcestershire, and Shropshire, also Agency for SPELTER, desired by man of twenty years' business experience and of sound position.- Address, "Agency," CHEMICAL News Office, 16, Newcastle Street, Farringdon Street, London, E.C. A LAMBERT TYPEWRITER, complete in Institute, Belfast. solid Leather velvet-lined Carrying Case, all in perfect order and excellent condition. Listed at £7 78., to be sold for £3.-Address, L. T., CHEMICAL NEWS Office, 16, Newcastle Street, Farringdon Street, London, E.C. OZONE mittee invite applications for the position of PROFESSOR of PURE and APPLIED CHEMISTRY at the Municipal Technical Commencing salary £350 per annum, increasing to £400 per annum. Particulars of the Duties and Conditions of Appointment may be obtained from the undersigned, with whom applications, on the special forms provided for the purpose, must be lodged not later than noon on THURSDAY, AUGUST 11th, 1910. (Time extended from July 20th, the Canvassing is forbidden, and will disqualify. Municipal Technical Institute, Belfast. APPARATUS. date previously announced). Refer to OZONAIR, Ltd., 96, Victoria Street, London, S.W. FRAS. C. FORTH, Principal. PLATINUM Utensils. We supply all forms and sizes of Platinum Utensils and Apparatus for Chemical and Physical purposes. All our utensils are hammered to shape, tested, and finished in the best manner. All kinds of Platinum scrap bought for cash or taken in exchange for new. - DERBY and CO., Ltd., 44, Clerkenwell Road, London, E.C. T. TYRER & CO., Ltd.,' Stirling Chemical Works, CHEMICALS for Analysis, Research, and Technical purposes. on a MANUFACTURING SCALE. Inquiries solicited from INVENTORS and PATENTEES (especially Foreign) under the New Act, 1906. GRIFFIN KINGSWAY, LONDON, W.C. KAHLBAUM'S PURE CHEMICALS. Price List & Particulars on application THE NOW READY. Cloth, 216. Paper covers, 316; (Postage, 4d. extra). THE WHEAT PROBLEM: Based on Remarks made in the Presidential Address to the British Association at Bristol in 1898. REVISED WITH AN ANSWER TO VARIOUS CRITICS By SIR WILLIAM CROOKES, F.R.S. VITH PREFACE AND ADDITIONAL CHAPTER, BRINGING THE With Two Chapters on the Future Wheat Supply of the OPINIONS of the PRESS. "The book is a useful one to all interested in the production of wheat both from the commercial and scientific points of view."-Knowledge. "Sir William Crookes's statistics seem to make good his alarmist statement."- British Weekly. "The student of economic science and sociology will find this volume full of interesting material. . The entire subject is of the profoundest interest, and an excellent pur pose has been served by the publication of these papers in a single volume."-The Eagle (Brooklyn, N.Y.). "Sir William discusses at length the criticisms passed upon his address, and he appends valuable papers supporting his arguments on the future wheat supply of the United States."-Globe. "It is a vital question, and considering the cheap issue of the volume all interested in the feeding of the millions ought to get it and read it carefully."-Crieff Journal. "Sir William Crookes .. has propounded a problem which in the next century [written in 1899] is bound to engage the close attention not merely of agricultural experts, but of economists and statesmen."-Speaker. "The appearance of the papers in this convenient form will be welcome to everyone who appreciates the importance of the problem."-Scotsman. "In the present volume Sir William Crookes replies vigorously to his critics."-Liverpool Daily Post. 16, NEWCASTLE ST., FARRINGDON ST., E.C. OLD PLATINUM IN ANY FORM PURCHASED FOR CASH. 40 and 42, CLERKENWELL ROAD, E.C. Photographic Residues Reduced and Purchased. SULPHUROUS ACID and SULPHITES. Liquid SO2 in Syphons, for Lectures, &c. PHOSPHORIC ACID and PHOSPHATES. CARAMELS & COLORINGS for all purposes. A. BOAKE, ROBERTS, & CO. (LIMITED), Stratford, London, E. CHEMICAL NEWS, July 15, 1910 Oxides of Iron and Alumina in Florida Phosphates. THE CHEMICAL NEWS VOL. CII., No. 2642. THE INFLUENCE OF CHLORINE UPON THE DETERMINATION OF NITRIC NITROGEN. By ROBERT STEWART snd J. E. GREAVES. IT is known that chlorine has an appreciable effect upon the determination of nitric nitrogen by the phenyldisulphonic acid method. Very little information, however, is available as to the amount of chlorine which may be present and not affect the reliability of the results. In connection with the study of the influence of irrigating water upon the movement and production of nitric nitrogen in the soil, this question was investigated quite thoroughly in this laboratory (Utah Experiment Station, Bull., cvi., 80). The results are of interest to others working along similar lines, and also to chemists who are working with problems in sanitary water supply. The chlorine in the soil under consideration was determined as follows:-An aliquot portion of the extract of the soil, prepared as for the nitric nitrogen determination, was titrated against a one-hundredth normal silver nitrate solution. The results obtained are given in Table I. The results are expressed as parts of chlorine per million parts These results indicate quite clearly that the chlorine in the soil under consideration did not exceed 1134 parts per of soil. million. usual way. 25 The results are very interesting, and will be found in Table II. The results are expressed as parts per No Similar determinations were made until a concentration of thirty parts per million of chlorine was reached. further decrease in the amount of nitric nitrogen found was obtained; i.e., the amount of nitric nitrogen found tended to approach a constant value of nine-tenths of the amount actually present. The results show that chlorine, when present in quantities as low as 2.638 parts per million, affects the results for nitric nitrógen obtained by this method, less nitric nitrogen being found than is really present.-Journal of the American Chemical Society, xxxii., No. 6. THE DETERMINATION OF OXIDES OF IRON AND ALUMINA IN FLORIDA PHOSPHATES. By H. HERZOG. THE method as given below is a modification of the old Glaser method, and can be depended upon to give excellent results in all except the few instances in which manganese occurs in any appreciable quantity. It must also be noted that this method does not include any iron or alumina present in the shape of pyrite, or as a silicate insoluble in acid. With reasonable care in the various operations, the results on the identical pulverised sample should not differ more than o'05 per cent, and are generally well within this limit. The most important points appear to be the proper elimination of fluorine, and the use of very hot water in washing the precipitate. As carried out in this laboratory, the operations are as follows: One grm. of the powdered sample is carefully weighed out and placed in a tall beaker of about 300 cc. capacity. Ten cc. of strong muriatic acid are added, and after covering with a watch-glass, the beaker is placed on a gauze and quickly brought to a boil. Leave on the gauze for ten minutes, regulating the flame so that it does not go dry, and the bulk of the solution at the end of the ten minutes is about 5 7 cc. Let cool, and carefully decant as completely as possible into a Jena glass volumetric flask of 100 cc. capacity. Try to get all the solution to run into the flask, excepting the last drop or so. Rinse this last drop into the flask with the least possible amount of water. It is possible to do this with a little practice, without disturbing the bulk of the sand, which remains (most of it) in the original beaker. You now have about 10-12 cc. solution in the little volumetric flask. To this solution in the flask you add to cc. of dilute sulphuric acid (one-half acid of 1.84 sp. gr. and half water). The addition of this acid will form a curdy, bulky precipitate of impure sulphate of lime. Shake up the flask to mix this precipitate, and then place the flask on a gauze over Bunsen in the hood, and boil for at least ten minutes. It may require a little practice to get the flame just right, to get the flask and contents to boil hard without bumping off the stand-but it is most important that the contents should boil. This boiling gets rid of nearly all the fluorine, and changes the bulky precipitate of calcium sulphate into a dense crystalline compound, which filters and washes easily. My experience has been that a gauze and Bunsen are better than hot plate or sand-bath for this particular operation, as a quick heat gets the solution to a temperature where the violent pumping (caused by the occasional liberation of a large bubble of vapour) is avoided by causing the evolution of steam, &c., to be so rapid as to form a more continuous stream. After ten minutes' boiling, take the flask off the fire and let cool to room temperature. To go back to the beaker in which the original solution was made, it is possible that the grains of sand and insoluble matter might not have been rinsed quite clean in transferring to the flask. It is therefore the practice to OCCURRENCE OF FORMALDEHYDE PRODUCTS. add to this residue a few cc. of alcohol (95 per cent). These alcoholic rinsings are now added to the cooled flask IN SUGAR CANE JUICE AND SUGAR-HOUSE containing the dense calcium sulphate, and the solution made up to the mark with alcohol and allowed to stand at least one hour. (It will not hurt to stand over night). There is some shrinkage in this alcoholic solution, which must be made up to the mark with more alcohol. By P. A. YODER and W. G. TAGGART. IN an investigation on some minor constituents of the After standing the solution is filtered on a dry filter into sugar-cane and sugar-house products, we diverged from a dry beaker, or into a dry porcelain evaporating dish of the main branch of the problem pursued (the acid conabout 5 inches diameter, if all the solution is to be used. stituents) to investigate the occurrence of formaldehyde, In case the flask is graduated to allow for the bulk and incidentally for the further elaboration of a method for Occupied by the calcium sulphate precipitate, the dry quantitatively estimating small amounts of formaldehyde. beaker is used to catch the filtrate—and an aliquot portion | We were led to this side-line investigation by a consideraof 75 cc. is withdrawn with a pipette, and this aliquot | tion of the facts (1) that formaldehyde is very convenient (corresponding to grm.) is used for the further tests. If to use, and frequently is used to preserve fresh juice in you have not allowed for the bulk of the precipitate, it the sugar-house when boiling is interrupted from any cause; will be necessary to filter all the solution from the flask, (2) that it is recommended by some as a clarifying agent; and wash it with alcohol until free from foreign matter. (3) that formaldehyde is objectionable in food products; Assuming that you have withdrawn 75 cc. for analysis, and (4) that it has never, so far as we know, been proved, place this in the 5-inch evaporating dish, and then place but is generally assumed that it all boils away in the the dish in a pan containing about one-half inch in depth evaporation of the juice to a massecuite. Further comof water. This water is used simply for cooling purposes, plicating the problem are some recent reports that in and must not be too deep, or your dish will be liable to caramelising sugar, or even in boiling sugar solutions, crack. Now add about 5 cc. of bromine water to your formaldehyde is formed. Trillat (Comptes Rendus, cxlii., alcoholic solution, pouring it down the side of the dish 454; Chem. Centr., 1905, i., 18, 131, 1178, 1423; 1906, carefully, so it will run under the alcoholic solution, with-i., 917, 1193; Zeit. Ver. Rübenzucker Ind., 1906, 93; Bull. out mixing any more than can be helped. Then simply de. l'Assoc. des Chim. de Sucr. et de Dist., xxiii., 649) and light the alcoholic solution with a match. The alcohol A. A. Ramsey (Fourn. Roy. Soc. N.S.W., 1907, xli., will burn off in from 10-15 minutes. The water outside 172; Intern. Sugar Journ., xi., 100; Bull. de l'Assoc. des prevents the solution from getting too hot and spattering. Chim. de Sucr. et de Dist., xxvi., 587) report thus. Chas. When the solution has burnt out and cooled, add 10 cc. H. La Wall (Am. Journ. Pharm., lxxxi., 384; Chem. concentrated solution of ammonium chloride. A few drops Abstr., iii., 2836) calls into question the conclusions of of rosolic acid solution as indicator are now added, and Trillat and Ramsey, pronouncing the test which the latter ammonia water till distinctly red. used as unreliable. That formaldehyde can form unstable compounds with some of the sugars has been reported by several investigators. Lippmann (Chem. d. Zuckerarten, ii., 1320) mentions such a compound with cane-sugar. The dish is transferred to the water-bath, and heated until the red colour is changed to a yellow. A little hot water is used to mix and dissolve any crusts that may have formed. Use water as hot as possible, and just before putting on the filter add ammonia very cautiously till it is faintly pink, and mix well by squirting in a fine stream from your wash-bottle. Then throw on a good tight 12 cm. filter (either S and S 589 or Munktell's oo) and let it all run through before adding the rinsings from the evaporating dish. The washing should be done without disturbing the layer of precipitate on the filter, and the water used should be as nearly boiling as possible. Usually (unless the percentage is very high), about three to four washings are sufficient to remove all the foreign matter. The moist precipitate on the filter is now placed in a 20 cc. platinum crucible, and dried over a very low flame. Then it is charred at a low red (don't let it catch fire) and finally ignited over a good Bunsen. The weight of this precipitate is equivalent to the weight of the phosphate of iron plus phosphate of alumina. In most of the older contracts one-half of this weight was the figures referred to when speaking of oxides of iron and aluminium "combined." It must be remembered, that in case only 75 cc. were operated on, that correction should be made to figure proper percentages from to 1 grm. This matter of taking one-half the weight of the phosphates to be the oxides of iron and alumina, "combined," has been sanctioned by custom, but is manifestly incorrect. It is therefore necessary to separate at least the iron in order to get at the actual percentages. To do this the ignited oxides in the platinum crucible are dissolved in dilute sulphuric acid on the hot plate. The solution takes place easily, leaving only a skeleton of filter ash. This solution can be made up to 100 cc., and the iron titrated in, say, 50 cc. with permanganate, and in the other 50 cc. the phosphoric acid, or the alumina, may be determined. Then it is a simple matter of calculation to get at the actual percentages of iron and alumina in the sample under examination.—Journal of Industrial and Engineering Chemistry, i., No. 7. | The preliminary work on the detection of the formalde. hyde in sugar-house products and on the quantitative methods for its estimation was done by us jointly, the junior author carrying out most of the laboratory tests. The working out of final details of the quantitative method used and its application to the juices and sugar-house products reported here was done by the senior author, who alone and in a private capacity is responsible for the formulation of this report and the conclusions drawn. Methods for Detecting and Estimating. Formaldehyde.— Of qualitative tests for formaldehyde there is no lack, and many of them are exceedingly delicate. The reliable quantitative methods usually mentioned in text-books, e.g., the KCN and AgNO3 method, or the H2O2 acidimetric method, are not sufficiently delicate to use with the very small quantities with which we found it desirable to work. Hehner's test with milk and concentrated H2SO4 containing a trace of iron, as well as a similar test with HCl, seems to be characteristic of formaldehyde, and so delicate for qualitative work that we were led to look hopefully to modifications of these for a quantitative method which, even if not extremely accurate, is sufficiently accurate and delicate for our purposes. F. W. Richardson (Journ. Soc. Chem. Ind., xxvi., 3 and 4; Chem. Abstr., i., 750) modified Hehner's method to make it colorimetrically quantitative, using in place of milk a clear solution containing albumose, which he prepared by incompletely digesting egg albumen with a solution of pepsin and HCI. Seeking a similar substitute for milk in the method with ferruginised concentrated HCl, we tried first a solution of dried peptone, such as is used in bacteriological laboratories. This worked so satisfactorily that we did not take further trouble to prepare partly digested albumen. Substituting this peptone solution for milk, we had a very delicate reagent, and the resulting coloured solutions were so clear as to be well adapted for comparisons in Nessler's tubes. In the preliminary work, 1 cc. of the distillate or other solution to be tested was mixed with 5 cc. of a 1 per cent peptone solution and 5 cc. of concentrated HCl containing |