Add 30 cc saturated solution ammonium chlorid, add water, filling the beaker to within about three-fourths of an inch from the top, place in water bath and heat to 70°. Remove from bath, add 5 or 6 drops of methyl orange solution, and then add ammonium acetate solution which has been heated to 70° until color changes from red to yellow. Add an excess. Filter on folded filter, and wash two or three times with hot 5 per cent solution of ammonium nitrate; dissolve this precipitate back into the same beaker, using diluted hydrochloric acid and hot water. Add 1 gram of ammonium phosphate to the solution and precipitate with ammonium acetate, proceeding as before. Filter and wash the last precipitate with 5 per cent solution of ammonium nitrate five times and once with hot water. TABLE III.-Determination of alumina by the thiosulphate method and Method described by ref- Per cent. modifications. [The totals are averages.] 5.45 5.30 5.25 5.51 5.30 5.25 5.34 5. 34 Per cent. We have not done sufficient work by the modified acetate method to vouch for its accuracy, but we believe that with some slight modifications it will be an ideal method. The advantage this has over the regular laboratory method, which we have previously used, is the elimination of any considerable amount of lime from the precipitate. In method No. 1, unless great care is taken in the manipulation, there will be some lime left in the precipitate and the results will be correspondingly high. In the hands of different chemists, especially those with little experience, our method has not always given good results, but after having had considerable experience with the method the analysts usually get excellent results. PRELIMINARY STUDIES ON THE ANALYSIS OF BASIC SLAG FOR AVAILABLE PHOSPHORIC ACID. By H. D. HASKINS. The slag used for the following tests analyzed 19.02 per cent, 18.94 per cent, and 19.02 per cent total phosphoric acid, or an average of 18.99 per cent. In view of the fact that it is generally conceded that the beneficial effect of Thomas slag phosphate on growing vegetation may be due, in part at least, to the free lime present in the slag, it occurred to the writer that the fairest way of treating the slag for the determination of the available phosphoric acid was first to neutralize the free lime and finally treat the resulting product with neutral citrate of ammonia in the usual manner. This was accomplished by the two following methods: Method A.-Two grams of the Thomas phosphate powder were weighed into an Erlenmeyer flask of 150-200 ce capacity, 10 cc of distilled water and a few drops of phenolphthalein solution as an indicator were added. The flask was then placed on a boiling water bath and when the solution became thoroughly heated, dilute citric acid was run into the flask until the pink color disappeared. After the mass had been brought to dryness, 100 cc of neutral citrate of ammonia were added and the digestion was carried on at 65° C. in the usual way as for the determination of citrate-soluble phosphoric acid. This method showed 6.61 per cent and 6.29 per cent of available phosphoric acid. Method B.-Two grams of the Thomas phosphate powder were transferred to a small beaker, 10 cc of distilled water and a few drops of phenolphthalein solution were added and the beaker was placed on a boiling water bath. When hot, an excess of dilute citric acid solution was added and the mass was digested for fifteen minutes on the hot water bath; the solution was then filtered into a 200 cc flask and washed with hot water until it was up to the 200 ce mark. The residue was treated with neutral citrate of ammonia in the usual way and showed 6.83, 6.37, and 6.60 per cent of available phosphoric acid. The citric acid solutions that had been filtered off showed about 0.06 per cent of phosphoric acid. Another set of samples was run according to method B, only a larger excess of citric acid was used in the digestion. The citric acid solutions upon being analyzed showed 1.40, 1.66, and 1.48 per cent of phosphoric acid. The residues showed 6.13, 5.71, and 5.40 per cent of citrate-soluble or reverted phosphoric acid, making the available phosphoric acid in this case 7.53, 7.37, and 6.93 per cent. It was noticed when the residue from the citric acid solution was being washed with hot water, that after a few washings the water, as it left the residue, was of a pinkish color. The sample of slag on which the above tests were made showed 47.83 and 47.72 per cent or an average of 47.77 per cent of calcium oxid of which 7.38, 7.40, and 7.43 per cent were actually found present as free calcium oxid. No attempt was made to determine the available phosphoric acid in the above slag by the method in use at the California experiment station or by the Wagner method. It appears to the writer that of the two methods, Method B offers the most encouragement for development. Although not giving satisfactory concordant results, as above outlined, it would seem that if a given quantity of solution of citric acid of known strength were used in each case, satisfactory comparative results would follow. It is earnestly hoped that the association will investigate the matter of the determination of the available phosphoric acid in basic slag and adopt, at least provisionally, some method for the analysis of this product, the use of which is becoming general in certain sections of our country. REPORT OF COMMITTEE B ON RECOMMENDATIONS OF REFEREES. B. B. Ross, Chairman. (Dairy products, foods and feeding stuffs, sugar, tannin, and medicinal plants and drugs.) (1) SUGAR. It is recommended- (1) That in the determination of reducing sugars the use of lead subacetate as a clarifying agent be discontinued and that only those agents, such as normal lead acetate, be employed which do not precipitate reducing sugars. Adopted. (2) That the use of potassium oxalate for precipitating the excess of lead from sugar solutions before polarizing or determining reducing sugars be adopted provisionally. Adopted. (3) That the zinc oxid method for the determination of ash in molasses be dropped from the official methods. (Bul. 107, p. 68, Method II.) Adopted. (4) That the method and tables of Munson and Walker for the unification of reducing sugar methods be adopted provisionally by the association. (J. Amer. Chem. Soc., 1906, 28: 663; 1907, 29: 541.) Adopted. (5) That Low's volumetric method for the estimation of reduced copper (Bul. 99, p. 19) be made a provisional method of the association. Adopted. (6) That the question of the influence of normal lead acetate, of wet and dry lead subacetate, and of hydrosulphite upon the polarization of sugars be further investigated. Adopted. (7) That the analysis of commercial dextrins be further investigated by next year's referee on special analytical methods. Adopted. It is recommended (2) FOODS AND FEEDING STUFFS. (1) That the method for methyl pentosans be further studied next year, especial attention being given to obtaining as much cooperative work as possible. Adopted. (2) That the table for calculating methyl-furfural-phloroglucid to fukose, fukosans, rhamnose, rhamnosans, and methyl-pentosans (average of fukosan and rhamnosan), given in an article by Mayer and Tollens (J. Landw., 1907, 55 (3): 269), be used in calculating the results of analysis; the average figure for methyl pentosans being taken when it is not known whether the mother product is fukosan or rhamnosan. Adopted provisionally. (3) That the last sentence under “Crude Fat or Ether Extract,” “(b) (1) Direct Method," Bulletin 107, Methods of Analysis, page 39, which now reads as follows: "Dry the extract at the temperature of boiling water until it ceases to lose weight," be changed to read: "Dry the extract at the temperature of boiling water for one-half hour, remove from the oven to a desiccator, cool and weigh; continue this alternate drying and weighing at half-hour intervals until a minimum weight of fat is obtained. For most feeds a period of from one to one and one-half hours is required to obtain a minimum weight." Adopted. [This is an elaboration of an official method and was adopted as a recommendation of the chairman of the committee on revision of methods, ordinarily two years being necessary for such action.] It is recommended— (3) DAIRY PRODUCTS. (1) That the study of methods of analysis of condensed milk be continued and that special attention be given to the following methods for determining the fat and sugar content of condensed milk: (a) Double extraction method for the determination of fat as described in the proceedings of the association for 1906. a U. S. Dept. Agr., Bureau of Chemistry, Bul. 105, p. 105. (b) Roese-Gottlieb method for the determination of fat as described in the proceedings of the association for 1906.a (c) Walker method for the determination of sugar. (J. Amer. Chem. Soc., 1907, 29:541. (d) Allihn method for the gravimetric determination of sugar. (e) Polariscopic method in comparison with the gravimetric method for the determination of sugar. (1) That work be continued with a view to finding a cheap strong filter paper as a substitute for S and S 590. (2) That the method of filtering soluble solids suggested by Reed be given further trial. (J. Amer. Leather Chemists Assn., 2: 420.) (3) That the referee take up the study of methods for the analysis of leather, as such methods are greatly needed. Recommendations adopted. It is recommended— (5) MEDICINAL PLANTS AND DRUGS. (1) That the present provisional method for assaying opium be made official. (Bul. 107, p. 201.) Referred to referee for recommendation as to final action in 1908. (2) That the methods included in the referee's report be made provisional. (See p. 81.) Adopted. (3) That the work be continued and that the associate referees be appointed on the following subjects: (a) Analytical methods for crude products. (b) Methods for detecting and estimating alkaloidal matter in mixtures. (c) Macroscopical and microscopical methods. (d) Microchemical methods. (e) Methods for headache mixtures. (f) Methods for determining alcohol in the presence of other volatile bodies. (g) Methods for testing volatile oils. After some discussion this motion was put to a vote and was lost, it being deemed inadvisable to create associate referees for such divisions of the subject at this time, and the referee was instructed to conduct the investigations specified informally, assigning the several lines of work to such chemists as volunteered for cooperative work. A motion was made to continue the committee for the testing of chemical reagents another year, and this motion was carried. Mr. Kebler called attention to the fact that it was often desirable to use the text of the United States Pharmacopoeia in connection with the association work on drugs, and this could not be done without the consent of the trustees of the Pharmacopoeia. It was moved, therefore, that the secretary of the association be authorized to correspond with the proper authorities and secure this privilege. The motion was carried. a U. S. Dept. Agr., Bureau of Chemistry, Bul. 105, p. 105. REPORT ON POTASH. 'By A. L. KNISELY, Referee. At the last meeting of the association it was recommended that the study of the volumetric method for use in both soil and fertilizer analyses be continued. It was also recommended that the referee direct his attention to a study of what really constitutes available potash in soils, fertilizers, and ground mineral products, to the end that available potash might be defined. The referee, assisted by Mr. C. E. Bradley, spent all of the time possible upon a study of the volumetric method, leaving the subject of available potash for consideration during the coming year. Considerable time was spent in preliminary experimental work upon details of the method before a satisfactory scheme was evolved as an outline for cooperative work. In applying the method of Donk for estimating potash volumetrically, approximately correct results can be readily obtained. At times, however, discrepancies were noted in comparing volumetric values with those obtained by gravimetric methods. One of the vital points in the process is the use of a wash liquid which will remove all excess acid from the precipitated potassium phosphomolybdate and at the same time dissolve only inappreciable quantities of this yellow precipitate. Accordingly a test was made to determine the solubility of the potash precipitate in both nitric acid and sodium nitrate under different conditions in respect to strength, time of contact, etc. For this purpose a quantity of pure potassium phosphomolybdate was prepared by adding phosphomolybdic acid to excess of potassium sulphate in solution and washing the precipitate with a weak solution of sodium nitrate. To determine the action of nitric acid upon this precipitate, 0.1 gram of potassium phosphomolyb date was placed in contact with 50 cc of the nitric acid of varying strength, well stirred and filtered. The filtrate was evaporated to dryness on a water bath and the residue titrated with potassium hydroxid. TABLE I.-Determination of the solubility of the potash precipitate in nitric acid. Heating to 50° C. is thus seen to exert marked solvent action, even with very dilute solutions of nitric acid. The cold acid of much greater strength exerts less solvent action, when time of contact is limited. The action of the nitric acid wash under different conditions was also tested on an official acid (sp. gr. 1.115) extract of soil. Ten cubic centimeters of solution, corresponding to gram soil, were evaporated with phosphomolybdic acid and the residue subjected to the following methods of washing: |