THE ANALYST. 39 REPORT OF RECENT RESEARCHES AND IMPROVEMENT8 fN ANALYTICAL PROCESS. ESTINATION OF IRON AND ALUMINA IN PHOSPHATES. (Zehech f. Anyew Chrnie, No. 1, '91).-The author having thoroughly tried Glaser's process (see ANALYST, 1890), thinks it may be improved by lessening the amount of sulphuric acid. The original process recommends 45 grammes of the strongest acid, but even if the sample solely consisted of calcic oxide, two grammes would be amply sufficient. As the memur- ing of strong sulphuric acid is troublesome, the author uses 10 C.C. of an acid which has been five times diluted. The author further thinks the quantity of phosphate used for analysis (-4 gramrnes) is too small, at least one gramme should be used. The actual procesEl is, then, as follows :- 10 grammes of the phosphate are dissolved in nitrohydrochloric acid, and the solu- tion diluted up to 500 C.C.50 C.C. (= 1 gramme) areevaporated to half the bulk, and while still hot, mixed with 10 C.C. of dilute sulphuric acid. 150 C.C. alcohol are next added, and the mixture allowed to settle for at least three hours. Claser thought half an hour sufficient ; but the author found this to be not long enough. The sulphate of lime is collected on a filter and washed with alcohol, the filtrate being collected in a Erlenmeyer's flask of half a litre capacity. The washing is finished when 10 drops of the washings, after dilution with an equal bulk of water, do not colour with methyl-orange, The filter and the precipitate is put into a platinum dish, the spirit is burned of, and the mass finally ignited and weighed, The alcoholic solution is distilled off to recover the alcohol (which, however must be re-distilled over potash), and the residue rinsed into a beaker.Slight excess of ammonia is then added, and this again completely boiled off. This is very important, a8 it prevents the co-precipitation of magnesia. The precipitate, consisting of ferric and alumina phosphates, is carefully collected on a filter, and washed four times with boiling water without disturbing it too much. If the washings should be turbid, washing with a very weak solution of neutral ammo- nium nitrate must be resorted to. The filtrate contains phosphoric acid, magnesia, beside#, of coume, sulphuric acid, and may be alkalies. The magnesium phosphate & R, JONES.40 THE ANALYST.sepamted by addition of ammonia, and weighed; but the phosphoric acid and alkaliea are best estimated in aliquot part of the original solution. Many analysts prefer to remove the phosphoric acid by molybdate, and finally weigh the pure oxides. The author thinks this a very good plan, providing the phos- phates of iron and alumina have been first isolated by Glaser’s process before treating with molybdate. The phosphate must, however, be free from organic matter, otherwise a little of the alumina will escape precipitation. L. DE I(. ESTIMATION OF NITROGEN IN PURE AND MIXED NITRATES. A. SULLWALD. (Chem. Zed., No. 99, 189O).-The author’s process (really a modification of Jodlbauer’s method) is as follows :--5 gram. of pure nitre, or 1 gram.of a mixture is put into a 150 C.C. flask and moistened with 05 C.C. of water. The addition of water serves to easier dissolve the substance, and. also to prevent the mass from getting too hot; by means of a long funnel 20 C.C. sulphophenylic acid (20 grams. of phenol in 500 C.C. sulphuric acid) are slowly added. After thoroughly cooling 2.5 grams. of zinc-dust are added, and after a quarter of an hour some mercury is added, and the whole gradually heated to boiling. The ammonia is finally estimated as usual. If a sufficiently large and suitsble flask is at disposal it is as well to distil off the ammonia from the same. Although this process gives perfectly correct results, it ia, according to the author, not quite so simple as the one proposed by 0. Farster, which is as follows :-*6 gram.of the nitrate is mixed with the usual precautions, with 15 C.C. of a 6 per cent. sulphuric acid solution of salicylic acid. When all is dissolved 5 grams. of hyposulphite of soda are added, and finally 10 C.C. of pure sulphuric acid and a little mercury. f;. DB E. ASSAY OE‘ COM~EROUL ALUMXNIUM. F. REGIELSBERCISR. (Zed& f. Angew Chm& NO. 1, 1891).-Klemp’s process, based on the volume of hydrogen evolved when the metal is dissolved in potash-ley, is not correct, because all samples of commercial aluminium contain silicon, which also liberates hydrogen. For instance, a cornmeraid sample aon- faining 98 per cent. Al., and 1.5 per cent. Si., will give a volume of hydrogen corre- sponding with 99.9 per oent, of aluminium. The author thinks it far better to carefully estimate the impurities in the metal, but if a direct estimation is required he proceeds as follows ;-Two grams. of the murmple are dissolved in a solution containing 15 grams. of pure caustic potash in a platinum vessel, and finally made up to 200 C.C. 50 C.C. ( = -5 grm.) are now boiled with a alighf excess of neutral ammonium nitrate, and the precipitated alumina collected and treafed as usual. Allowance must of course be made for any alumina or silica the reagents may contain. The alumina must be of oourse tested for silicat, h3C!LAImdER.-Mr. W. H. Stanger and Mr. Bertram Blount, of the Broadway Laboratory and Testing Works, Westminster, desire to correct a rumour which has become prevalent, by stating that the Mr. William Fox who is at present associated with them at the above a.ddress, is a member of the Institution of Civil Engineers, and not a practising analyst.