EXPERIMENT STATION VOL. VII. No. 4. Soil investigations have by no means received such attention from our stations as their importance demands. Much of the field work of the stations must necessarily give comparatively imperfect and valueless results, because it is not accompanied by studies of the soils experimented with. It is very unfortunate that stations which have for a number of years been carrying on field experiments with a great variety of crops have no records regarding the chemical and physical conditions of the soils when the experiments were begun, nor the changes which have taken place in the soils during the progress of the experi ments. It is hoped that the renewed interest in soil investigations, which seems to have been recently excited, may lead many stations to begin serious studies on this line. The area devoted to field experiments may well be contracted if this is necessary in order to afford opportunity for more thorough study of the soil. At the recent convention of the Association of Official Agricultural Chemists, which is briefly reported in this number of the Record, there was evidence, as in past years, of a lack of enthusiastic coöperation in the testing of methods. This must cause genuine regret to all who are interested in the advancement of agricultural chemistry, and must be a matter of surprise, occurring as it does among the members of an association organized solely for the purpose of testing and perfecting analytical methods. The papers of the different reporters show that a comparatively small proportion of the members take part in the study of the various methods. As a consequence, new and worthless methods are likely to be adopted unadvisedly, or the adoption of desirable methods unnecessarily delayed. The latter is more likely to be the case, owing to a recent amendment to the constitution, which prevents the precipitate adoption of new methods or ill-considered modifications of old, well-proven methods. its work is so much to be desired, it is equally important that more While more active coöperation of all members of the Association in individual effort be directed toward devising and perfecting necessary laid before it at its recent convention, well tested in all of its details, a methods in certain lines. As a result of such effort the Association had volumetric method for determining phosphoric acid which effects a great saving in time and expense and which is probably fully the equal of present standard methods in accuracy. The investigations of an individual chemist also pointed out a probable source of serious error in the methods for determining potash, and indicated the means of avoiding it. Such work redounds not only to the credit of the individual performing it, but, what is probably of greater importance, it demonstrates the vitality and effectiveness of the Association. For the first time in the history of the Association a thorough editing and revision of its methods was provided for. It is extremely unfor tunate that adequate provision has not been made from the beginning for putting into the best possible form the methods of analysis adopted by over nine-tenths of the official chemists of this country in actual practice and accepted by the rest of the scientific world as the finished product of the leading agricultural chemists of the United States. In the appointment of the abstract committee of the Association the number was increased to nine members. The committee consists of Messrs. E. W. Allen, J. L. Beeson, W. D. Bigelow, B. W. Kilgore, W. H. Krug, C. L. Parsons, H. J. Patterson, A. M. Peter, and F. W. Woll. This committee is charged with the preparation of abstracts and lists of papers appearing in current periodicals on analytical methods and apparatus for fertilizers, feeding stuffs, dairy products, soils, sugar, fermented and distilled liquors, and tannin, this representing the pres ent scope of the Association. The work of this committee should be one of the most useful features of the Association in providing a means for keeping abreast with the work on methods in the several lines. In order to bring the abstracts more promptly to the notice of members of the Association, their periodical publication in the Record was commenced last year. The work of the committee for 1895-'96 has been organized and the publication of its abstracts will begin in the next number of the Record. In view of the increase in the number of abstractors it is hoped that the work of this committee will be even more profitable than heretofore. CONVENTION OF ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS, 1895 The twelfth annual convention of the Association of Official Agricultural Chemists was held in the lecture room of the National Museum at Washington, D. C., September 5-7, H. A. Huston presiding. Seventy chemists were in attendance. A committee consisting of R. C. Kedzie and W. C. Stubbs was appointed to wait upon the Secretary and Assistant Secretary of Agriculture and invite them to take part in the proceedings of the convention. The Secretary appeared before the convention and delivered a short address, in which he called attention to the need of educating the farmer to meet the intense competition in the markets of the world and spoke of the value of the various agricultural institutions for this purpose. A brief address was also delivered before the Association by ex-Assistant Secretary Willits. The president, in his annual address, pointed out the desirability of fuller discussion of papers presented before the Association, and advised some action by the convention with reference to amendment or interpretation of the portions of the constitution relating to the sending out of samples, reagents, and report blanks by reporters; the choice of a place of meeting; and changes in methods. He also proposed that descriptions accompany samples of fertilizers sent out by the different reporters, and called attention to the need of methods for distinguishing between available phosphoric acid of superphos phates and non-acidulated materials, and of investigation of methods of analysis of human foods. The following committee on recommendations of reporters was appointed: J. B. Lindsey, H. J. Wheeler, H. J. Patterson, A. M. Peter, and B. B. Ross. Fertilizers.-(1) Potash.-The report on potash was submitted by H. J. Wheeler, and summarized the results of studies by 11 analysts, including 1 Norwegian chemist, of the influence of the presence of different impurities (tricalcium phosphate, sulphuric acid, magnesium chlorid, and cane sugar) upon the accuracy of present official methods; and of the sources of error in these methods pointed out by N. Robinson' and Breyer and Schweitzer.2 The results indicate the reliability, under proper manipulation, of both the Lindo-Gladding and alternate methods for the purposes of fertilizer analysis, even in presence of large amounts of impurities. A. L. Winton described 2 classes of crystals of potassio-platinic chlorid-one comprising pulverulent compound crystals, the other Jour. Amer. Chem. Soc., 16 (1894), No. 6, p. 364 (E. S. R., 6, p. 105). 263 granular octohedral crystals. He found that while the latter were completely dried without special difficulty at the temperature of boiling water, the former required continued heating at elevated temperatures sometimes as high as 160° C. He had further observed that the smaller crystals were usually formed in abundance when the solu tion of the potash salt, to which the platinic chlorid was added, was sufficiently concentrated to give an immediate precipitate. On the other hand, when the solution was so dilute that no immediate precip itation occurred, the larger crystals usually predominated in the salt obtained. He recommended investigations with reference to the establishment of a new factor for calculating potash from the potassioplatinic chlorid. The principal changes in the methods for potash consisted in inserting directions in the proper places for diluting the final solution of potassium chlorid so that no immediate precipitate will appear on the addition of platinic chlorid; for washing the potassio-platinic chlorid with 80 per cent alcohol (by volume); and for drying the salt finally obtained at over 100° C. The subject of the change of factor was referred to the reporters for next year. (2) Phosphoric acid.-B. W. Kilgore reported the results of tests by 14 analysts, including 1 Norwegian chemist, of the molybdic and citrate methods of determining phosphoric acid. A large amount of data was presented which tended to confirm the substantial accuracy of the molybdic method, but was inconclusive as to the citrate method. The reporter also gave results of tests of the volumetric method of Pemberton, modified by himself, which indicated that this method is both rapid and accurate and may probably be adopted with advantage as an official method. The results obtained by this method were as a rule lower than those obtained with the official molybdic method, but the indications were that they were nearer the truth than the results by the latter method. In the discussion which followed the reading of this report, H. A. Huston called attention to the importance of having complete data regarding the composition of samples of phosphate distributed by the reporter to the various analysts. H. J. Wheeler suggested that discrepancies in the results obtained by different analysts in the determination of insoluble phosphoric acid might be explained by changes which go on in samples of phosphate on standing, and that probably the results would be more concordant if the determinations of soluble and reverted phosphoric acid could all be made on the same date. A paper on the citrate method of phosphoric acid determination, with special reference to insoluble phosphates, was presented by F. Bergami. The author stated that while the citrate method in the extremely simple form used for the tests reported will not give absolutely correct results, "still as long as it can be proven that with 1 Jour. Amer. Chem. Soc., 17 (1895), No. 6, p. 453 (E. S. R., 7, p. 88). |