CONVENTION OF ASSOCIATION OF OFFICIAL AGRICULTURAL 



CHEMISTS, 1896. 



W. H. Beal, 



Office of Experiment Stations. 



The thirteentli annual convention of the Association of Official Agri- 

 cultural Chemists was held in the lecture room of the National Museum 

 at Washington, D. C, I^ovember 6, 7, and 9, B. B. Koss presiding. 

 About 50 ir^embers were in attendance. 



A committee consisting of W. Frear and J. B. Lindsey was ap- 

 pointed to wait upon the Secretary and Assistant Secretary of Agri- 

 culture and invite them to attend the meetings of the Association. The 

 Assistant Secretary responded to this invitation and made a brief 

 address commending the work of the Associatiou. 



The president's annual address was devoted principally to a review 

 of recent i)rogress in the methods of analysis of fertilizers, especially 

 those relating to the determination of total and citrate-soluble phos- 

 phoric acid. It was pointed out that the official method for the deter- 

 mination of citrate-soluble phosphoric acid is not reliable on all kinds 

 of fertilizing materials. A review of the literature relating to tests of 

 other methods indicate that these methods give equally unsatisfactory 

 results. The advantage to be derived from the publication of afficial 

 methods in foreign languages as provided for at the International Con- 

 gress at Paris was briefly discussed. Attention was called to the exten- 

 sive dissemination of fraudulent formulas for home-mixed fertilizers, 

 and the desirability of the Association giving more attention to the 

 nature and adulteration of human foods was urged. Conservatism in 

 the matter of changing methods was insisted upon. 



The usual committee on recommendations of reporters was appointed 

 as follows: H. J. Wheeler, B. W. Kilgore, L. L. Yan Slyke, R. H. 

 Gaines, and H. A. Huston. 



Fertilizers. — (1) Phosphoric acid. — H. B. McDonnell presented a 

 report on phosjioric acid, giving a summary of (1) determinations of 

 total phosphoric acid by 15 chemists with the official gravimetric, volu- 

 metric, modified volumetric, Gladding, and citrate (Glaser's and modi- 

 fied GlavSer's) methods in 3 samples of fertilizers containing from about 

 11.5 to 28 x)er cent of phosphoric acid, and (2) determinations of soluble 

 and insoluble phosphoric acid by 10 chemists in 2 of the samples. 

 While the results are not entirely concordant, they indicate that the 

 present official method is reliable. Difficulty from the solubility of the 

 precipitate obtained by the volumetric method as modified by Kilgore 

 was reported. 



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