CONVENTION OF OFFICIAL AGRICULTURAL CHEMISTS. 505 



desiral)ility of clettM'iniiiing- and reporting upon the forms of nitrogen 

 in the analysis of commercial fertilizers. 



The Jones and Street methods for nitrogen were recommended for 

 further trial at the hands of the referee for next season. 



Phoxplior'te acid. — The report was presented by the referee, E. G. 

 Runyan. Results were reported from 19 analysts on the samples sent 

 out for determination of the total phosphoric acid b}- the official gravi- 

 metric method, optional v'olumetric method, and volumetric by shak- 

 ing at room temperature. In 16 reports the several methods agreed 

 fairly well, and may be considered quite satisfactory. 



Results on the determination of iron and alumina in phosphates were 

 reported by T analysts. These were rather discordant, although agree- 

 ing more closely than the previous year. While the results reported 

 on the determination of iron by the permanganate method do not agree 

 very well, the referee believes this to be the best means for determin- 

 ing iron in phosphates. The results of tests of the acetate and the 

 phenylhydrazin methods of alumina determination do not warrant the 

 drawing of definite conclusions, but the referee lielieves that some form 

 of the acetate method will prove to be the better. 



H. J. Wheeler presented a paper upon Increased accuracy in phos- 

 phoric acid determination. In this he asked the special attention of 

 the Association to the work of Gooch and Austin (E. S. R.. 11, p. 107), 

 and suggested certain modifications of the official method of determin- 

 ing phosphoric acid. By the proposed modification close approxima- 

 tions to theoretical results are obtained, and the laboratory is freed 

 from the strong odor of ammonia and the expense materiall}' reduced. 



P. MacFarland read a paper on basic slag, in which he reviewed 

 the sale of this material in Canada and the trials of the official chemists 

 in the Dominion in establishing a proper valuation of the soluble phos- 

 phate content. He presented the results of certain modifications in 

 the methods of analysis of this product, and asked the cooperation of 

 the Association in the further study of the question. After some dis- 

 cussion the question of the adoption provisionally of the 2 per cent 

 citric acid solution method of Wagner and the consideration of the 

 paper presented Avas referred to the referee for another year. 



C. B. Williams described Kilgore's modification of the volumetric 

 method of estimating phosphoric acid. By this method 30 phosphoric 

 acid samples xn^y be analyzed with ease daily. From a large number 

 of comparative tests with the gravimetric method the results were in 

 all cases reported as extremely satisfactory. 



SOILS. 



The report on soils by the referee, B. L. Hartwell, covered the past 

 2 years. At the meeting in 1898 the Association reconmiended work 

 upon the so-called international method of determining assimilable 



