CONVENTION OF OFFICIAL AGRICULTURAL CHEMISTS. 409 



and calcium and ammonium chlorids; 1 (5) humus and humus nitrogen 

 and, (6) incidentally, moisture and acidity. Four samples of soil of 

 known history were used, 2 from Rothamsted and 2 from Pennsylvania 

 Station. One soil from each place had been treated for a number of 

 years with pbosphatic fertilizers, while one had been cropped without 

 application of sucb fertilizers. 



Complete analyses by 4 chemists of the ash of fornilla wood (Prosopis 

 pubescens) are also reported. 



The results by the £ normal hydrochloric acid method agreed with 

 the known facts regarding the soils, but exaggerated the difference 

 between the phosphoric acid contents of the two Rothamsted soils. 

 While the ratio of the phosphoric acid content of the soil cropped 

 without phosphate to that of the soil receiving pbosphatic fertilizers, 

 as calculated from the known history of the system of manuring and 

 cropping pursued, was 1: 1.7, the treatment with £ normal acid showed 

 a ratio of 1: 11.7. 



The reporter for next year was instructed to make a further study 

 of the methods of digesting soil in calcium and ammonium chlorids and 

 £ normal hydrochloric acid. A committee consisting of M. A. Scovell, 

 A. M. Peter, and H. W. Wiley was appointed to revise the phraseology 

 of methods for soils and ash along the lines suggested by the reporter. 



H. J. Wheeler briefly reported the results of a study of the relation 

 between lime and humus in soil. He pointed out that the official 

 methods for examining soils furnish no indication of the real need of 

 lime in soils. Free and total humus were greatest in soils needing lime. 



H. A. Huston suggested that the digestion of soils in alkaline solu- 

 tions should be studied. 



The secretary presented a paper by E. W. Hilgard on the aims and 

 objects of soil analysis. In this paper the author insisted that nitro- 

 gen, phosphoric acid, and potash are not the only elements which 

 should be determined in analysis of soils. It is fully as important to 

 determine lime, ferrous salts, soluble silica, etc. He recommends the 

 use of dilute hydrochloric acid for determining available potash and 

 phosphoric acid. 



FOODS AND FEEDING STUFFS. 



A report on this subject, presented by J. B. Lindsey, was devoted to 

 the following subjects: (1) A comparison by 7 analysts of the diastase, 2 

 Maercker, 2 and salicylic acid (or modified Baudry 3 ) methods of deter - 



'U. S. Dept. Agr., Division of Chemistry Bui. 49, pp. 88, 91. 



2 U. S. Dept. Agr., Division of Chemistry Bui. 49, pp. 47, 48. 



3 Jahresber. Agr. Chem., 1892, p. 664. The modification used was as follows : Free 3 

 to 5 gm. of the substance from fat and water-soluble material. Bring the dried and 

 pulverized residue into a beaker with 200 cc. of water in which is dissolved % gm. 

 salicylic acid, and heat the beaker in a boiling-water bath, with constant stirring 

 until the starch is rendered soluble (10 to 15 minutes). Now filter quickly through 

 linen, using suction, wash with hot water to a volume of 200 cc. Add 20 cc. of 25 

 per cent hydrochloric acid and proceed as usual. 



