[35] Vid. op. cit. supra, p. 173.

[36] Comptes rendus, Tome 54, p. 468.

[37] Crookes’ Select Methods, p. 500.

[38] For details of method see Fresenius quantitative Analysis.

[39] U. S. Department of Agriculture, Chemical Division, Bulletin 43, p. 341.

[40] Letter to B. W. Kilgore, Reporter for Phosphoric Acid to the Association of Official Agricultural Chemists.

[41] Die Landwirtschaftlichen Versuchs-Stationen, Band 38, S. 304.

[42] Communicated by Dr. Solberg.

[43] From the Official Swedish Methods; translated for the author by F. W. Woll.

[44] Methoden van Onderzock aan de Rijkslandbouw-proefstations, 1893, p. 4.