Aug. 1 1925 
Colloidal Silica and Efficiency of Phosphates 
259 
LITERATURE CITED 
(1) Association of Official Agricultural Chemists. 
1920. OFFICIAL AND TENTATIVE METHODS OF ANALYSIS. AS COMPILED 
BY THE COMMITTEE ON REVISION OF METHODS. REVISED TO 
November 1, 1919. 417 p., illus. Washington, D. C. 
(2) Burgess, P. S., and Pember, F. R. 
1923. “active "aluminum as a factor detrimental to crop production 
in many acid soils. R. I. Agr. Exp. Sta. Bui. 194, 40 p., illus. 
(3) Conner, S D. 
1924. some factors affecting the growth of crops on acid soils. 
Indus, and Engin. Chem. 16: 173-175. 
(4) Gedroits, K. (Gedroiz, K.) 
1911. AUF welchen boden wirkt der phosphorit. die mit basen 
gesattigten und ungesattigten boden. Russ. Jour. Exp. 
Landw. 12: 529-546. [In Russian, German r6sum6, p. 539-546.] 
(5) Gile, P. L., and Carrero, J. O. 
1915. ash composition of upland rice at various stages of growth. 
Jour. Agr. Research 5: 357-364. 
(6) -and Carrero, J. O. 
1916. assimilation of iron by rice from certain nutrient solu¬ 
tions. Jour. Agr. Research 7: 503-528. 
(7) -and Carrero, J. O. 
1916. a plan for testing efficiencies of fertilizers. Jour. Amer. 
Soc. Agron. 8: 247-255, illus. 
(8) - and Carrero, J. O. 
1923. efficiencies of phosphatic fertilizers as affected by liming 
AND BY THE LENGTH OF TIME THE PHOSPHATES REMAINED IN 
porto rican soils. Jour. Agr. Research 25: 171-194, illus. 
(9) Glixelli, S. 
1923. influence des sels neutres sur les gels de silice. Compt. 
Rend. Acad. Sci. [Paris] 176: 1714-1716. 
(10) Gordon, N. E., and Starkey, E. B. 
1922. influence of soil colloids on availability of salts. Soil 
Sci. 14: 1-7, illus. 
(11) Gr^goire, A. 
1911. l'ACTION SUR LES VEGETAUX SUPlSRIEURS DE QUELQUES SELS 
HYDROLYSABLES ET DE QUELQUES COLLOIDES. Bui. Soc. Chim. 
Belg. 25: 85-103. 
(12) Hall, A. D., and Morison, C. G. T. 
1906. ON THE FUNCTION OF SILICA IN THE NUTRITION OF CEREALS. 
i. Proc. Roy. Soc. London (B) 77: 455-477, illus. 
(13) Hall, T. D., and Vogel, J. C. 
1923. reversion of acid phosphate in acid soils. Soil Sci. 15: 367-369. 
(14) Hoffmann, M. 
1921. zur frage des phosphatdunger-problems. Centbl. Agr. Chem. 
50: 370-372. 
(15) Jennings, J). S. 
1919. THE EFFECT OF CERTAIN COLLOIDAL SUBSTANCES ON THE GROWTH 
OF WHEAT SEEDLINGS. Soil Sci. 71 201-215. 
(16) JODIN, V. 
1883. du r6le de la silice dans la v^g^tation du mais. Ann. Chim. 
et Phys. (V) 30: 485-494. 
(17) Kellner, O., and Bottcher, O. 
1900-01. untersuchungen uber die dungerwirkung der knochen- 
mehlphosphorsaure. Deut. Landw. Presse 27: 665-666, 
1900; 28: 194^195, 204, 1901, illus. 
(18) Knop, W. 
1861-62. QUANTITATIV-ANALYTISCHE ARBEITEN UBER DEN ERNAHRUNGS- 
process der pflanzen. Landw. Vers. Stat. 3: 295-324, 
1861; 4: 173-185, 1862. 
(19) Kreuzhage, C., and Wolff, E. 
1884. BEDEUTUNG DER KIESELSAURE FUR DIE ENTWICKLUNG DER 
haferpflanze. Landw. Vers. Stat. 30: 161-197. 
(20) Lemmermann, O., and Wiessmann, H. 
1922. DIE ERTRAGSSTEIGERNDE WIRKUNG DER KIESELSAURE BEI UN- 
ZUREICHENDER phosphorsaureernahrung der pflanzen. 
Ztschr. Pflanzenernahr. u. Dungung. (Wiss. Teil) (A) 1: 
185-255, illus. 
