114 Journal of Agricultural Research voi. xviii. No. a 



LITERATURE CITED 

 .(i) Atkins, W. R. G. 



I916. SOME RECENT RESEARCHES IN PLANT PHYSIOLOGY. xi, 328 p., llluS. 



London, New York. Bibliography, p. 303-323. 



(2) BouYoucos, George J. 



1912. TRANSPIRATION OP WHEAT SEEDLINGS AS AFFECTED BY SOILS, BY SOLU- 



TIONS OP DIFFERENT DENSITIES, AND BY VARIOUS CHEMICAL COM- 

 POUNDS. In Proc. Amer. Soc. Agron., v. 3, 1911, p. 130-191, 16 fig. 

 Bibliography, p. 190-191. 



(3) and McCooL, M. M. 



1915. THE FREEZING-POINT METHOD AS A NEW MEANS OP MEASURING THE 



CONCENTRATION OF THE SOIL SOLUTION DIRECTLY IN THE SOIL. Mich. 



Agr. Exp. Sta. Tech. Bui. 24, 44 p., 2 fig. 

 (4) 



I918. DETERMINING THE ABSOLUTE SALT CONTENT OP SOILS BY MEANS OF TllE 



FREEZING-POINT METHOD. In Jour. Agr. Research, v. 15, no. 6, p. 331- 

 336. Literature cited, p. 336. 



(5) BrEnchlEy, Winifred E. 



1916. THE EFFECT OF THE CONCENTRATION OP THE NUTRIENT SOLUTION ON THE 



GROWTH OP BARLEY AND WHEAT IN WATER CULTURES. In Ann. Bot. , V. 



30, no. 117, p. 77-90. 



(6) BURD, J. S. 



1918. WATER E!XTRACTIONS OF SOILS AS CRITERIA OP THEIR CROP-PRODUCING 



POWER. In Jour. Agr. Research, v. 12, no. 6, p. 297-309, i fig. 



(7) 



1919. THE RATE OF ABSORPTION OF SOIL CONSTITUENTS AT SUCCESSIVE STAGES 



OP PLANT GROWTH. In Jour. Agr. Research, v. 18, no. 2, p. 51-72. 



(8) Clark, William Mansfield, and Lubs, Herbert A. 



1917. THE COLORIMETRIC DETERMINATION OF HYDROGEN-ION CONCENTRATION 



AND ITS APPLICATION IN BACTERIOLOGY. In Jour. Bact., V. 2, no. I, p. 



i-34> fig- 1-4; no. 2, p. 109-136, fig. 5-7; no. 3, p. 191-236, fig. 8-9. 

 References, p. 233-236. 



(9) Davidson, J., and LeClErc, J. A. 



1918. THE EFFECT OF SODIUM NITRATE APPLIED AT DIFFERENT STAGES OP GROWTH 



ON YIELD, COMPOSITION, AND QUALITY oP WHEAT. In Jour. Amer. 

 Soc. Agron., v. lo, no. 5, p. 193-198. 



(10) FiNDLAY, Alexander. 



1913. OSMOTIC PRESSURE. 84 p., 2 fig. London, New York. 



(11) GainEY, p. L. 



1918. SOIL REACTION AND GROWTH OF AZOTOBACTER. In Jour. Agr. Research, 

 V. 14, no. 7, p. 265-271. 



(12) GiLE, P. L., and Carrero, J. O. 



1916. assimilation of iron by rice from CERTAIN NUTRIENT SOLUTIONS. In 



Jour. Agr. Research, v. 7, no. 12, p. 503-528. 



(13) Gillespie, L. J. 



1916. THE reaction op soil AND MEASUREMENTS OP HYDROGEN-ION CONCEN- 

 TRATION. In Jour. Wash. Acad. Sci., v. 6, no. i, p. 7-16, 2 fig. 

 C14) and Hurst, Lewis A. 



1918. HYDROGEN-ION CONCENTRATION — SOIL TYPE — COMMON POTATO SCAB. In 



Soil Sci., V. 6, no. 3, p. 219-236, 3 fig. References, p. 235-236. 

 (15) Hall, Alfred Daniel, and Underwood, Lilian Marion. 



X913. THE SOIL solution and THE MINERAL CONSTITUENTS OP THE SOIL. III. 

 THE RATE OF DIFFUSION OP THE NUTRIENTS IN THE SOIL SOLUTION. In 



Phil. Trans. Roy. Soc. London, s. B., v. 204, p. 194-198. 



