io6 . BOTANICAL GAZETTE [February 



LITERATURE CITED 



1. Ames, J. W., and Richmond, T. E., Fermentation of manure treated with 

 sulphur and sulphates. Changes in nitrogen and phosphorus content. 

 Soil Science 4 : 79-89. 1917. 



2. Effect of sulphofication and nitrification on rock phosphate. Soil 



Science 6:351-364. 1918. 



3. BouLLANGER, E., and DuGARDiN, M., Mechanisme de Taction du soufre. 

 Compt. Rend. Acad. Sci. Paris 155:327-329. 1912. 



4. Bradley, C. E., The reaction of lime and gypsum on some Oregon soils. 

 Jour. Ind. and Engin. Chem. 2:529-530. 1910. 



5. Brezeale, J.F., and Briggs, L.J., Concentration of potassium in ortho- 

 clase solutions not a measure of its availability to wheat seedlings. Jour. 

 Agric. Res. 20:615-621. 1921. 



6. Briggs, L. J., and Brezeale, J. F., Availability of potash in certain ortho- 

 clase bearing soils as affected by lime or gypsum. Jour. Agric* Res. 

 8:21-28. 1917. 



7. Brioux, Ch., and Guerbet, M., L'action fertilisante du soufre. Annales 

 Sci. Agron. 30:395-396. 1913- 



8. Brooks, W, P., Alfalfa. Mass. Agric. Exp. Sta. BuU. 154. 1914 (p. 158). 



9. , Phosphates in Massachusetts agriculture, importance, selection, 



and use. Mass. Agric. Exp. Sta. Bull. 162. 191 5. 



10. Brown, P. E., and Gwinn, A. R., Effect of sulphur and manure on avail- 

 ability of rock phosphate in soil. Iowa Agric. Exp. Sta. Res. Bull. 43: 



373-379- 1917. 



11. Brown, P. E., and Kellogg, E. H,, Sulphofication in soils. Iowa Agric. 

 Exp. Sta. Res. Bull. 18:104-110. 1914. 



12. Brown, P. E., and Warner, H. W., The production of available phosphorus 

 from rock phosphate by composting with sulphur and manure. Soil 

 Science 4:269-282, 1917. 



13. Browne, J. D., The field book of manures or the American muck book. 

 1854 (pp. 68-75). 



14. Bruckner, W. H., American manures. 1872 (p. 65). 



15. Crocker, Wm,, History of the use of gypsum as a fertilizer. (Unpub- 

 lished article.) 



16. Demolon, M. a., Recherches sur Taction fertilisante du soufre. Compt. 

 R.end. Acad. Sci. Paris 156:725-728. 1913. 



17. Duley, F. L., The relation of sulphur to soil productivity. Jour. Amer. 

 Soc. Agron. 8:154-160. 1916. 



18. Dymond, T. S., Hughes, F., and Jure, C. W. C, The influence of sulphates 

 as manures upon the yield and feeding value of crops. Jour. Agric. Sci. i : 

 217-229. 1905. 



19. Eaton, S. V., Sulphur content of soils and its relation to plant nutrition. 

 (Unpublished article.) 



