1922] EATON—SULPHUR CONTENT OF SOILS 57 
4. No definite conclusions can be drawn from the data as to 
the relation of sulphur to chlorophyll development in plants. 
This may come about through the effect of the sulphur in increas- 
ing the nitrogen content of the plants. 
5. Flowers of sulphur and sodium sulphate, containing the same 
amount of sulphur as 100 pounds of gypsum per acre, and gypsum 
at rate of 500 pounds per acre, caused increased dry weights of 
sweet corn of 35-66 per cent. Larger amounts of flowers of 
sulphur and sodium sulphate gave no increases. The corn fertil- 
ized with sulphur had a higher moisture content than the controls. 
In the case of the gypsum series this amounted to 5 per cent. 
The writer wishes to acknowledge his indebtedness to Dr. 
WILLIAM CROCKER and Dr. SopHiA ECKERSON, under whose 
direction this investigation was conducted. A part of the investi- 
gation was conducted under a Research Fellowship from the 
Gypsum Industries Association. Thanks are due the Association 
for their kindness in furnishing the fellowship. 
UNIVERsIty oF CHICAGO’ 
LITERATURE CITED 
1. AMES, J. W., and Bortz, G. E., Sulphur in relation to soils and crops. 
Ohio Agric. Exp. Sta. Bull. 292. 221-256. 1916. 
2. Brown, P. E., and Kettoce, E. H., Sulphur and permanent soil fertility 
in Iowa. Jour. Amer. Soc. Agronomy 7:97-108. 1915. 
3- CARRIER, LyMAN, and co-workers, Alfalfa experiments. Va. Agric. Exp. 
Sta. Bull. 207. 1-20. 1914 
4. CROCKER, WILLIAM, History of the use of gypsum as a fertilizer (unpub- 
lished). 
5- Demoton, M. A., Sur 630 fertilisante du soufre. Compt. Rend. 
Acad. Sci. 154 3524-526. 
6. Dutey, F. L., Relation - slp to soil productivity. Jour. Amer. Soc. 
Agronomy 8: pes 19 
7. GRANTHAM, A. E., Alfalfa i in Delaware. Del. Agric. Exp. Sta. Bull. 110. 
I-42. 
8. Hart, E. B., and Pererson, W. H., Sulphur requirements of farm crops, 
in relation to the soil and air sipely. Wis. Agric. Exp - Sta. Research 
Bull. 14. 1-21. rorr. 
9- Hart, E. B., and Torrincuam, W. E., Relation. of sulphur compounds to 
plant nutrition. Jour. Agric. Res. 5 :233-250. 1915. 
