U. S. DEPARTMENT OF AGRICULTURE. 
BUREAU OF PLANT INDUSTRY—BULLETIN NO. 281. 
B. T. GALLOWAY, Chief of Bureau. 
ABSORPTION AND EXCRETION OF SALTS BY 
ROOTS, AS INFLUENCED BY CONCEN- | 
TRATION AND COMPOSITION OF 
CULTURE SOLUTIONS. 
I— CONCENTRATION RELATIONS OF DILUTE SOLUTIONS OF CALCIUM AND 
MAGNESIUM NITRATES TO PEA ROOTS. 
BY 
RODNEY H. TRUE, 
Physiologist in Charge, 
AND 
HARLEY HARRIS BARTLETT, 
Chemical Biologist, 
Drug-Plant, Poisonous-Plant, Physiological, and 
Fermentation Investigations. 
IssuED January 30, 1912. 
WASHINGTON: 
GOVERNMENT PRINTING OFFICE. 
1912. 
