U. S. DEPARTMENT OF COMMERCE 
Daniel C. Roper, Secretary 
BUREAU OF FISHERIES 
Frank T. Bell, Commissioner 
DETECTION AND MEASUREMENT 
OF STREAM POLLUTION 
By M. M. ELLIS 
From BULLETIN OF THE BUREAU OF FISHERIES 
Volume XLVIII 
Bulletin No. 22 
UNITED STATES 
GOVERNMENT PRINTING OFFICE 
WASHINGTON : 1937 
For sale by the Superintendent of Documents. Washington, D. C. 
Price 20 cents 
