Issued April 19, 1911. 
U.S. DEPARTMENT OF AGRICULTURE, 
BUREAU OF CHEMISTRY — BULLETIN No. 136. 
H. W. WILEY, Chief of Bureau. 
SHELLFISH CONTAMINATION FROM SEWAGE- 
POLLUTED WATERS AND FROM 
OTHER SOURCES. 
By 
GEORGE WHITFIELD STILES, Jr., 
In Charge, Bacteriological-Chemical, Investigations. 
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GOVERNMENT PRINTING OFFICE. 
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