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 O No. 4 6 

 © No. 47 (Control) 



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Figure 6. — Effects of 20 percent of crude oil extract on the rate 

 of water filtration of oysters. Extract of 200 ml, of crude oil 

 shaken for five hours in 4,000 ml, of sea water. Carmine cone 

 method. Arrow indicates time of addition. Plotting as in figures 

 3 and 4, 



