376 



Pub. Piigct Sound Biol. Sta. 



Vol. 2, No. 54 



5. Hydrogen-ion concentration and oxygen content of surface 

 sea-water, and their relation to tide 

 The hydrogen-ion concentration and in most cases the oxygen content 

 of the surface sea-water at stations Q, D and A were taken at intervals 

 thruout the course of the investigation (see tables 3, i and 5, and map 

 on page 372). When these tables are examined to determine the relation 

 cf the pH and oxygen content of the surface water to the stage of the tide 

 there seems to be no general conformity. On July 23, 1919, the pH 



Table 3. The hydrogen-ion concentration and the oocygen content 

 of the surface sea-water at station Q. 



Table 4. The hydrogen-ion concentration and the oxygen content 

 of the surface sea-mater at a depth of 10 centimeters at station D. 



