256 DEPTHS OF THE OCEAN chap. 



three hours it was found that the diatoms had consumed 

 2.34 cubic centi- 

 metres of the 

 oxygen in the dark '^• 

 bottle (the amount 

 of carbonic acid 

 being shghtly in- 

 creased), whereas 

 in the uncovered 

 bottle thequantity 

 of oxygen had 

 increased by i i.oo 

 c.c. (the amount of 

 carbonic acid 

 being decreased). 

 Brennecke has 

 compared the 

 results of a num- 

 ber of oxygen-de- 

 terminations from 

 the Atlantic 

 Ocean, and in 

 Figs. 173 and 

 174 his two sec- 

 tions showing the 

 vertical distribu- 

 tion of oxygen in 

 the Atlantic (from 

 the surface to a 

 depth of 1 500 

 metres) between 

 lat. 60° N. and 50 

 S. are reproduced. 

 The first section 

 shows the quan- 

 tity in cubic centi- 

 metres per litre. 

 A little north and 

 south of the equa- 

 tor the value is ^ 

 only 1-2 c.c. per 

 litre in the water 

 between 200 metres and 600 or 700 metres ; on the equator, 



