If air bubbles are noticed in the capillary 

 part of the cup, remove them by means of a 

 wire. Introduce the Hg and acid into the 

 reaction chamber by carefully opening the 

 connecting cock and lowering the leveling 

 bulb. Reseal the cup capillary with a few 

 drops of Hg. 



5. Lower leveling bulb until mercury 

 is at the 50 ml. mark and then shake sample 

 for 3 minutes. 



6. Allow the Hg level to rise until 

 the liquid is exactly on the 2 ml. mark. 

 Record manometer reading. 



7. Add 0.2 ml. of 5N NaOH to the cup 

 over the Hg seal. Making sure there are no 

 bubles in the capillary, introduce the NaOH 

 into the reaction chamber. Reseal cup with 

 a few drops of Hg. 



8. Lower the Hg level to about 25 ml. 

 and shake the sample for 1 minute. After 

 shaking, place the leveling bulb in exactly 

 the same position as in item 7 and allow 

 liquid to again ascend to the 2 ml. mark. 



9. Record the manometer reading. 



10. From the manometer readings and 

 the ambient temperature, compute the quan- 

 tity of CO2 in the sample analyzed from the 

 following equation (Van Slyke and Neill 

 1924): 



^°'760 V 760 (l+0.00384t 



where V* , , 



X'^A') 



,^,^ = volume of CO-j measured 

 760 "^ 



under standard conditions; 



P = partial pressure of CO2 — i.e., 

 difference in manometer readings; 



a = volume of the gas at which P is 

 measured; 



i = reabsorption coefficiait of the 

 gas in the liquid in the reaction chamber; 



t = temperature at which the manometer 

 readings are made; 



S = collective volume of sample and 

 reagents; 



A = capacity of the extraction cham- 

 ber; 



a' = the distribution coefficient of 

 CO2 of sea water are supplied in table 1. 



Table 1. --Factors for calculating CO2 content of sea water. 



(When A= 50 ml. , S = 11 ml . , a= 2 ml . , and sample =10 ml . ) 



Temp. 

 °C 



15 

 16 

 17 

 18 

 19 

 20 

 21 

 22 

 23 

 24 

 25 

 26 

 27 

 28 

 29 

 30 



