355 



measured, together with the corresponding quantities of carbonic 

 acid, and if, further, the physical absorption of carbonic acid 

 in the water is exactly known, it ought to be possible to ascer- 

 tain by calculation, on the basis of the known laws of chemical 

 mass-action, the real nature of the alkaline substances in sea- 

 water and the combination of carbonic acid with them. I have 

 therefore resumed the problem and made several series of 

 experiments with a « standard »-seawater from the North- 

 Atlantic, viz. 



1. An experimental determination of the physical absorp- 

 tion of carbonic acid at different temperatures. 



2. A series of determinations of the total quantities of 

 carbonic acid together with the corresponding tensions at a 

 constant temperature. 



3. Determinations of the variations of the tension with 

 the temperature, while the quantity of carbonic acid remained 

 unaltered. 



1. The coefficient of absorption of carbonic acid was 

 determined in water that was sligthly acidulated by means of 

 a few drops of muriatic acid (20 %). This slight alteration of 

 the concentration has no perceptible influence upon the absorp- 

 tion, but it neutralizes the alkalinity and prevents the binding 

 of COg by dissociation of some of the «insignificant» components 

 of seawater. 



The acidulated water was completely saturated with carbonic 

 acid at the barometric pressure obtaining and at a known 

 temperature, which was kept scrupulously constant during each 

 determination. The quantity absorbed was determined by evacua- 

 tion of 15 — 23 grms. of the water in the mercury-pump and 

 subsequent analysis. For the reduction of the quantities of 

 water weighed to cubic-centimeters, at the temperature of the 

 experiment, 1 utilized Dittmars determinations [Challenger Reports^ 

 Physics and Chemistry vol. 1, p. 74). 



23* 



