393 



It appears from the experiments cited that seawater cannot 

 be regarded as saturated with alkali and that it will take up 

 more if brought into contact with a suitable bottom ^). 



How much it will take up we do not know, however, with 

 any accuracy, and in order to ascertain this a series of experi- 

 ments ought to be made on the lines initiated by Dittmar, but 

 connected with accurate determinations of tension and tempe- 

 rature. Such experiments will be very easy to perform by means 

 of my method of tension-determination, and I would take up 

 the problem myself if I did not fear that the abnormal alkalinity 

 of my present stock of seawater would vitiate the results. As 

 it is 1 must leave it to other investigators who may be in a 

 position of more easily obtaining the necessary supplies of pure 

 ocean-water. 



It appears with certainty from Dittmars determinations of 

 alkalinities in the ocean that bottom-waters are, as a rule, 

 more strongly alkaline than surface-waters and waters from 

 intermediate depths_, but the exceptions to this rule are rather 

 numerous. When the experiments above referred to have been 

 made it will, in all probability, be possible to explain some of 

 these exceptions and to learn something about the influence of 

 the bottom upon the alkalinity by a comparative study of the 

 alkalinities and the chemical composition of the corresponding 

 bottom-samples. 



From tlie tables of the Ingolf-Expedition I have extracted 

 the following figures for the alkalinities at depths about 1000 

 Danish fathoms or more. The first series of stations (47 — 67) 

 comprises the deep sea south of Iceland and east of the high 

 barrier «Reykjanæs-Ryg» stretching in a south-westerly direction 

 from the SW-point of Iceland. In all the samples of bottom- 

 water from this tract a very high alkalinity is found. The 



^) The remarkable fact that calcareous deposits do not exist at the greatest 

 depths of the ocean (beyond 2800 fathoms) points to the same conclusion 

 {Challenger, Narrative, vol. 1 p. 920—926). 



