1888-89.] Mr Anderson on Solubility of Carbonate of Lime, 323 
Leaving only a difference of 1 centigramme per litre in favour 
of sea water. 
From this it appears to be a reasonable conclusion that the 
carbonate of lime present in sea water as such, is there simply owing 
to its solubility in the river water flowing into it, the salts present 
helping or retarding the solution as the case may he. 
It would seem, according to this view, that (except in special 
cases) the whole of the soluble carbonate of lime in sea water can 
be accounted for without the help of carbonic acid as a solvent, 
although, doubtless, its local action at great depths and in presence 
of decaying organic matter is notable. (See Reid’s paper, and Irvine 
and Young’s paper, Table II., Proceedings of Royal Society.) 
It will he seen by referring to the Table accompanying this paper 
that the amount of carbonate of lime dissolved by the various salts 
present in sea water amounts to 0T348; whilst the total amount 
of carbonate of lime figured as present in sea water, added to what 
it can yet dissolve, is 0T447, making the difference of 1 centigramme 
per litre in favour of sea water. The carbonic acid is therefore free 
to perform its true function, which is to support the enormous flora 
present in the ocean. Messrs Irvine and Woodhead, in their paper 
read before this Society, May 1888, indicate this as follows : — “ The 
relation between plant and animal life in the ocean is much the 
same as that between plant and animal life on land, so far as inter- 
change of carbon is concerned, considering the requirements of 
marine plant life in the form of carbon, which it can only obtain 
from the sea in the condition of carbonic acid.” 
The behaviour of a solution of carbonate of lime in sea water on 
standing in a closed vessel, where it is impossible carbonic acid 
could escape, seems to prove beyond question that its solubility 
has nothing to do with the existence of free carbonic acid or 
bicarbonates, as the major portion is thrown out of solution. 
Again, all the solutions of the various salts present in sea water, 
referred to in the Table, were made up according to the proportions 
in which they exist in sea water, with distilled water absolutely 
free from carbonic acid. 
[Table 
