452 Transactions. — Chemistry. 



ammonia, showing very clearly tliat these saline solutions are more powerful 

 solvents in this respect when used cold. 



The exact quantity of calcic carbonate which a solution of any one of 

 these salts of a certain strength can dissolve has not yet heen ascertained, 

 but the results of experiment No. 3 show a certain minimum capacity of 

 sodic chloride in this respect. Thus it appeared by it that the highly 

 calcareous Oamaru water, when charged with sodic chloride at the rate of 

 one pound per gallon, does not afford any calcareous precipitate when sub- 

 mitted to Clarke's process. Now the total quantity of calcareous precipitate 

 afforded me by this process as applied to the water in its normal state was 

 no less than 21-75 grains to the gallon. Clearly then this quantity of 

 calcareous matter (calcic carbonate) is retained by this water in a soluble 

 form, showing a certain minimum cajyacity of the sodic chloride in this 

 respect, a computation which may, however, be found to fall far short of 

 that which represents its actual capacity when this shall be properly tested. 



In conclusion, I would submit to you that these results show : — 



1st. That Clarke's softening process cannot be advantageously applied 

 to hard water containing alkaline salts in quantity unusually large for such 

 waters. 



2nd. That sea- water, containing as it does a very large quantity of these 

 salts, has a considerable solvent power upon every limestone formation with 

 which it is in contact; a fact which should, I conceive, be taken into account 

 by geologists in connection with the erosion of these rocks by sea- water. 



3rd. That the actual quantity of calcic carbonate present in one gallon 

 of average sea-water may be considerably more than that which is now 

 customarily assigned to it — viz., three grains to the gallon, as this quantity 

 is merely got by a computation in which the solveiK-y of the compound in 

 jiure water is taken as a guide ; it is obvious, however, that an addition 

 should be made to this, so that the quantity dissolved by the salts of 

 this water may be included in the estimate. 



Art. LXVIII. — On the Degree of Solubility of certain Earthy Carbonates in 

 pure Water. By W. Skey, Analyst to the Geological Survey Depart- 

 ment. 



[Read before the Wellington Philosophical Society, 12th January, 1878.] 

 The degree to which certain earthy carbonates are held to be soluble in 

 pure water by those chemists who have studied this matter, is so variously 

 and so divergently stated by them that, practically, we cannot rightly 



