IIORTON — GEOLOGY OF THE STONESFIELD SLATE. 
249 
Let us in conclusion examine the nature of the waters whicli now 
impregnate the great mass of lower palseozoic strata in Canada. 
According to Mr. Hunt in them " only about one-half the chlorine is 
combined with the sodium (common salt), the remainder exists as 
chlorides of calcium and magnesium, the former predominating, while 
the sulphates are present only in small amounts." 
Comparing the composition of these waters, which may be regarded 
as representing that of the ancient palaeozoic sea, with our modern 
ocean, we find, as we have ah-eady theoretically inferred, that the 
chloride of calcium (lime) has been replaced by common salt (chlo- 
ride of sodium), a process involving the presence of carbonate of soda 
and the formation of carbonate of lime. 
Let us now finally return to our question. Was the sea always 
salt ? If what we have deduced be correct, we may answer that the 
first ocean was one highly charged with various salts, chiefly chlo- 
rides of calcium and magnesia ; that, with the continued action of 
atmospheric waters bringing down carbonate of soda to the sea, a 
chemical process has been constantly carried on, by which the 
chlorides of calcium and magnesia have been gradually but con- 
tinuously diminished, and the quantity of chloride of sodium, or 
common salt, proportionately increased, and consequently that the 
saltness of the sea is greater now than in its ancient state, and has 
been constantly increasing from the remotest times unto our own. 
ON THE GEOLOGY OF THE STONESFIELD SLATE AND 
ITS ASSOCIATE FORMATIONS. 
BY Wll.LlAM S. HORTON, OF LIVERPOOL. 
There are, perhaps, few spots richer in the " time-hallowed memo- 
ries of the past" than the old town of Woodstock, near Oxford. In 
its immediate neighbourhood once stood a royal palace, where, as the 
readers of Scott will doubtless remember, many of the scenes in one 
of his novels are laid. The site of this ancient fabric is now occu- 
pied by the more stately pile of Blenheim, the princely residence of 
the Duke of Marlborough. In the park there is a spring still termed, 
in allusion to the legend more or less familiar to all students of Eng- 
VOL. III. 2 I 
