138 . ACCOUNT OP THE 



of this formation, they are not found ; but this should be attri- 

 buted to the influence of climate. The ice to which they were 

 attached could not of course pass a certain latitude ; and from 

 the great increase of these masses as we advance towards the 

 north, it would seem that many of the ice-bergs suffered 

 dissolution long before they arrived at this maximum. Fu- 

 ture observers will no doubt trace them to their parent stra- 

 ta in the arctic regions, as Von Buck has traced those which 

 are lodged on the shores of the, Baltic. 1 he ice islands of 

 the Atlantic ocean may reasonably be supposed to bring 

 down, and deposit on its bed in the Temperate Zone, pri- 

 mordial masses, similar to those spread over some parts of 

 this and the European continent. These islands are, I be- 

 lieve, not often seen further south than the forty-first de- 

 gree, near two degrees north of their southern boundary 

 here. This is probably attributable to the gulf stream ; but 

 for which, the larger tracts of ice would undoubtedly attain 

 as low a latitude as the southern limits of the primitive blocks 

 in this country : and hence a probable conclusion may be 

 drawn, that the temperature of the northern hemisphere 

 has undergone but little change since the remote epoch when 

 this part of the continent was for the last time subjected to 

 inundation. 



i shall, Sir, no longer employ you with my premature, 

 and, 1 fear, abortive attempts at generalising some of the 

 geological phenomena of this country. I have, indeed, oc- 

 cupied too much of your time in tlie discussion of points 

 with which perhaps you were already better acquainted 

 than myself. 



I have drawn liberally on your patience, because the 

 kindness which you have shown me at various times has in- 

 spired a hope, that you will excuse both the tediousness and 

 temerity of my speculations. However this may be, 1 trust 



