424 NATURAL HISTORY OF AFRICA. 
It is much to be regretted, that those enter- 
prising men who have travelled in Africa have 
hitherto paid so little attention to natural history, 
and particularly to mineralogy. This latter branch 
of knowledge, however, is now so well understood, 
and so generally studied, that no traveller proceed- 
ing to that country will in future be considered as 
deserving the public confidence, or as accomplished 
for his purposes, without an accurate and scientific 
acquaintance with it. How much could Bruce, 
Browne, Park, and other distinguished travellers, 
have effected, had their knowledge of natural his- 
tory been more accurate and extensive ? 
The vast plains, numerous platforms, which are 
frequently indicated by the successive cascades in 
the course of the great rivers — and the vast ranges 
of mountains which characterize Africa in so strik- 
ing a manner, are intimately connected with the 
original formation of this continent, and also with 
those changes it has experienced in latter periods. 
These grand features in the physiognomy of this 
quarter of the globe, are not to be viewed as mere- 
ly accidental arrangements; on the contrary, it 
could be shewn, that all of them have a mutual and 
determinate relation to each other, and together 
form a grand whole, characteristic of Africa. 
Geognosy of Africa. 
Hitherto no extensive series of observations have 
