1836.] BAHIA, BRAZIL. 495 
From the absence of all carbonaceous matter, Professor Ehren- 
berg believes that these organic bodies have passed through the 
volcanic fire, and have been erupted in the state in which we 
now see them. The appearance of the layers induced me to 
believe that they had been deposited under water, though from 
the extreme dryness of the climate I was forced to imagine, that 
torrents of rain had probably fallen during some great eruption, 
and that thus a temporary lake had been formed, into which the 
ashes fell. But it may now be suspected that the lake was not a 
temporary one. Anyhow, we may feel:sure, that at some former 
epoch, the climate and productions of Ascension were very dif- 
ferent from what they now are. Where on the face of the earth 
can we find a spot, on which close investigation will not discover 
signs of that endless cycle of change, to which this earth has 
been, is, and will be subjected ? 
On leaving Ascension we sailed for Bahia, on the coast of 
Brazil, in order to complete the chronometrical measurement of 
the world. We arrived there on August Ist, and stayed four 
days, during which I took several long walks. I was glad to 
find my enjoyment in tropical scenery had not decreased from the 
want of novelty, even in the slightest degree. The elements of 
the scenery are so simple, that they are worth mentioning, as a 
proof on what trifling circumstances exquisite natural beauty 
depends. 
The country may be described as a level plain of about three 
hundred feet in elevation, which in all parts has been worn into 
flat-bottomed valleys. This structure is remarkable in a granitic 
land, but is nearly universal in all those softer formations of 
which plains are usually composed. The whole surface is covered 
by various kinds of stately trees, interspersed with patches of 
cultivated ground, out of which houses, convents, and chapels 
arise. It must be remembered that within the tropics, the wild 
luxuriance of nature is not lost even in the vicinity of large 
cities; for the natural vegetation of the hedges and hill-sides 
overpowers in picturesque effect the artificial labour of man. 
Hence, there are only a few spots where the bright red soil 
affords a strong contrast with the universal clothing of green. 
From the edges of the plain there are distant views either of 
the ocean, or of the great Bay with its low-wooded shores, and 
22 
e 
