Mr. Mornay's account of the discovery 
stratified, but they consist of loose sandy materials, except in 
so far as they contain beds of a dark red iron ore, containing 
imbedded minute crystals of magnetic iron ore: the thick- 
ness of these beds is about two inches, and they are exactly 
similar to those which are found in the clay hills of Bahia. 
The smaller hillocks consist of confused heaps of gravel 
and loose stones, intermixed with a very large quantity of the 
same iron ore in fragments, and lumps of manganese, very 
compact, and of a steel grey colour, containing arsenic, but 
apparently no iron. 
The dreary appearance of this plain is increased by the 
numerous nests of cupim, (white ants,) standing upright like so 
many tombstones. On being viewed nearer, they are conical, 
rather compressed, so that the base is elliptic. All those 
which I examined were precisely of the same shape. The 
materials of which they consist are white sand, whitish clay, 
and particles of wood. 
Many of them were full five feet in height. 
The soil of the valleys and low grounds, which are occa- 
sionally swampy, is abundantly impregnated with sea salt, 
which the inhabitants wash out for their own consumption ; 
but it contains some bitter salts, which render it purgative to 
tho$e who are not accustomed to it. 
The thermal springs which were pointed out to me, were 
several, but they hardly deserve the name. 
One of them was at 86° of Fahrenheit when the atmos- 
phere was at 8 1°. 
Another was at 88°, when the atmosphere was at 77^° ; 
and also at 88° when the atmosphere was at 8o°. 
The water of both of these is the purest I had ever seen. 
