VI 
PREFACE. 
sheets the reader will perceive that the manner in which I was 
obliged to travel, prevented me from prosecuting my researches 
so far as I could have wished. In order to furnish results 
which I could not myself present, I gave to M. Brongniart, 
of the Academy of Sciences, the specimens of minerals which 
I brought back with me, requesting him to determine their 
nature. This service he performed forme, and commissioned 
M. Berthier, Professor of the School of Mines, to analyse the 
iron ores. Thus, owing to the kindness of these two gentle- 
men, to whom I take this public opportunity of expressing my 
gratitude, accurate notions may be formed respecting the 
mineralogy of the mountainous tracts bordering upon the 
sources of the Senegal and of the Gambia. M. Eyries has also 
done me the favour to subjoin to my work some geographical 
remarks on my discoveries. 
I have, perhaps, shown some courage in confronting, 
young as I still am, the dangers to which I was incessantly 
exposed by the restless sus]:)icion of the Negroes, or the almost 
invariably fatal effects of an intensely hot climate : this is 
the only title on which I shall found a claim to the indulgence 
of those who may peruse my narrative. Age and experience 
have not yet matured the observations which it contains, nor 
given to my style all the polish that might be desired ; but, at 
any rate, I have not attempted to embellish or to disguise 
such facts as relate to myself at the expense of truth. The 
reader will not therefore find in my travels any of those 
