INTEODUCTOEY LETTEE. 
11 
countries, I have been able to find useful notices only in 
the works of the Prince of Neuwied, of Spix, of Russel, 
and in that published by the Eg3rptian Commission. W e 
possess, it is true, works, already quoted, that embrace a 
description of the serpents of certain places ; but besides 
that these works are very few, they are drawn up for the 
most part in a manner little conformable to the actual 
state of the science. Some of them offer simply an enu- 
meration of species characterized by a short phrase, or at 
best are merely a compilation of existing works on ophi- 
ology. To make known the productions of a country, it 
is, in the first place, necessary to amass an ample collec- 
tion of them, composed of individuals of every age and 
sex. In disposing of those numerous materials, without 
troubling one’s self about what has been done before, we 
arrive at a knowledge of the species under all their rela- 
tions. Before writing the descriptions, it is necessary to 
compare the species with their congeners, natives of other 
countries. And, in consulting works already existing, we 
shall then be enabled easily to unravel the synonymes, and 
to reject the reduplication of descriptions. It is true, that 
the composition of such a work is a labour at least of se- 
veral years, especially when we wish to add notices on the 
manners and habits — a circumstance, as it appears to me, 
of prime importance ; but should a philosopher take into 
his consideration the time, when the question regards the 
utility to science ? 
I think it necessary to say a few words on the choice of 
the French language in the composition of my book. 
The motives which have induced me to this choice are 
simple, and easy to be guessed ; therefore I should have 
passed over in silence this subject, if grave accusations had 
not been raised against some of my countrymen, who have 
acted as I have done. In our days, when all the world 
is in search of instruction, when the sciences have every- 
where acquired popularity, and have so many enlightened 
amateurs, the man of the world, or well-informed, though 
not learned persons, to whom the Latin is not familiar, 
have contributed to the progress of the sciences ; assured- 
ly, in these fortunate times, it would be unseasonable to 
