INTRODUCTORY LETTER. 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 Egyptian Commission. We 

 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 knowTi the productions of a countr}^, 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 vdtli 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 w^e 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 1 



I think it necessary to say a few words on the choice of 

 the French language in the composition of my book. 

 The motives Mhich 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 



