AUTHOR’S PREFACE.
I now offer to the public the second edition of a book whose success has far surpassed my expectations. Received with kindness by some, it has been violently attacked by others. It was denounced to the highest representatives of the university authority on which I depended, and I owed my escape from the trouble which might have been drawn on me,—because I brought forward a scientific opinion in disagreement with the books attributed to the prophet Moses,—to the justice of one of the most honoured members of the Institute. I owe a large debt of gratitude to my illustrious protector. The mind has advanced during six years, and the same troubles will not be met with again.
A good many alterations will be discovered in this Second Edition; this is always the case with science. In matters of imagination, when the artist has finished his work, he can cast it on the world and follow his fancy in some other way. If science were only composed of truths, its conditions would almost be the same for its disciples; but the seeker after truth is not a creator like an artist, he explains and reflects upon a world of facts, variable at every hour, according as hypotheses are changed into certainties, or certainties of yesterday into doubtful cases of to-day. It is, then, an incessant work of reparation and alteration, in order to maintain even the most modest work in harmony with the daily progress of science; I have made this work as perfect as was in my power. I have taken great care with the list of authorities. I have also indicated by their titles all the articles from periodicals, reviews, or academic collections, to which I refer the reader. I am sure that those who know what an ungrateful task it is to search such badly catalogued libraries as most of ours are, will give me credit for this part of my work. We can only see the expression of science at a given moment in Mémoires. Books are, after all, merely a summary: they are behind-hand even on the day they are published.
G. P.