I well remember that around 1874, Duret, who is above reproach, Duret himself said to me with all sorts of circumlocutions that I was on the wrong track, that everyone thought so, including my best friends... I admit that when alone, with nobody to prompt me, I reproached myself similarly, - I plumbed myself, - decision was terribly hard. - Should I, yes or no, persevere [or seek] another way? I concluded in the affirmative, I took into account the risks of the unknown, and I was right to stick.