[...] I feel I must tell you that Cosima's reserve towards me has really grieved me, since I have felt certain that the language question is only a pretext and that as a matter of fact she does seriously feel disconcerted by me. If my manner has seemed peculiar to her, or if she has been hurt by a rough speech here and there or a touch of derision (of Herwegh and the like), I should very much regret having let myself go too far, in confident mood. This is a thing I am always heartily willing to admit and to bewail when I find I have alienated some person whom I really value. It is all a question of misunderstanding as I know very well. My reckless confidingness with people whom I find sympathetic has cost me many an estrangement. I hope that from your dear young wife may not be of long duration!
I have been in Paris two days, partly on business if you like, to sound a certain man personally who has offered to negotiate a possible French production of Tannhäuser and—in case of success—to secure me copyright in his opera. It was not urgent; but some external motive for a temporary absence from Zurich was not unwelcome to me. [...]
Source: Letters of Richard Wagner, Vol. 1, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 345