[...] Yesterday I parted finally with Liszt—who has been with me over six weeks—accompanying him as far as the Bodensee. We have got through a lot together, but our intercourse would have been yet more productive had it not been for illness on one side and the awful professorial mania of the Princess on the other, which caused some emotional disturbance. Whatever the lady is, however (a monstrum per excessum in soul and heart anyhow), one cannot be angry with her for long; only it takes Liszt's incomparable temperament to endure all this vivacity. I, poor devil, suffered very much from it at times—I cannot support this everlasting excitement. So now I can scarcely feel anything but gladness at getting peace again and being able to think of resuming work. Liszt's new compositions have completely captured me. The asses—and that is what most of them are—will have a job of it to dispose of this phenomenon. It is perfectly obvious to me, even where I am least in sympathy with him, and I am absolutely satisfied as to the eminent value of his creations. At St. Gall, where they got up a kind of music festival for us, he performed his Orpheus and the Préludes for me, the former of which I consider a quite unique masterpiece of the utmost perfection. And the Préludes, too, in which I could wish for a little more originality in the chief motives, are beautiful, bold and noble. [...]
Source: Letters of Richard Wagner, Vol. 1, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 318