Wednesday, July 19:
R. had five hours of good sleep. He works. Never-ending sultriness; we suffer under it. In the evening I am very sad, I do not know whether because of an incident between R. and myself, in which he was perhaps too impassioned, I too reserved, or because of yesterday’s news, of which I am constantly thinking, particularly since this heat seems likely to be fatal for anyone with typhus.
In the afternoon R. corrects his biography; I read Semper’s pamphlet on science, industry, and art, which I find absorbing. In the evening, Frederick the Great.