1. This was letter 845.
2. A letter written by Dr Peyron to Theo on 29 January 1890 reveals that Vincent had had another attack two days after his trip to Arles. His visit to Arles had taken place on 18 or 19 January (see letter 841, n. 1), so he must have suffered the attack on 20 or 21 January. On the 29th he was still in bad shape, as emerges from Peyron’s letter: ‘He is incapable at present of any kind of work, and only responds with incoherent words when asked questions’ (Aujourd’hui, il est incapable de se livrer à un travail quelconque et ne répond que par des paroles incohérentes aux questions qu’on lui adresse) (see FR b1061; Hulsker 1971, p. 41).
3. In the above-mentioned letter Peyron had confirmed, on Vincent’s behalf, the receipt of this letter (letter 843 of 22 January).
4. This was letter 844.