1. These were letters 866 and 868.
2. In his letter to Dr Gachet of 9 May, Theo referred to their meeting and informed him about Vincent. He said he hoped that Gachet would take his brother under his wing, and asked his opinion about having someone accompany Vincent during his railway journey. ‘He’s very well at the moment and writes me very sensible letters. He has a great wish to come to Paris for a few days and then to go and work in the country ... Do you think it would be prudent to have someone accompany him during the journey? He himself feels revulsion at having to be supervised and begs me to let him make the journey alone. I should very much like to have your opinion on the matter’ (Il est très bien en ce moment & m’écrit des lettres très raisonnables. Il a un grand désir de venir à Paris pour quelques jours & ensuite pour aller travailler à la campagne ... Croyez vous qu’il serait prudant de le faire accompagner par quelcun pendant le voyage. Lui même sent une répulsion à devoir être gardé & me supplie de lui laisser faire le voyage seul. J’aimerais beaucoup avoir vôtre avis la dessus) (FR b2014).
3. The Salon had opened on 1 May (see exhib. cat. Paris 1890-1).
4. This exhibition, held at the Ecole des Beaux-Arts and organized by Siegfried Bing, had 725 works on display. See Exposition de la gravure Japonaise à L’Ecole des Beaux-Arts à Paris du 25 avril au 22 mai. Catalogue. Paris 1890 and Correspondance Pissarro 1980-1991, vol. 2, p. 352 (n. 2). Theo saw the exhibition on 27 April (Account book 2002, p. 73).