1. Quinine wine (vin de quinquina) is a medicinal wine prepared from the bark of the cinchona tree. The drink has an invigorating and antipyretic (fever-reducing) effect.

2. This painting was possibly Van Gogh’s chair (F 498 / JH 1635 ), which he mentioned working on in letter 736, or Blue gloves and a basket of oranges and lemons (F 502 / JH 1664 ), which he had just finished when he wrote letter 741.

3. Andries Bonger and Anne (Annie) Marie Louise van der Linden had been officially engaged since May 1886; their marriage took place on 3 May 1888 in Amsterdam. See Brief happiness 1999, p. 21.

4. Jo van Gogh-Bonger had written to Vincent on 15 January. See Brief happiness 1999, p. 90.

5. Van Gogh is mistaken about the sex: Guillaumin’s child, born on 14 October 1888, was a daughter, called Madeleine.

6. Van Gogh had asked Milliet if he would take charge of Bernard in Africa, if the latter went to serve with the Zouaves. See letter 628. Apparently no answer from Bernard was forthcoming.

7. Van Gogh compared Roulin to Socrates a number of times; see letter 652, n. 7. The passage on Socrates and the Parthenon is an allusion to Michelet’s L’amour; see letter 368, n. 4.

8. Alexandre Chatrian, of the writers’ duo Erckmann-Chatrian. Theo had told Vincent about his meeting with the author (see letter 723).

9. This was letter 737.

10. According to Van Gogh, Gauguin was thinking of settling in Brussels and travelling from there to Denmark to see his family. See letter 723.

11. For Gauguin’s The Schuffenecker family , see letter 737, n. 8.

12. Vincent had asked Theo to buy the engraving after Rembrandt’s Anatomy lesson for Dr Rey; see letter 732, n. 14.