1. See letter 687, n. 14, for the drawings Bernard sent. Van Gogh discusses the two sketches Prostitute, which are both on one side of a sheet. Brothel scene is on the back.

2. Van Gogh had written about the cost of living in Arles in his previous letter to Bernard (684).

3. A well-known saying that derives from the first aphorism of Hippocrates. It is known chiefly through Seneca, in the Latin translation: ‘Ars longa, vita brevis’ (De brevitate vitae, 1, 1).