3. Vincent’s mention of the third part of
Cours de dessin actually refers to the second part,
Modèles d’après les maîtres de toutes les époques et de toutes les écoles; he took
Exercices au fusain to be the first part, even though it appeared independently. The second part of
Cours de dessin contains many portraits, the majority of which (at least 22) are after
Hans Holbein. The copy consulted by the Van Gogh Museum contains a total of
60 sample sheets (this series appeared from October 1868 to April 1870), but there must have been
67. Three drawings by Van Gogh after Holbein are known;
see letter 160, n. 12 and
letter 169.