As a five year old I encountered a picture of a young man in a rakish hat and a yellow coat, on the wall of a large classroom. There was something instantly intriguing about the image, but it was also puzzling because it represented neither politician nor prince, the usual fare for Australian school decorations. I was eventually told that this was a reproduction of a painting, the artist was Vincent van Gogh, and that the subject was some young Frenchman. On special days we assembled in that room and during the next several years I found myself gazing beyond visiting speakers at the fellow in the yellow jacket. It was almost another fifty years before I felt properly conversant with the portrait and realized that van Gogh's subject, Armand Roulin, was seventeen at the time ofthe original painting and had died at seventy-four during my schoolboy contemplations. In the interim my enjoyment of the works of the Impressionists and Post Impressionists had grown and I occasionally ran into the name of Dr. Gachet, Vincent's last attending physician, in books and catalog essays. The doctor was my entree to the overlapping charms of medical and art histories.In 1987 I had the good fortune to participate as a biochemist in the centenary celebration of the Pasteur Institut in Paris.