Well, he certainly made a good impression. (See, impression, like Impressionists, like impressionistic painting? Would have worked better if not for his being one of the Post Impressionists. Ah, well, it's late...)
A few years back this very web page mentioned something about a museum exhibition. Vincent van Gogh Pipe Smoking Exhibit in Amsterdam If you really want to know what he was smoking it can probably be found out. He seems to have enjoyed clay pipes and cherry wood pipes most but briar near the end of his short life.
I wonder what the guys smoked in them ... from what I read on his life he was quite a nut job. It may be due to funny stuff in his pipes and drink (absinthe back in those days was made by infusing real worm wood).