"... with the aim to apply it as a painter, as well as in my quality of entomologist .. .. what parts, provinces or regions of our country 'least' visited from an entomological point of view ..?"

“..at least I have the conviction of being honest and I do despise most of all those.. ..alienating works of art , the disease of our time.”

“..and then it remains you to re-create your study, the fragment, into a painting. For remember; these are two things: Nature is the material from which we must take. But don't be fooled by the modern theories, that imitating, copying nature would be 'everything'. The goal, the Art's aim is .... to move..”

“I certainly believe that the simple landscape which seems less impressive is the nature that is most proper to paint.”

“There is still some study here for the Dutch landscape, and I believe the best I can do is to stay some time longer.”

“I repainted the only unsold picture that was in Rotterdam last year. It seems to me that it looks quite pleasing and good now.. .I want you to ask him seven hundred guilders.. ..for six hundred as lowest price I would be willing to sell it and if you think - knowing him - it would be better to ask that price at once, so do it.”

“is in spite of all its difficulties, and perhaps because she has given so much trouble, less fresh and has become a little heavy - I myself have considered for a long time whether she was good enough to send it”