Dear Theo,

I just received your letter and the enclosure, for which many thanks. I want to answer you at once that I often met with sayings of Diderot's, and that I too think that he fits well into the framework of his time. It's the same with him as with Voltaire himself, when one reads a letter of those men's, even on the most commonplace things, or about nothing, there is a brightness and a sparkling spirit in them which charm. Let's not forget that they were the men who made the Revolution, and that it is the work of a genius to dominate one's time, and to make the minds that are thoughtless and passive strive in one direction and after one aim. So I have all respect for them. Shortly you will receive two studies of the autumn leaves, one in yellow - poplars - the other in orange - oaks.

I am completely absorbed in the laws of colours. If only they had taught us them in our youth!

But it is the fate of most people that by a kind of fatality one has to seek for light a long time. For, that the laws of colour which Delacroix was the first to use, like Newton did for gravitation, and like Stephenson did for steam - that those laws of colours are a ray of light - is absolutely certain.

I have made another autumn study of the pond in the garden at home. There decidedly is a picture in that spot. I already tried to get it last year.

The one I made now is a rather stiff composition - to the right, two trees - orange and yellow; in the centre, two bushes of grey-green; to the left, two trees of brownish-yellow. In front of them the black pond - a foreground of withered grass. The background - a glimpse over the hedge on a very vivid green. A sky of slate-grey and dark blue to harmonize with this in strength.

I am sure they will find it too black and too dark, but the time of making dark studies is always too short.

I enclose the book by Ch. Blanc in the box with the studies, also a Bible which those at home gave me for you, of which I painted a still life.

Don't let it trouble you when in my studies I just leave the brush strokes as I put them on, with smaller or larger clots of paint. That doesn't matter at all; if one leaves them for a year (or half a year is enough), and then scrapes them off quickly with a razor, one gets a much more solid colour than would be the case after painting thinly. And this scraping off has been done by the old masters as well as by the French painters of today. I believe that glacis of a transparent colour often gets quite dark and disappears in time if they are applied before the picture in its preparation is thoroughly dry; but applied later, they will certainly keep. You yourself made the observation that my studies in the studio became better rather than worse in colour in the course of time. I think this comes from laying the colours on thickly, and not using oil. When it is a year old, the little oil which the paint always contains has evaporated, and the healthy solid part remains. This question - that of painting so that it keeps - is rather important, I think; it is a pity that some durable colours like cobalt are so expensive.

I do not know what to think of the chromates and dark carmines, but I can quite understand that especially the American sunsets - you know those kinds of paintings that are obtained by glacis of chromates only - last an exceedingly short time. Daubigny and Dupré, on the contrary, will keep. Isn't it curious that that Van der Meer of Delft in The Hague has kept colour so splendidly, with that whole series of glaring tones of red, green, grey, brown, blue, black, yellow, white?

Haverman's picture in Amsterdam, which I suppose you remember (as not good), is badly painted, terribly badly, considering the time, I fear. I just mention this because he especially is so much admired for his technique. But it is painted as well, I should say, as for instance Ary Scheffer painted, or like the technique of Delaroche - and lovers of healthy vigorous work have always had some objections to those two. I noticed in Fodor how those pictures that are smoothed with oil crack terribly. Yet Silvestre says that Delacroix bathed his pictures in oil “les baignait d'huile”; but I suppose that it was strongly empâté work, first treated en pleine pâte, then left for a year, and then afterward Delacroix drenched those pictures with oil, after they were dry to the core. Then it can do no harm.

Goodbye,

Ever yours, Vincent

Has there been no Lhermitte this month? I am longing for de Goncourt.