Just stumbled across Vincent van Gogh: The Letters project, an extensive archive of the letters and sketches Van Gogh wrote throughout his life, commissioned by The Van Gogh Museum in Amsterdam. I took quite some time scrolling through this. I wish more like this existed out there in the world. It's fascinating and goes quite well with the book I bought at the Strand recently, The World's Greatest Letters.
In a letter from Vincent Van Gogh to Paul Gauguin dated 17, June 1890
(2 years after a "frustrated and ill, Van Gogh confronted Gauguin with a razor blade. In panic, Van Gogh left their hotel and fled to a local brothel. While there, he cut off the lower part of his left ear lobe. He wrapped the severed tissue in newspaper and gave to a prostitute named Rachel, asking her to "keep this object carefully."- 23, December 1888)
A few translated excerpts -
"Thanks for writing to me again, my dear friend, and be assured that since my return I’ve thought about you every day. I only stayed in Paris for three days, and as the Parisian noise made a pretty bad impression on me I judged it wise for my head to clear off to the countryside – otherwise I would have swiftly run round to your place."
"we’ll try to do something deliberate and serious, as it would probably have become if we’d been able to continue down there. Look, an idea which will perhaps suit you. I’m trying to do studies of wheat like this, however I can’t draw it. Nothing but ears, blue-green stems, long leaves like ribbons, green and pink by reflection, yellowing ears lightly bordered with pale pink due to the dusty flowering."
The two artists never actually saw each other again after the incident with the blade in 1888, but apparently they kept in touch (though kept their distance).