4 points
*
https://www.marxists.org/archive/marx/works/1864/letters/index.htm
Its quoted everywhere, but I think its in here as I found the date to be 1864, unforutnatly it seems copyright stricken.
Its a letter to ‘Lion Philip’ - 1864
I will keep looking for a proper source.
2 points
3 points
*
It is on page 186-187 of this book, which has all the letters of Marx
“From letter to Lion Philips (in Zalt-Bommel) London, June 25, 1864”