I found it to be a fascinating account of the authors investigation into the life of Van Gogh; where he lived and painted, his family, his physical and emotional health and the doctors that treated him and Theo. (I used this book as a source in my first post, "Isolation")
There are no formal photographs of Van Gogh as a mature man, in spite of the fact that photography as we know it had been developing, so to speak, since the 1840's.
This photo was found, luckily by an artist who must have jumped on it, in an antique dealers shop in Massachusetts, bought for $1, and taken for forensic image comparisons. It eventually was evaluated at the H.C.Lee Institute of Forensic Science, University of New Haven, and the conclusion was "in all probability, this is a rare photo of Vincent Van Gogh as an adult". The Van Gogh Museum in Amsterdam doesn't agree, but museums don't like their apple carts upset.(my opinion) Van Gogh painted between thirty and forty self-portraits. I've taken some and reversed them for easier comparison to the photo. The last image is a painting of Van Gogh done by an Australian compatriot, John Russell.
Vincent Van Gogh by John Russell