Cabbage tree. - Capital Adventures — LiveJournal
Many people seen to believe that photographic manipulation didn't start until the digital age and the creation of all the programs for doing so.
This proves not to be the case.
Man Ray 'stumbled' across a technique called both solarisation and Sabattier effect, in the 1930's. It was first described in 1859.
Jerry Ulesmann, among many others, creates composite photographs from multiple negatives, having as many as 6 to 8 enlargers in his darkroom. He started this long before the digital photography innovations came along.
Hmm. I wonder how that works. Do you have any references for the chemistry behind solarisation?