Don't give up! There are lots of wonderful old formulas out there that were abandoned or not adequately researched. I would certainly do the experiments however, I do not have the knowledge and experience with chemistry. I wanted to try Stieglitz's platinum toning formula but I thought 'nitric' sounded much too close to 'nitro'.... Well if anyone achieves some success with Pt toning please let us know. Hmmmmmm........ Plazo.........