So, it seemed sensible to try dipping the brass into alum or potassium nitric solutions instead of sulphuric and nitric acids, as suggested by JDP, in a recipe taken from Della Porta’s “Natural Magic”. The setup was the same as before, a strip of modern brass sheet, probably a bit high in Zinc compared to historical brass, heated by a blowtorch and quenched into solutions.
Here it is before:
Admire the shininess of the brass, with the small scratches probably imparted during the rolling process to turn bar into sheet.
After I dipped it into alum and potassium nitric solutions, I did find it somewhat whitened. The problem was I did this a couple of weeks ago when I was suffering from bad sinuses and disturbed sleep, so I forgot to write down which solution produced this result, because I was actually going to write it up then not now, but anyway.
So this time round it does work a bit better, exactly how I have no idea, I’ll have to go and think about it.
There are quite a few more recipes in della Porta, although some are a bit toxic.
I am also working on the bigger alchemy book, which means I might be doing experiments, just not ones I want to put up online, or else what’s the point of the book? Asking you all to contribute to my expenses isn’t going to make me rich, the only way to go is mass media exposure or actually turning lead into gold, which I know isn’t possible, leaving me with the book and whatever else I can get from it.