I just discovered this etching of a drawing by the Eighteenth Century Italian caricaturist Piero Leone Ghezzi (1674 – 1755). This was included in 24 Raccolta Caricature disegnato by Piero Leone Ghezzi, Dresden 1750.
The original is on the left, but as some of the writing is reversed through the etching, I have mirrored this on the right.
Apparently the figure is Ghezzi himself. He was rather satirical in his caricatures and often rather cruel, so it seems he chooses to depict himself as distilling vitriol from his head.
There were a number of satirical images from the 18th century using alchemical references. I immediately recall some of the drawing by Rowlandson.