What is "mersalyl"

n. An organomercury compound.

Mersalyl (Mersal) is an organomercury compound ( mercurial diuretic). It is only rarely used as a drug, having been superseded by diuretic medications that do not contain mercury and are therefore less toxic. It features a Hg(II) centre. Mersalyl was originally adapted from calomel (HgCl), a diuretic discovered by Paracelsus.