Note 332 — PHARMACOLOGIA.
Reading edition
Or it may be detected, in very minute quantities, by the elegant test lately employed by Dr. Marcet, and which I have frequently repeated in my Lectures with considerable satisfaction. It consists in adding a little sulphuric acid with a small quantity of muriate of soda, and then immersing a little gold leaf in the mixture, when after boiling it, if any nitric acid should have been present, the gold leaf will be dissolved.