At the end of the XVI century, a pupil of Parcelsus, the chemist Oswald Crollio, proposed the theory of the signs: according to that, the shape or colour of a plant, which remind of a particular part of the body, can be used to treat that specific organ (for example Pulmonaria officinalis against pulmonary illnesses, and Hepatica Nobilis for the liver). Other examples of chemists in the XVI century are Z. Bovio and F. Calzolari, both from Verona: the former showed up "acqua regia" (KNO₃ + H₂SO₄ + NaCl which distilled melts gold) and a miraculous medicine against the temperature and infermities, called "Miraculous Hercules". The latter perfected the composition of the Theriarca, the antidote-polymedicine against snakes bite. From latter experiences of alchemy were born the iatrochemy, today’ s pharmacology, and chemestry, our phisiology.