Of all medical sciences in Slovenia, occupational medicine has the longest tradition. It is not a mere coincidence that it had developed already at the beginning of 18th century in Idria. The Mercury mine in Idria, is the second largest European mine of its kind, next to the Spanish Almaden, and has been owned by the Habsburg dynasty for four centuries. To attain higher production, the miners in Idria received medical and social care much earlier than anywhere else; chronic intoxication caused by mercury fumes greatly hindered their working ability. The first and, at the same time, one of the most prominent doctors in Idria, J.A. Scopoli (1723-1788) perfectly described the symptoms of chronic intoxication with mercury in his work De Hydrargyro Idriensi Tentamina Physico-Chymico-Medica (Venice, 1761) and thus ranked himself among the early medical writers of occupational medicine, medical hygiene and toxicology. His predecessors were Ellenbog, Paracelsus, Mattioli and some others. The article describes the situation in the mine of Idria in the 17th and 18th century and focusses on Scopoli's mineralogical and medical discussion on mercury miners and mercurialism.