Cocaine was brought to Europe after the discovery of America. In the 19th century, the active component of coca leaves, named cocaine, was extracted and several researchers started experimenting with the substance, describing many physiological and pathological effects of its action. The first scholar to practically demonstrate the possibility of using cocaine solution in medicine, mostly ophthalmology, was Carl Koller. Following this remarkable achievement cocaine became the substance most frequently applied for different types of anaesthesia. Halsted and Hall reported the first successful nerve block of the interior dental nerve with 4% cocaine solution. In 1892, Schleich published the results of his studies in which he used a 0.1–0.2% solution of cocaine hydrochloride intra- and subcutaneously, introducing the so-called infiltration anaesthesia. At the end of the 19th century it was, however, demonstrated that cocaine possessed many undesirable effects, including addiction, which triggered off interest in other, less toxic, anaesthetics.