Alkaloid use of Ephedra and opium poppies. Also, coca leaves have been used by South American Indians since ancient times. Extracts from plants containing toxic alkaloids, such as aconitine and tubocurarine, were used since antiquity for poisoning arrows. Studies of alkaloids began in the 19th century. In 1804, the German chemist Friedrich Sertürner isolated from opium a "soporific principle" (), which he called "morphium" in honor of Morpheus, the Greek god of dreams; in German and some other Central-European languages, this is still the name of the drug. The term "morphine", used in English and French, was given by the French
Church of the Holy Mother of God, Asen's Fortress of God, this may well not have been its actual name. The dedication is alleged based on a partial Medieval Greek inscription in the church, which may have been a donor's inscription. In the early 20th century, the part of the inscription that was still visible was deciphered as "ή παναγία τῆς Πετριζηώτης", equivalent to "or the Mother of God of Petrich". However, this was the name of the main church ("katholikon") of the nearby Bachkovo Monastery, which makes it more likely that the inscription references the monastery and its relation to the church in Asen's Fortress in some way,