 Travelers during the colonial period of Mexico frequently mention mezcal, usually with an admonition as to its potency.Alexander von Humboldt mentions it in his Political Treatise on the Kingdom of New Spain (1803), noting that a very strong version of mezcal was being manufactured clandestinely in the districts of Valladolid (Morelia), Mexico State, Durango and Nuevo León.He mistakenly observed that mezcal was obtained by distilling pulque, contributing to its myth and mystique.