Mesopotamia.
Mestizoes.
Meta, river: plains of the.
Meteorology, main problem of.
Meteors: connection of, with the undulations of the earth. falling. fiery, seen at Cumana. luminous.
Mexico, or New Spain: connection of, with foreign colonies. native population of. state of society in. nobility of. wheat of. government of. agriculture of. extent of.
Miasma, experiments on.
Mica-slate, formations of.
Middleberg.
Migration: of nations. of insects. of plants. difficulties of the theory.