Mammon, riches, the Syrian god of riches. See St. Luke, xvi. 11, 13, St. Matthew, vi. 24.

Martineau, (Harriet,) a woman who has become somewhat celebrated by her book of travels in the United States, and by other works.

Mexico, a country situated southwest of the United States, and extending to the Pacific Ocean.

Miasms, such particles or atoms, as are supposed to arise from distempered, putrefying, or poisonous bodies.

Michilimackinac, or Mackinac, (now frequently corrupted into Mackinaw, which is the usual pronunciation of the name,) a military post in the State of Michigan, situated upon an island about nine miles in circuit, in the strait which connects Lakes Michigan and Huron. It is much resorted to by Indians and fur traders. The highest summit of the island is about three hundred feet above the lakes, and commands an extensive view of them.

Midsummer, with us, the time when the sun arrives at his greatest distance from the equator, or about the twenty-first of June, called, also, the summer solstice, (from the Latin sol, the sun, and sto, to stop or stand still,) because, when the sun reaches this point, he seems to stand still for some time, and then appears to retrace his steps. The days are then longer than at any other time.

Migrate, to remove from one place to another; to change residence.

Mildew, a disease of plants; a mould, spot, or stain, in paper, cloths, &c., caused by moisture.

Militate, to oppose, to operate against.