_Mademoiselle:_ The French word for miss, a young girl.

_Magnesia:_ A light and white alkaline earth, which enters into the composition of many rocks, communicating to them a greasy or soapy feeling and a striped texture, with sometimes a greenish color.

_Malaria:_ (Italian, _mal/aria, bad air_,) a noxious vapor or exhalation; a state of the atmosphere or soil, or both, which, in certain regions and in warm weather, produces fever, sometimes of great violence.

_Mammon:_ Riches, the Syrian G.o.d of riches. See Luke 16:11-13; St.

Matthew 6:24. _Mexico:_ A country situated south-west 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 p.r.o.nunciation 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, etc., caused by moisture.

_Militate:_ To oppose, to operate against.

_Millinet:_ A coa.r.s.e kind of stiff muslin, formerly used for the foundation or basis of bonnets, etc.

_Mineralogy:_ A science which treats of the inorganic natural substances found upon or in the earth, such as earths, salts, metals, etc., and which are called by the general name of minerals.

_Minutiae:_ The smallest particulars.

_Monasticism:_ Monastic life; religiously recluse life in a monastery or house of religious retirement.

_Montagu, Lady Mary Wortley:_ One of the most celebrated among the female literary characters of England. She was daughter of Evelyn, Duke of Kingston, and was born about 1690, at Th.o.r.esby, in England She displayed uncommon abilities at a very early age, and was educated by the best masters in the English, Latin, Greek, and French languages.

She accompanied her husband (Edward Wortley Montagu) on an emba.s.sy to Constantinople, and her correspondence with her friends was published and much admired. She introduced the practice of inoculation for the small-pox into England, which proved of great benefit to millions. She died at the age of seventy-two, A.D. 1762.

_Moral Philosophy:_ The science which treats of the motives and rules of human actions, and of the ends to which they ought to be directed.

_Moreen: A kind of woolen stuff used for curtains, covers of cushions, bed hangings, etc.

_Mortise: A cavity cut into a piece of timber to receive the end of another piece called the _Tenon_.

_Mucous:_ Having the nature of _mucus, a glutinous, sticky, thready, transparent fluid, of a salt savor, produced by different membranes of the body, and serving to protect the membranes and other internal parts against the action of the air, food, etc. The fluid of the mouth and nose is mucus.

_Mucous membrane: That membrane which lines the mouth, nose, intestines, and other open cavities of the body.

_Muriatic acid: An acid composed of chlorine and hydrogen, called also, hydrochloric acid and spirit of salt.

_Mush-stick:_ A stick to use in stirring _mush, which is corn-meal boiled in water.

_Nankeen_ or _Nankin:_ A light cotton cloth, originally brought from Nankin, in China, whence its name.

_Nash, (Richard:)_ Commonly called _Beau Nash, or King of Bath, a celebrated leader of the fashions in England. He was born at Swansea, in South-Wales, October 8th, 1674, and died in the city of Bath, (England,) February 3d, 1761.

_Natural History:_ The history of animals, plants, and minerals.

_Natural Philosophy:_ The science which treats of the powers of nature, the properties of natural bodies, and their action one upon another. It is sometimes called _physics_.

_New-milch cow:_ A cow which has recently calved.

_Newton, (Sir Isaac:)_ An eminent English philosopher and mathematician, who was born on Christmas day, 1642, and died March. 20th, 1727. He was much distinguished for his very important discoveries in Optics and other branches of Natural Philosophy. See the first volume of _Pursuit of Knowledge under Difficulties_, forming the fourteenth volume of _The School Library_, larger series.

_Night-Soil:_ Human excrement, so-called because usually removed from privies by night.

_Non-bearers:_ Plants which bear no flowers nor fruit.

_Northern States_: Those of the United States situated in the northern and eastern part of the country.

_Ordinary_: See _Physician in ordinary_.

_Oil of Vitriol_: (sulphuric acid, or vitriolic acid,) an acid composed of oxygen and sulphur.

_Oino-mania_: A disease of the brain produced by excessive use of alcoholic stimulants; derived from two Greek words, _oinos_, wine, and _mania_, madness. The same disease sometimes arises from overuse of tobacco and other stimulants of the nerves.

_Orleans, (Elizabeth Charlotte de Baviere) d.u.c.h.ess of_: Second wife of Philippe, the brother of Louis XIV., was born at Heidelberg, May 26th, 1652, and died at the palace of St. Cloud, in Paris, December 8th, 1722.

She was author of several works; among which were _Memoirs and Anecdotes of the Court of Louis XIV._

_Ottoman_: A kind of ha.s.sock or thick mat for kneeling upon; so-called from being used by the Ottomans or Turks.

_Oxalic acid_: a vegetable acid, which exists in sorrel.

_Oxide_: A compound of a substance with oxygen, though not enough oxygen to produce an acid; for example, oxide of iron, or rust of metals.

_Oxidize_: To combine oxygen with a body without producing acidity.

_Oxygen_: The vital element of air, a simple and very important substance which exists in the atmosphere and supports the breathing of animals and the burning of combustibles. It was called oxygen from two Greek words, signifying to produce acid, from its power of giving acidity to many compounds in which it predominates.

_Oxygenized_: Combined with oxygen.

_Pancreas_: A gland within the abdomen just below and behind the stomach, and providing a fluid to a.s.sist digestion. In animals, it is called the sweet-bread.

_Pancreatic_: Belonging to the pancreas.

_Parterre_: A level division of ground, a flower-garden.

_Pearlash_: The common name for impure carbonate of potash, which in a purer form is called _Saleratus_.

_Peristaltic_: Contracting in successive circles; worm-like.

_Petroleum_: Rock oil, an inflammable, bituminous liquid exuding from rocks or from the earth in the neighborhood of the carboniferous or coal-bearing formation.

_Phosphorous_: One of the elementary substances.