Mercury \Mer"cu*ry\, n. [L. Mercurius; akin to merx wares.]

1. (Rom. Myth.) A Latin god of commerce and gain; -- treated by the poets as identical with the Greek Hermes, messenger of the gods, conductor of souls to the lower world, and god of eloquence.

2. (Chem.) A metallic element mostly obtained by reduction from cinnabar, one of its ores. It is a heavy, opaque, glistening liquid (commonly called quicksilver), and is used in barometers, thermometers, ect. Specific gravity 13.6. Symbol Hg (Hydrargyrum). Atomic weight 199.8. Mercury has a molecule which consists of only one atom. It was named by the alchemists after the god Mercury, and designated by his symbol, [mercury].

Note: Mercury forms alloys, called amalgams, with many metals, and is thus used in applying tin foil to the backs of mirrors, and in extracting gold and silver from their ores. It is poisonous, and is used in medicine in the free state as in blue pill, and in its compounds as calomel, corrosive sublimate, etc. It is the only metal which is liquid at ordinary temperatures, and it solidifies at about -39[deg] Centigrade to a soft, malleable, ductile metal.

3. (Astron.) One of the planets of the solar system, being the one nearest the sun, from which its mean distance is about 36,000,000 miles. Its period is 88 days, and its diameter 3,000 miles.

4. A carrier of tidings; a newsboy; a messenger; hence, also, a newspaper. --Sir J. Stephen. ``The monthly Mercuries.'' --Macaulay.

5. Sprightly or mercurial quality; spirit; mutability; fickleness. [Obs.]

He was so full of mercury that he could not fix long in any friendship, or to any design. --Bp. Burnet.

6. (Bot.) A plant (Mercurialis annua), of the Spurge family, the leaves of which are sometimes used for spinach, in Europe.

Note: The name is also applied, in the United States, to certain climbing plants, some of which are poisonous to the skin, esp. to the Rhus Toxicodendron, or poison ivy.

Dog's mercury (Bot.), Mercurialis perennis, a perennial plant differing from M. annua by having the leaves sessile.

English mercury (Bot.), a kind of goosefoot formerly used as a pot herb; -- called Good King Henry.

Horn mercury (Min.), a mineral chloride of mercury, having a semitranslucent, hornlike appearance.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Ivy \I"vy\, n.; pl. Ivies. [AS. [=i]fig; akin to OHG. ebawi, ebah, G. epheu.]

(Bot.) A plant of the genus Hedera (H. helix), common in Europe. Its leaves are evergreen, dark, smooth, shining, and mostly five-pointed; the flowers yellowish and small; the berries black or yellow. The stem clings to walls and trees by rootlike fibers.

Direct The clasping ivy where to climb. --Milton.

Ye myrtles brown, with ivy never sere. --Milton.

American ivy. (Bot.) See Virginia creeper.

English ivy (Bot.), a popular name in America for the ivy proper (Hedera helix).

German ivy (Bot.), a creeping plant, with smooth, succulent stems, and fleshy, light-green leaves; a species of Senecio (S. scandens).

Ground ivy. (Bot.) Gill (Nepeta Glechoma).

Ivy bush. (Bot.) See Mountain laurel, under Mountain.

Ivy owl (Zo["o]l.), the barn owl.

Ivy tod (Bot.), the ivy plant. --Tennyson.

Japanese ivy (Bot.), a climbing plant (Ampelopsis tricuspidata), closely related to the Virginia creeper.

Poison ivy (Bot.), an American woody creeper (Rhus Toxicodendron), with trifoliate leaves, and greenish-white berries. It is exceedingly poisonous to the touch for most persons.

To pipe in an ivy leaf, to console one's self as best one can. [Obs.]

--Chaucer.

West Indian ivy, a climbing plant of the genus Marcgravia.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Poison \Poi"son\, n. [F. poison, in Old French also, a potion, fr. L. potio a drink, draught, potion, a poisonous draught, fr. potare to drink. See Potable, and cf. Potion.]

1. Any agent which, when introduced into the animal organism, is capable of producing a morbid, noxious, or deadly effect upon it; as, morphine is a deadly poison; the poison of pestilential diseases.

2. That which taints or destroys moral purity or health; as, the poison of evil example; the poison of sin.

Poison ash. (Bot.)
   (a) A tree of the genus Amyris (A. balsamifera) found in the West Indies, from the trunk of which a black liquor distills, supposed to have poisonous qualities.
   (b) The poison sumac (Rhus venenata). [U. S.]

Poison dogwood (Bot.), poison sumac.

Poison fang (Zo["o]l.), one of the superior maxillary teeth of some species of serpents, which, besides having the cavity for the pulp, is either perforated or grooved by a longitudinal canal, at the lower end of which the duct of the poison gland terminates. See Illust. under Fang.

Poison gland (Biol.), a gland, in animals or plants, which secretes an acrid or venomous matter, that is conveyed along an organ capable of inflicting a wound.

Poison hemlock (Bot.), a poisonous umbelliferous plant (Conium maculatum). See Hemlock.

Poison ivy (Bot.), a poisonous climbing plant (Rhus Toxicodendron) of North America. It is common on stone walls and on the trunks of trees, and has trifoliate, rhombic-ovate, variously notched leaves. Many people are poisoned by it, if they touch the leaves. See Poison sumac. Called also poison oak, and mercury.

Poison nut. (Bot.)
   (a) Nux vomica.
   (b) The tree which yields this seed (Strychnos Nuxvomica). It is found on the Malabar and Coromandel coasts.

Poison oak (Bot.), the poison ivy; also, the more shrubby Rhus diversiloba of California and Oregon.

Poison sac. (Zo["o]l.) Same as Poison gland, above. See Illust. under Fang.

Poison sumac (Bot.), a poisonous shrub of the genus Rhus (R. venenata); -- also called poison ash, poison dogwood, and poison elder. It has pinnate leaves on graceful and slender common petioles, and usually grows in swampy places. Both this plant and the poison ivy (Rhus Toxicodendron) have clusters of smooth greenish white berries, while the red-fruited species of this genus are harmless. The tree (Rhus vernicifera) which yields the celebrated Japan lacquer is almost identical with the poison sumac, and is also very poisonous. The juice of the poison sumac also forms a lacquer similar to that of Japan.

Syn: Venom; virus; bane; pest; malignity.

Usage: Poison, Venom. Poison usually denotes something received into the system by the mouth, breath, etc. Venom is something discharged from animals and received by means of a wound, as by the bite or sting of serpents, scorpions, etc. Hence, venom specifically implies some malignity of nature or purpose.

Source: Webster's Revised Unabridged Dictionary (1913)