ARM

ARM, Brachium, a part of the human Body, terminating at one End in the Shoulder, and at the other in the Hand. See BODY, SHOULDER, etc. Among Physicians, the Arm only includes that part between the Shoulder and the Elbow; the rest, from the Elbow to the Wrist, being taken into the greater Hand. See HAND.

The Arm, in this latter Acceptation, has only one large Bone, called the Humerus, or Shoulder-Bone. See HUMERUS.



It has five sorts of Motions, which are effected by five Pair of Muscles; upwards, by the Deltoides, Supraspinatus, and Coracobrachialis; downwards, by the Teres, Rotundus major, and Latissimus Dorsi; forwards, by the Pectoralis; backwards, by the Infraspinatus; and circular, by the Transversalis, Subscapularis, and Infraspinatus. See each Muscle described under its proper Article.

The other Part consists of two Bones, called Fossils; viz. the Radius and Ulna. See FOSSIL, RADIUS, and ULNA.

The Muscles whereby this Part are moved, are the Biceps, Brachialis Internus, Gemellus, Brachialis Externus, Anconeus, Pronator Radii Teres, and Quadratus; Supinator Longus, & Brevis. See each in its Place.

The usual Venesections are in the Arm. See VENESECTION.

Arm, in the Manage, is applied to a Horse, when he endeavours to defend himself against the Bit; to prevent obeying, or being checked thereby. A Horse is said to arm himself, when he presses down his Head, and bends his Neck, so as to rest the Branches of the Bridle upon his Brisket; in order to withstand the Effort of the Bit, and guard his Bars and his Mouth. A Horse is said to arm himself with the Lips, when he covers the Bars with his Lips, and deadens the Pressure of the Bit.—This frequently happens in thick-lipped Horses— The Remedy is by using a Bit-mouth, forged with a Canon or Scatch-mouth, broader near the Bankers than at the Place of its Pressure, or rest upon the Bars. For arming against the Bit, the Remedy is to have a wooden Ball covered with Velvet, or other Matter, put on his Chaul; which will so press him between the Jaw-bones, as to prevent his bringing his Head so near his Breast.

Arm, is also used in Geography, for a Branch of a Sea, or River. See SEA, OCEAN, RIVER, etc. Italy and Sicily are only parted by an Arm of the Sea. The Arm, in the Mediterranean, is the Thracian Bosporus.

Among Gardeners, Arm is sometimes used in respect of Cucumbers and Melons, in the same Sense as Branch, of other Plants. See BRANCH, GRAFT, etc.

Age is used figuratively for Power. The Secular Arm, is the Lay or Temporal Authority of a secular Judge; to which Recourse is had for the Execution of the Sentences passed by Ecclesiastical Judges. See SECULAR. The Church sheds no Blood: Even the Inquisition, after they have found the Person guilty, surrenders him to the secular Arm. See INQUISITION.

The Council of Antioch, held in 341, decrees, that Recourse be had to the Secular Arm to repress those who refuse Obedience to the Church: For secular Arm, they here use exterior Power.

Arm, in the military Art, Heraldry, etc.

See ARMS and ARMOUR.

Arm, in the Sea-Language.

A Ship is said to be armed when fitted out and provided in all respects for War. See SURE.

Also, a Cross-Bar-shot is said to be armed, when some Rope-yarn, or the like, is rolled round about one End of the Iron-Bar which runs through the Shot, both that the Shot may be the better rammed down into the Gun, and lest the sharp End of the Bar should catch into any Honey, Combs within the Cylinder of the Piece.

Arm, in respect of the Magnet.

A Lodestone is said to be armed, when it is capped, cased, or set in Iron or Steel, in order to make it take up the greater Weight; and also to distinguish readily its Poles.

See MAGNET, POLES, etc.

The usual Armour of a Lodestone in form of a right-angled Parallelepipedon, consists of two thin Pieces of Steel or Iron, in a square Figure, and of a Thickness proportionable to the Goodness of the Stone: If a weak Stone have a strong Armour, it will produce no Effect; and if the Armour of a strong Lodestone be too thin, its Effect will not be as considerable as when thicker. —The proper Thickness is found by filing it thinner and thinner, till its Effect is found the greatest possible.

The Armour of a Spherical Lodestone, consists of two Steel Shells fastened to one another by a Joint, and covering a good Part of the Convexity of the Stone. This also is to be filed away, till the Effect is found the greatest.—It is surprising to what Degree the Armour of a Lodestone will augment its Effect: A good Stone thus armed, will lift above 150 times more than before. See MAGNETISM.

Kircher, in his Book "De Magnete," tells us, that the best way to arm a Lodestone, is to drill a Hole through the Stone from Pole to Pole, and in that, to place a Steel Rod of a moderate Length; which Rod, adds he, will take up more Weight at the End, than the Stone itself arrayed the common Way, can do.

Arma dare, q.d. to give Arms, in some ancient Charters, signifies to dub, or make a Knight.

See KNIGHT.

Arma deponere, to lay down Arms, was a Punishment anciently enjoined when a Man had committed an Offence.

Leg. Hen. I.

Arma Molita, were sharp Weapons; Fiera calls them Arma Emolita.

Arma Mutare, q.d. to change Arms, was a Ceremony used to confirm a League or Friendship.

Arma Reversata, Inverted Arms; was when a Man was convicted of Treason or Felony.

See DISPARATION, etc.

ARM