The ''jian'' (; Cantonese: Gim) is a double-edged straight sword used during the last 2,500 years in China. The first Chinese sources that mention the ''jian'' date to the 7th century BCE during the Spring and Autumn Period;〔Ebrey 1999, p. 41〕 one of the earliest specimens being the Sword of Goujian. Historical one-handed versions have blades varying from in length. The weight of an average sword of blade-length would be in a range of approximately 700 to 900 grams (1.5 to 2 pounds).〔Rodell 2003, p. 19〕 There are also larger two-handed versions used for training by many styles of Chinese martial arts. Professional ''jian'' practitioners are referred to as ''jianke'' () or "swordsmen", a term dating from the Han dynasty.
In Chinese folklore, it is known as "The Gentleman of Weapons" and is considered one of the four major weapons, along with the ''Gun (staff)'', ''Qiang (spear)'', and the ''Dao (sabre)''. These swords are also sometimes referred to as ''taijijian'' or "t'ai chi swords", reflecting their current use as training weapons for taijiquan practitioners, though there were no historical jian types created specifically for taijiquan.〔Rodell (2003), p. 20〕
==Parts of the ''jian''==
A guard or hilt protects the hand from an opposing blade.
The shape of the guard can be described as short wings pointing either forward or backward. A minority of ''jian'' featured the disc-shaped guards associated with ''dao''. A handle behind the guard can accommodate the grip of both hands or one hand plus two or three fingers of the other hand. Two-handed ''jiàn'' of up to in length, known as ''shuangshou jian'', existed but were not as common as the one-handed version. The longer two-handed handle could be used as a lever to lock the opponent's arm if necessary. Grips are usually of fluted wood or covered in rayskin, with a minority being wrapped with cord.
The end of the handle was finished with a pommel for balance, to prevent the handle from sliding through the hand if the hand's grip should be loosened, and for striking or trapping the opponent as opportunity required — such as in "withdrawing" techniques. The pommel was historically peened onto the tang of the blade; thereby holding together as one solid unit the blade, guard, handle, and pommel. Most ''jian'' of the last century or so are assembled with a threaded tang onto which the pommel or pommel-nut is screwed.
Sometimes a tassel is attached to the hilt. During the Ming Dynasty these were usually passed through an openwork pommel, and in the Qing through a hole in the grip itself; modern swords usually attach the tassel to the end of the pommel. Historically these were likely used as lanyards, allowing the wielder to retain the sword in combat. There are some sword forms which utilize the tassel as an integral part of their swordsmanship style (sometimes offensively), while other schools dispense with sword tassels entirely. The movement of the tassel may have served to distract opponents, and some schools further claim that metal wires or thin silk cords were once worked into the tassels for impairing vision and causing bleeding when swept across the face. The tassel's use now is primarily decorative.〔Sugawara 1998, p.204〕〔Zhang 1998, pp. 38-39〕
The blade itself is customarily divided into three sections for leverage in different offensive and defensive techniques. The tip of the blade is the ''jiànfeng'', meant for stabbing, slashing, and quick percussive cuts. The ''jiànfeng'' typically curves smoothly to a point, though in the Ming period sharply angled points were common. Some antiques have rounded points, though these are likely the result of wear. The middle section is the ''zhongren'' or middle edge, and is used for a variety of offensive and defensive actions: cleaving cuts, draw cuts, and deflections. The section of blade closest to the guard is called the ''jiàngen'' or root, and is mainly used for defensive actions; on some late period jian, the base of the blade was made into an unsharpened ricasso. These sections are not necessarily of the same length, with the ''jiànfeng'' being only three or four inches long.〔Rodell 2003, pp.22-23〕〔Zhang 1998, pp.37-38〕
Jian blades generally feature subtle profile taper (decreasing width), but often have considerable distal taper (decreasing thickness), with blade thickness near the tip being only half the thickness of the root's base. Jiàn may also feature differential sharpening, where the blade is made progressively sharper towards the tip, usually corresponding to the three sections of the blade. The cross-section of the blade is typically that of a flattened diamond with a visible central ridge, though some are lenticular (eye-shaped) instead; ancient bronze jian sometimes have a hexagonal cross-section.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』