Once upon a time, a
Katana was tested on a live
human being. The test, called "
Tameshigiri", was both a test of the
blade and a first
blooding of the
weapon, kind of a sacrifice to
the spirit of the blade. The test subject was usually a
condemned criminal, although useless
slaves were sometimes also used. After a time,
corpses became the test subjects, then bundles of
bamboo or
straw, as it became less
politically correct to test swords on people.
The need for a Samurai to have the confidence that his sword will perform as promised, coupled with the desire to "blood" the weapon, started the practice known as the "crossroads cut". The young samurai would go to a crossroads and wait for the next person to come down the road, then kill them with a hip-to-shoulder cut, the primary katana test cut.
Needless to say, this practice also fell out of favor. In World War II, Nakamura Taizaburo, who eventually became the head of the Toyama Ryu school (www.toyama-ryu.com), performed Tameshigiri on living cattle.
Today Tameshigiri is performed on rolled tatami mats, in bunches or with wood or metal cores.