OLIG. lahhi, Mehl, physician, from Mr, medicine; the worm is so called from its medic inal use). The application of leeches for the purpose of abstracting blood. This method of blood-letting is employed in medicine in place of cupping or venesection in the case of local inflammation or acute congestion. Having at tached itself to the integument by means of teeth and suction apparatus, the leech secretes a liquid which prevents the blood from coagu lating; and hence the persistent bleeding in some eases after a leech is removed. A leech is most easily applied by, inserting it tail end first in a small, narrow bottle, and then inverting the bottle against the skin, and letting the leech slide down. If it refuses to bite, a few drops of sweetened milk or of blood put on the skin will overcome its reluctance and incite it to attach itself. The leech may be detached by sprinkling salt on it. At each application a leech ordinarily takes about one drachm of blood. It may he made to disgorge by treating it with salt, or by stripping it gently from tail to head. Leech-bites leave deep and
permanent though small sears. Leeches are em ployed in eases of meningitis, in conjunctivitis, in purulent inflammation of the external ear, and in the treatment of swollen joints. such as occur after a traumatism. The troublesome bleeding which follows in some cases is treated with styp tics, or with pressure of a gauze compress over the wound.
The use of leeches is not cleanly nor aseptic, and occasionally infection follows. Hence many prefer to employ the 'artificial leech,' which con sists of a tube provided with a piston for exhaust ing the air within it. A scarificator having first been used, the margin of the end of the tube in anointed and placed firmly against the skin, and the air exhausted. Blood pa—es out into the tube. The best 'artificial leech' is that devised by Leach of New York.