842. Leeches and their Application
The leech used for medical purposes is called the
hirudo medicinalis
to distinguish it from other varieties, such as the horse-leech and the Lisbon leech. It varies from two to four inches in length, and is of a blackish brown colour, marked on the back with six yellow spots, and edged with a yellow line on each side. Formerly leeches were supplied by Lincolnshire, Yorkshire, and other fenny countries, but latterly most of the leeches are procured from France, where they are now becoming scarce.
843. When Leeches are Applied
When leeches are applied to a part, it should be thoroughly freed from down or hair by shaving, and all liniments, &c., carefully and effectually cleaned away by washing. If the leech is hungry it will soon bite, but sometimes great difficulty is experienced in getting them to fasten. When this is the case, roll the leech into a little porter, or moisten the surface with a little blood, or milk, or sugar and water. Leeches may be applied by holding them over the part with a piece of linen cloth, or by means of an inverted glass, under which they must be placed.
844. When applied to the Gums