Enquire within upon everything by Robert Kemp Philp

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.