In case good, old-fashioned medicine makes a comeback, you may need to know how to leech someone. Here are your instructions from a book written in 1858:
“Leeches and their application: The leech used for medical purposes is called the hirudo Medicinatis, 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 fellow line on each side. Formerly leeches were supplied by Sweden but latterly most of the leeches are procured from France, where they are now becoming scarce.
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 on. 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 port with a piece of linen cloth or by means of an inverted glass, under which they must be placed.
When applied to the gums, care should be taken to use a leech glass, as they are apt to creep down the patient’s throat; a large swan’s quill will answer the purpose of a leech glass. When leeches are gorged they will drop off themselves; never tear them off from a person, but just dip the point of a moistened finger into some salt and touch them with it. Leeches are supposed to abstract about two drachms of blood, or six leeches draw about an ounce; but this is independent of the bleeding after they have come off, and more blood generally flows then than during the time they are sucking.”