Dr Baron Charles Louis Heurteloup (1793 – 1864) invented an artificial leech which was named after him. These were often used to bleed sensitive areas around the eyes or temples.

After the cut had been made the glass tube would be placed over it and the wing nut turned to create a vacuum in the tube which would draw up the blood. More commonly they have a short scarifier which works by pulling back and releasing a sprung lancet, or a string mechanism for rotating a circular knife. This one also uses a circular knife but is unusual in that the mechanism for doing so is the withdrawing or advancing the piston.

• From the Phisick collection