Use of the inoculation knife from 1817 Chinese casebook

Drawing of the hand of a doctor using an inoculation knife from Sun Shi yi'an (Doctor Sun's Casebooks) by Sun Qishun (Qing period, 1644-1911), dated 1817 (22nd year of the Jiaqing reign period of the Qing dynasty, Ding Chou year).

Doctor Sun's Casebooks run to 68 juan (volumes). In them, Sun Qishun records a variety of case histories under the rubrics 'Nei' (Internal), 'Wai' (External), Fu (Gynecological), Er (Paediatric) and Wu guan (Five sensory organs). This illustration comes from Book 1: 'Inoculation with cowpox'.

The text states: During inoculation (zhongdou) inoculation, one should not insert the knife vertically. Manipulating the knife lightly and delicately, one should puncture the skin laterally, lifting up a paper-thin layer of epidermis. The entry point should be about 0.1 cun (c. 0.3 cm) in width. After puncturing, one should press the point of the knife very gently inwards and then withdraw it, so that a very small quantity of blood is seen. The book warns that one must avoid any sudden, undue use of force, so as not to cause excessive bleeding, which may flush away the pox germs making it impossible to achieve the objective of inoculation.