knee-kick

If a quick glance at the pupils shows both smaller or larger than normal, and on turning his face to the light they fail to contract, your suspicion is confirmed; while if, on asking him to be seated and cross his legs, a tap on the great extensor tendon of the knee-joint just below the patella fails to elicit any quick upward jerk of the foot, the so-called "knee-kick," then you may be almost sure of your diagnosis, and proceed to work it out at your leisure.

Preventable Diseases Woods Hutchinson 1896