B. After four or five minutes, prickling, later burning, and at last a sensation like that of a hot iron upon the parts. In twenty or twenty-five minutes the pain increases so much as to be scarcely bearable. On removal of the mustard the access of air to the part increases the pain still more. Redness accompanies the pain. The pain may last for several days, but the redness lasts longer, and every evening is accompanied with a not unpleasant pruritus. If the application be very prolonged, or repeated, vesicles form, which on disappearing leave indelible macules, 17, 295. Pain, pustules, and finally erysipelatous inflammation, 1, 410.

Remarks

The only officinal preparation is Charta Sinapis.