MEDICAL JURISPRUDENCE The letters "P. L." tattooed on the left forearm were evident in a badly decomposed body examined a fortnight after death.59 A faded tattoo-mark may be revealed by the use of the ultra-violet lamp, or may be rendered Fig. 15.—Designs of Tattoo-marks. visible by rubbing the part and examining it with a magnifying lens in strong light. Artificial removal of Tattoo-marks.—These may be removed artificially (1) by the surgical method, (2) by electrolysis, and (3) by the application of caustic substances. (1) Surgical Method.—The earliest surgical method employed for the removal of tattoo-marks was the production of a burn by the application of a red-hot iron to the design. When the dead tissue sloughed off, it took the tattoo-mark with it but usually left a bad scar in its place. The use of carbon dioxide now produces similar results. The simplest surgical method used at present is the excision of the tattoo-marks with or without skin grafting. This is quite a successful method but is always followed by some scarring. Lacassagne and J. Rousel60 recommend the scarification of the tattooed spots and then sprinkling over with finely powdered potassium permanga- nate. After a few days the scab falls off, and a smooth, colourless, almost unscarred skin appears. (2) Electrolysis.—Miller61 suggests electrolysis for the removal of tattoo-marks by means of a needle attached to the negative pole of a battery in order to get the softening action of the alkali formed there. After the pigment is laid bare by the needle, it is scraped and picked away, as the softening action of the alkali continues on the tissues in which the pigment is deposited. Another method is to insert the needle into the tattoo-mark a sufficient number of times, using a current of 5 to 8 milliamperes. This 59. K. E. v. Mangali, All. H. Crfc. Criminal Appeal No. 149 of 1921. 60. Bull. Soc. Franc. Dermat. 37, No. 4, 1930 ; Ars. Medici, Nov. 30, 1930, p. 124. 61. Electrolysis for the Removal of Tattoo-marks, Medical Council, Philadelphia, 13, 374, 1908 ; Jour, Amer. Med. Assoc., Jan. 14, 1928, p. 94.