The indelibility of tattoo-marks is such that their traces may be easily recognized in the cadaver, though in a somewhat advanced stage of putrefaction. They have even been recognized on a gangrenous limb. Sometimes, however, it is impossible to recognize at first sight whether there has or has not been a tattoo. A strong light and a magnifying glass and a microscopic examination of the neighboring ganglia to detect the presence of coloring matter may assist in removing doubt. It has been found on the bodies of tattooed cadavers that the ganglia are filled with grains of coloring matter of the same nature as that employed in making the tattoo. Attempts to remove tattoo-marks generally leave a vicious scar that is equally indelible. An efficacious method is to tattoo the mark with a solution of tannin, which is followed by brushing over with nitrate of silver. A red cicatrix follows, and when the epidermis separates the tattoo disappears. A better method, however, is by means of the electric needle already mentioned in speaking of the electrolysis of nævi.
That a tattoo-mark may disappear by the effects of time and leave no trace is a matter that Cooper reports after examining the mutilated remains of a cadaver, and the statistics of Caspar, Tardieu, and Hutin place it as high as nine in the hundred. An officer of the United States Revenue Marine lately called my attention to several superficial tattooes on the back of his hand which had disappeared. The deeper ones, however, remained. The spontaneous disappearance of a tattoo seems to be possible when the operation has been done in such a superficial way as not to have passed the rete Malpighii, or when the tattooing has been done with some substance not very tenacious, as vermilion, which appears to be easily eliminated. But when the particles of coloring matter penetrate into the fibro-elastic tissue of the derma, the disappearance of the tattoo is rare.
In seventy-eight individuals tattooed with vermilion alone, Hutin found eleven upon whom the tattoo had disappeared. Out of one hundred and four tattooes made with a single color, India-ink, writing ink, blue or back, not a single one had completely disappeared. The results are identical if the tattooes are made with two colors. Thus in 153 tattooes with vermilion and India-ink, one instance showed a fading of the black, in another it had completely disappeared, the red being well marked; twenty times the red was partly effaced, the black being well marked; and in sixteen cases the red had completely disappeared, the black remaining visible.[592]
A tattoo-mark may sometimes be altered, in which case it proves deceptive as an index. A workman changing his trade seeks to transform the insignia of his first calling into those of the second, or a criminal in order to avoid identity will make a change. In the former instance the transformation is not difficult to detect, but in the latter so much care is required to recognize the change that penal science has relegated the sign to a secondary place.
As to the length of time since a tattoo-mark has been executed, authorities are that it is impossible to tell after two or three weeks. Whether a tattoo-mark is real or feigned is easily settled by simply washing the part. This question, as well as that of the judicial consequences of such marks, is hardly pertinent to the matter in hand.
Value of Professional Stigmata.
The so-called professional signs are of undoubted value in the surface examination for establishing identity, but it does not seem that their importance warrants the extreme prolixity given to them by some Continental writers, and even by one in the city of Mexico, Dr. Jose Ramos.[593] For instance, it is pretended that cataract is more common among jewellers because of the fineness of their work; yet out of 952 cataracts, of which a record has been kept, only two cases occurred in jewellers. Besides, there is not one special sign or physical trace left on the body by which a prostitute may be known, notwithstanding the fact that in life the collective appearance would seldom deceive an experienced man.
Only in the case of sodomy, where anal coitus has been frequent, would characteristic signs be found. On anal examination of 446 prostitutes, Dr. Coutagne[594] found the signs of post-perineal coitus in 180. He cites the case of a young prostitute presenting the astonishing contrast of a gaping anus surrounded by characteristic rhagades, with the genital parts of an extreme freshness, a very narrow vagina, and non-retracted hymen, constituting by their reunion a still firm ring. A fact yet more curious is shown by a specimen in the collection of the museum of the laboratory of legal medicine at Lyons. The genital organs of the cadaver of a woman of twenty-eight or thirty years showed a hymen intact and firm, but on examining the anal region it was surprising to find an infundibuliform deformity with all the signs of sodomitical habits, which of course rectified the opinion that had been made regarding the chastity of this woman.
Many of the signs enumerated as peculiar to different callings have no special anatomical characteristic that is easy to distinguish with precision, consequently they do not present a degree of certainty or constancy sufficient to be invoked as strong medico-legal proof of identity. Moreover, the effects of time or treatment may have caused alteration or disappearance of many of the signs in question, which would at best be of negative rather than of absolute value.
To arrive at an impartial appreciation of the relative value of the professional stigmata as signs of identity, a certain number of the signs should be thrown aside as illusory. Others, on the contrary, are durable, special, and constant, and assist in establishing the identity accordingly as the lesions or alterations are complete or evident; but it should be borne in mind that the physical alterations and chemical modifications resulting from the exercise of certain trades are not in our country so important from a medico-legal point of view as they are in Europe, where class distinctions are more defined.