Second line, rolled impressions of whorl (thumb), ulnar loop (third finger).
Eyes and Veins.—The angle of the eyes to the middle line of the face is an aid to identity; this will show whether the equator of the eye is on a plane at a right angle to the middle line, or above or below it. Tamassia lays much stress upon the arrangement of the veins on the back of the hands, which is an individual characteristic and one which is not easily altered or likely to be. By compressing the arms with a ligature the veins are made to stand out in relief and the backs of the hands are photographed.
Other Peculiarities.—The identity of the accused may be further proved by the absence or malformation of the teeth corresponding with a bite on the party assaulted, or the impression of the teeth on soft articles like cheese. Peculiarities of dentistry may be useful in identification. Or it may be proved that the wound inflicted could only have been made by a left-handed person, or in a manner peculiar to those engaged in the slaughtering of animals—e.g. is the cut from within outwards, as employed by butchers? The correspondence in the size and peculiarities of the foot of the prisoner and the footprints found in the vicinity of the crime is important as evidence. There is considerable difference of opinion as to the size of a footprint on the ground, Mascar of Belgium asserting that it is smaller than the foot that made it, Caussè, on the contrary, that it is usually larger. It should be borne in mind that the size of the footprint varies in running, walking, and standing, being smallest in running and largest when the individual is standing, which may account for the difference of opinion of the two observers just mentioned. This fact should always be borne in mind when an examination is required to be made of the footprints in the neighbourhood of the crime. A mark in the footprint showing that the sole of the boot had been patched, or in the case of the naked foot that there was some deformity of the toes, would of necessity be important. The mark of the naked foot smeared with blood has, in several cases, led to the identification of the culprit. Photographs may be used as a means of identification. Casts of footprints may be taken by smearing the print carefully with oil, and pouring in liquid plaster of Paris, or by dusting it over with powdered paraffin wax, and then melting it by holding a hot iron over the print; this may be repeated until a sufficiently thick cast is obtained. Hot solution of gelatine in water, mixed with oxide of zinc and glycerine to the requisite consistence, may be used for the purpose.
Dyeing of Hair.—As a means of disguise the hair may be dyed, or the colour may be changed from dark to light. For darkening the hair, preparations containing permanganate of potash, or the acetate of lead, bismuth, or nitrate of silver, are most frequently employed. Sticks of nitrate of silver or lunar caustic are used for darkening eyebrows and moustachios. A wash containing sulphide of potassium is used before the application of the lead solution. This removes the grease, and helps the rapid formation of the black sulphide of lead. Preparations of henna are fashionable for the production of shades of copper to rich brown. To detect fraud, some of the suspected hair should be steeped in dilute nitric acid, the acid driven off by gentle heat, and the nitrate dissolved in distilled water, and then sulphuretted hydrogen passed through the solution, the result being the formation of the black sulphide of lead. If silver be present, the addition of hydrochloric acid will throw down the insoluble chloride of silver. If careful examination be made of dyed hair, it will be found that the dye is irregularly taken by the hair; the hair loses lustre, and I have not unfrequently seen the hair close to the scalp white, or at least several shades lighter than the rest. The scalp may also be seen more or less discoloured, especially when nitrate of silver is used and applied by the individual himself.
For lightening the natural colour, solutions of chlorine, of peroxide of hydrogen, nitric and nitro-hydrochloric acids, of varying strengths, are used. It must be remembered that the action of chlorine is by no means uniform. The hair retains the odour of chlorine for some time, even after repeated washing, and is hard, stiff, and brittle. Devergie states that he has not succeeded in producing a perfect whitening of the hair in less than from twelve to twenty hours. It must be borne in mind that, under certain circumstances, dark hair may become suddenly white. I have seen large patches of grey hair over the head, the result of repeated attacks of neuralgia.
In the examination of persons whose hair is alleged to have been dyed, it is necessary to compare the dyed hair with that from other parts of the body, e.g. the pubes, or axilla, to wait and watch for irregularities of colour as the hair grows, new growth being free from dye, and if necessary to shave the part and compare the new growth with other hair, also to examine carefully the skin in the position where the dye has been applied. In one case which I noted, a man had been in the habit of touching the moustachios and eyebrows with lunar caustic, having previously damped it with his tongue; in time it produced argyria which coloured the whole of his face, the body generally, but most noticeable on the face.
Fig. 3.—Photo-micrograph of transverse section
of normal hair follicle, × 250.
(R. J. M. Buchanan.)
Examination of a Person said
to have been Assaulted
Carefully examine the bruises, wounds, &c., to see if they could have been inflicted as described. Ask no questions that may suggest an answer. Examine all weapons said to have been used, and hand them over to the police. In all cases where danger to life is imminent, send for the Authorities, and take dying declarations, as these may become evidence of vast importance, and, if properly taken, are as valid as if given on oath.