stance do not leave scars, while others without loss of substance produce permanent cicatrices.

The solution of this question requires the application of the ordinary laws of the repair of tissue after a division of continuity or loss of substance. When there is a loss of substance in an epithelial tissue, either skin or mucous membrane, which does not pass below the level of the epithelium, repair is effected by simple proliferation of epithelial cells, and no cicatrix is formed. When the lesion involves other deeper tissues, subcutaneous connective tissue, fat, etc., the process of repair follows one of three plans: (1) There may be immediate adhesion of the divided surfaces, the healing proceeding by primary intention. Here the exudation of fibrin is very slight and merely aids in the cohesion of the surfaces, while the formation of granulation tissue is so inconsiderable that it may be regarded as practically absent. (2) There may be an exudation of fibrin, serum, and leukocytes on the cut surfaces, delaying the adhesion of these surfaces which later unite by secondary intention, with the production of granulation tissue. (3) There may be an excessive exudation of serum, fibrin, and leukocytes; the surfaces suppurate, they do not adhere at all, and the wound fills up from the bottom with granulation tissue.

Upon the amount of granulation tissue formed will depend the extent and permanence of the scar, for this tissue is never entirely replaced, but becomes converted into dense cicatricial connective tissue. Any or all of the foregoing processes may occur in different parts of the same wound, but any wound, the healing of which has not occurred entirely through "primary intention," but has been attended with suppuration or infection, will, in every case, leave an appreciable scar.

As to the exact process that takes place in the union by primary intention, no uniform rule can be stated. The subject is of sufficient importance to warrant the following quotation from Thoma. "Macartney, Thiersch, and others have asserted, in regard to the healing of linear incisions, that in many cases the surfaces may unite so closely that the line of the wound is indistinguishable after a few days, and can at best be recognized only by alterations in the position of the parts. Direct union of the separated parts without the formation of cicatricial tissue is supposed to be possible; but this view has as yet received no conclusive demonstration. A new formation of tissue seems really to be necessary for firm union of the margins of a wound, although it may be very slight in amount. Histologic examination of the incision made in laparotomies shows that this new formation of tissue greatly depends on the general condition of the patient. As can readily be understood, it is only when death occurs by hemorrhage, sepsis, pyemia, or other pathologic condition that the laparotomy wounds can be examined histologically within a few days of operation. In such cases the surfaces of the wound are closely apposed, and its line is hardly visible. Fine strands of lymphoid cells accompanying the vessels are all that is to be seen. It is only in parts where the margins of the wound are slightly 1 General Pathology, American edition, 1896, p. 484.

apart that some red and white corpuscles, fibrin, and young connectivetissue cells are found. In addition to this, the margins of the wound show more marked infiltration with small cells. If, in such cases, the line of the wound is not visible throughout its length two or three days after operation, this is chiefly due to the close apposition of the parts produced by the sutures, but does not necessarily indicate any direct union. The more closely the margins of the wound are apposed, however, the more delicate will be the scar when healing is completed, and sometimes it really does subsequently become very difficult to see. Any loss of tissue which is converted into a linear wound by close apposition of living tissues covered with epithelium externally heals in a similar manner." It must be granted, therefore, from these considerations, that it is possible in rare cases for an incised wound, even though associated with loss of substance, to leave no demonstrable permanent

cicatrix.

2. A scar having once existed, may it be obliterated by time or by artificial means?

In order to reconcile the contradictory observations on this point it is again necessary to consider the character of the process by which the wound has healed. Caspar has observed the marks of the scarificator to disappear in two or three years. Devergie thinks such marks do not disappear, but may in time become less distinct. There can be no doubt that the marks of the scarificator made in youth are commonly seen in old age, a fact which is emphasized by Tidy. These observations, all of which may be correct, are to be explained only by the differences in the rapidity and completeness of the original healing process, and by the amount of cicatricial tissue then produced. Clean linear incised wounds of which the edges are properly apposed, and in which the healing process occurs without suppuration or excessive exudation, leave thin delicate scars that may gradually disappear. On the other hand, there is no reliable evidence that a cicatrix formed after considerable granulation or suppuration has ever spontaneously disappeared.

The statement of Ogston' that he has seen "all traces of several chancres" on the same individual disappear in six weeks has been doubted by some authors, but will excite no great surprise among venereal surgeons who have had much experience with the treatment of superficial chancroids.

The prominence of delicate scars left after primary union may be considerably diminished by prolonged treatment with massage. Deforming scars are often excised, but the resulting loss of tissue is almost invariably sufficient to produce an indelible, although less prominent, cicatrix. The distinctness of cicatrices may be temporarily increased by friction of surrounding parts, which causes hyperemia in the normal tissue, while the limited vascular supply of cicatricial tissue presents a corresponding increase in its blood content.

3. Can the age of a cicatrix be inferred from its appearance ? With very rapid healing of incised wounds it is stated by Thoma

1 Medical Jurisprudence, p. 60.

that the incision may be invisible at the end of three days, although firm union has not yet occurred. The appearance of a cicatrix formed after granulation depends upon the changes occurring in granulation tissue during its transformation into cicatricial tissue. At the end of

from seventy to ninety hours (Thoma) there are dilatation of the capillaries and increased redness about the edges of a wound healing by secondary intention. This soon leads to the formation of many new capillaries and the organization of the exudate. In ordinary incised wounds the process of healing is usually complete in two weeks, leaving a soft, hyperemic, red cicatrix. The process is more rapid in children than in old persons, in healthy subjects than in those enfeebled by disease, hemorrhage, or sepsis. Wounds of the lower extremities, where venous circulation is less active, sometimes heal more slowly than wounds of the upper extremities. Healing by granulation always requires more time than that by adhesion. When there has been extensive loss of substance, as in lacerated and contused wounds; when the edges are imperfectly approximated or are drawn apart by underlying muscles, by movements of joints, or by the restlessness of the patient; and especially when there have been infection and suppuration in a wound-union proceeds more or less by granulation, and the formation of a cicatrix requires much longer time.

After the cicatrix has completely organized the blood-vessels gradually shrink, the effused blood is disintegrated and removed by the lymphatics, the new connective tissue contracts, and there remains finally a segment of dense fibrous tissue with few cells and few blood-vessels, plainly marked off from the surrounding skin as a permanent cicatrix. It will readily be seen that the external appearances of a cicatrix will vary much at different periods of its organization. A fresh scar is soft, tender, may often be broken down by firm pressure, and is reddish brown in color, due to the pressure of dilated capillaries. variable period, usually not before a month or six weeks, the bloodvessels and connective tissue begin to contract, the cicatrix becomes firm and takes on a brownish color. After months or years it may have nearly disappeared, and the connective tissue is contracted, leaving a white, glistening, hard, insensitive scar.

At a

4. Can the nature of a wound be determined from the character of the scar?

Much may be inferred, and some positive conclusions may be drawn as to the mode of origin of a wound, by an examination of scars, as many cicatrices are quite characteristic.

Accidental wounds produced by crushing force and attended with laceration and destruction of tissue give large irregular depressed scars, and there may also be signs of old fractures of underlying bones.

Bullet wounds, when produced by a weapon held within a few inches of the body, produce scars that are larger than the bullet, irregular in shape, and usually surrounded by indelible powder-stains. When a bullet wound has been produced from a distance, the scar is depressed,

discoidal, and smaller than the bullet. In either case the scar at the point of exit of the bullet, from flesh as from bone, is larger than the scar at entrance.

Stab wounds leave triangular scars, smaller than the blade, and less depressed than the scars from bullet wounds.

Burns, when of sufficient intensity to cause death of tissue below the epidermis, are followed by irregular, flat, smooth cicatrices, corresponding in size to the original lesion. The extent of these cicatrices is frequently considerable, and the contraction of the new connective tissue may cause marked deformities. The cicatrices of burns, rather more frequently than those of other wounds, may undergo a progressive hypertrophy, with the production of a thick, firm mass of connective tissue, with atrophic blood-vessels and dilated lymphatics, known as keloid.

Surgical wounds usually result in clear linear cicatrices, but suppuration, extensive removal of tissue, and prolonged use of drainage-tubes may alter their appearance. The marks of wet cups frequently persist throughout life as one or two rows of six small triangular white scars. Venesection is usually performed on the median cephalic vein and leaves a linear cicatrix lying obliquely across the course of the vessel above the elbow. Vaccination scars may be found on the upper arm or calf of the leg as flat circular cicatrices, often showing depressions on the surface.

Sears from Diseases of the Skin.-Tuberculosis of lymph-nodes or bones frequently produces sinuses leading from the affected tissue to the surface. When these lesions heal spontaneously, the sinuses are replaced by contracting connective tissue, which leaves an irregular superficial scar, usually much depressed and comparatively immovable with the skin. Secondary syphilis of the skin may produce characteristic and permanent superficial white scars on the back of the neck, as well as many less characteristic brown plaques in other regions, especially on the shins. The cutaneous lesion of tertiary syphilis, arising from the gumma which destroys considerable tissue, leaves a large, irregular, frequently pigmented, depressed cicatrix. Small-pox pustules are followed by small, distinctly depressed cicatrices, the size, location, and general appearance of which are usually characteristic. Transverse superficial cicatrices of the lower abdominal wall are rarely missed after pregnancy, but may be seen also in very fat men.

5. Can the size of the original wound be determined from the scar?

The principle already stated with regard to the contraction of cicatricial tissue permits the general rule to be given that a scar is always smaller than the original wound. This contraction will be greatest in the long diameter of the areas of new connective tissue, whether these areas are superficial, as after burns, or extend irregularly among muscles and viscera, as after the healing of deep sinuses. The contraction will also increase, up to a certain limit, with the age of the cicatrix. Exceptions to these rules are seen in the case of some wounds inflicted in childhood. Vaccination scars, linear operation wounds, nevi and

the scars resulting from their removal, have all been observed in children to increase in size with the natural growth of the body.

Finally, in judging of the value of the evidence furnished by scars, it is essential to recognize the fact, frequently ignored, that one or more scars, identical in appearance and location, are often to be found on different individuals, and that the presence of these marks can seldom be considered a positive proof of identity.

Tattoo-marks. Some famous instances are recorded in the older annals in which the presence of a tattoo served as a means of identification. The medicolegal importance of these markings has certainly not decreased at the present time, but is perhaps greater than ever, for this curious and rather inexplicable custom remains a very common one among many classes of society. Sailors, soldiers, and miners furnish a large proportion of the cases commonly seen in America. Criminals, with the exception of the more intelligent class of swindlers and forgers, frequently indulge the taste. Lombroso devotes considerable attention to the subject of tattooing, and it has come to be recognized as a nearly constant feature of criminal anthropology. Lombroso and Marandon de Montyel 2 found that of 600 insane persons, 13 per cent. were tattooed, the frequency with which the marks were found being in inverse ratio to the grade of degeneracy. No case was seen in a patient with advanced psychic degeneration. So much more frequently were the aggressive and dangerous lunatics tattooed that Lombroso believes the presence of these marks might be made of diagnostic value between the dangerous and the comparatively harmless lunatics and criminals.

*

Women rarely allow themselves to be tattooed, except prostitutes, who frequently cover themselves with various designs, usually obscene.

The process of tattooing varies considerably with the operator, but consists essentially in making multiple needle punctures in the skin and carrying into these minute wounds particles of coloring-matter. Very naturally, from the necessary lack of asepsis, bacteria are often carried in with the coloring-matter, which is itself an irritant, and considerable inflammation usually results; the neighboring lymph-nodes are frequently inflamed and may receive a permanent deposit of pigment, demonstrable after death, and fatal general septicemia has occurred. From Blockley Hospital, Philadelphia, comes the report of the inoculation of nearly a score of persons with syphilis, by the same tattooer, who moistened the needle in his mouth while suffering from secondary lesions of the buccal mucous membrane.

The coloring-matter may be deposited in the epidermis, or deep in the rete mucosum, or in the subcutaneous connective tissue, in which latter case the resulting inflammation, by the production of connective tissue, insures the permanence of the stain. Of the many pigments employed in the process the red colors are usually vermilion (cinnabar), and the blue colors are indigo, cobalt, or Prussian blue, although any colored ink may be used. The ordinary black dye consists of carbon particles used in the form of India ink. Nitrate of 1 L'uomo deliquente. 2 Archives d'Anthropologies criminelles, 1892, p. 373.