tact and of preventing the collecting of serum and, later, of pus. Treatment.-If deep, a drainage-tube should be passed to the bottom of the wound, and gradually shortened as the wound heals. If there is severe arterial hemorrhage which cannot be controlled by carefully applied pressure, the wound must be converted into an incised one, and the bleeding vessel treated in the way described under wounds of arteries, veins, etc. For the special treatment required where a joint or visceral cavity has been penetrated, see Injuries of Regions.

POISONED WOUNDS.-Dissection and Post-mortem Wounds.Dissection wounds are of frequent occurrence, but seldom give rise to any serious trouble, unless the body from which the poison is received is fresh, when the risks are similar to those attending wounds received in making post-mortem examinations. Postmortem wounds appear to owe their virulence to inoculation with infective micro-organisms which are capable of multiplying in the tissues or in the blood, and so setting up true infective inflammation and blood poisoning. These micro-organisms are replaced, as decomposition of the corpse sets in, by the bacteria of putrefaction (bacterium termo). Hence the longer the body has been kept the less dangerous the wound, as these bacteria are merely capable of inducing a local inflammation, and not a true infective process. The most dangerous wounds are those received while examining bodies in which death has recently resulted from septicemia, pyæmia, diffuse or puerperal peritonitis and erysipelas. The effects of a wound received in dissection, or in post-mortem inspection, will depend in some degree upon the health of the operator; the strong and vigorous are better able to resist the toxic effects than others debilitated by prolonged study or work in a hospital ward. On the other hand, those acclimatized to the dissecting or post-mortem room are less liable to be affected than those who have but recently been engaged there.

The signs, as might be expected from what has been said above, vary considerably, depending, as they do, upon the nature of the poison received from the corpse and the previous state of the operator's health. Thus: 1. A pustule may form at the seat of inoculation, and, after breaking and scabbing, leave a raised, indolent, painful red sore, which may exist for months in spite of treatment. 2. The wound may become inflamed, the superficial, and, perhaps, the deep lymphatics implicated, and the axillary glands enlarged and pain ful, this condition being attended by sharp constitutional disturbance, often preceded by a rigor. Suppuration generally occurs in the wound, and sometimes also in the axillary glands. The prognosis is usually good. 3. With

or without the local signs of the preceding form, severe constitutional symptoms set in, preceded by a rigor, and rapidly assume a typhoid character. Diffuse suppuration occurs in the axillary glands, and may spread to the neck and side of the chest. The prognosis is very unfavorable, the patient often dying in from one to three weeks, or only recovering after a tedious convalescence, and then, probably, with a broken constitution. 4. Diffuse cellular or cellulo-cutaneous erysipelas is set up at the seat of wound, attended with the usual constitutional symptoms of these affections, and may rapidly spread up the limb and terminate in gangrene and death. The axillary glands in this form are not usually affected. 5. In addition to the local suppuration, a pyæmic state, with the formation of metastatic abscesses in various tissues and organs, sometimes occurs.

Treatment.-Immediately on its infliction the wound should be sucked and cleansed by a stream of cold water, and bleeding encouraged by tightly binding the part above the wound. Where the corpse is recent and death is known to be the result of some infective disease, the wound should be washed in strong carbolic lotion (some recommend its cauterization with caustic potash, or nitrate of silver), and then dressed with iodoform, and protected from further infection. If a wart, or indolent sore form, it should be destroyed by nitrate of silver, or other caustic, and the patient's health improved by tonics and change of air. If an infective inflammation be set up, the wound should be freely incised, and any abscess that may form in the axilla, or elsewhere, opened early; indeed, if there is much tension or brawniness of the parts, incisions should be made before pus is formed. The bowels in the meantime should be cleared by a brisk purge, and the strength supported by nourishments and stimulants.

Stings of insects sometimes cause troublesome local inflammation, which is occasionally of a diffuse character, and where a large extent of surface is stung, as by a swarm of bees, may be attended by symptoms of severe depression. Stings of the throat occasionally occur from swallowing a wasp, and are liable to be followed by cedematous laryngitis.

Treatment. The application of ammonia will at once relieve pain. Where there is severe depression, ammonia or alcohol must be administered. Scarification, or even laryngotomy, may become necessary in severe stings of the throat.

Stings of Serpents.-The bites of poisonous snakes, other than the adder, are fortunately rare in this country. The bite of the common adder is seldom fatal. It is attended with much collapse, nausea or vomiting, great pain in the part, swelling of the affected member, subsequent discoloration from blood extravasation, and

occasionally inflammation and suppuration. The treatment consists in sucking the part where practicable, applying a bandage tightly above the bite to prevent absorption of the poison, and the internal administration of stimulants. The local application of liquor potassæ or permanganate of potash, the injection of ammonia into the veins, and excision of the bitten part are recommended. For an account of the more serious symptoms attending the bite of the cobra and other venomous serpents of tropical countries, a larger work must be consulted.

SUBCUTANEOUS WOUNDS.-A wound, whether it be of the connective tissue, bone, muscle, tendon, or other structure, is said to be subcutaneous when the skin or mucous membrane remains intact. Such wounds differ from the open in that they heal by adhesive inflammation without suppuration, since, as long as the skin or mucous membrane covering the wounded part is unbroken, septic processes are effectually prevented. Moreover, they are attended by but little, if any, constitutional disturbance. They will be further described under Rupture of Muscles and Tendons, Simple Fractures, etc.

DISEASES OF CICATRICES.-The cicatrices left on the healing of a wound are liable to certain affections, which may be enumerated as: 1, painful cicatrix; 2, depressed or contracted cicatrix ; 3, warty cicatrix; 4, thin cicatrices; 5, ulceration; 6, keloid; and 7, epithelioma. See Ulceration, Tumors, Injuries and Diseases of Nerves, etc.

CONTUSIONS OR BRUISES.

CONTUSIONS are subcutaneous injuries, occasioned by a crushing, pulping, or tearing of the tissues, combined with extravasation of blood consequent upon the rupture of the capillaries and smaller vessels of the part. In their slighter forms they constitute the common injury known as a bruise. The effused blood generally makes its way in the connective-tissue planes toward the skin, giving rise to the characteristic purplish-black appearance, and, as it later becomes absorbed, to a change of colors from bluish-black through dark red to yellowish-green. In severe cases the cuticle is raised into bullæ by the effusion of bloodstained serum beneath it. These bullæ, together with the black color of the part, may occasion a close resemblance to gangrene, from which, however, a contusion may be distinguished by there being no loss of heat or of sensation in the part, and by the bullæ being fixed, and not changing their position on pressure as in gangrene. In very severe and extensive contusions, however, the tissues may be so injured as to lose their vitality, and gangrene actually ensue; while in other instances inflammation

and suppuration may occur. When the contusion is localized, blood in considerable amount may be poured out at the injured spot, forming a fluctuating swelling known as a hæmatoma. Contusions of muscle, bone, blood-vessels, and nerves, and of the viscera, are considered separately under Injuries of Special Tissues and Organs.

Treatment. Beyond placing the part at rest, and applying an evaporating or a spirit lotion, nothing more as a rule is required, as the extravasated blood presses upon the injured vessels, and so prevents further hemorrhage. Should a hæmatoma form, it should on no account be opened, as the blood will usually become absorbed; while, if air be admitted, suppuration will probably ensue.

BURNS AND SCALDS.

BURNS AND SCALDS vary in their effect according to their depth, extent, situation, and the age of the patient. An extensive though superficial burn on the trunk, head, or face, especially in a child, may be more serious than a deeper but limited burn on the extremities. A burn is usually said to be more severe than a scald, as the fluid producing the latter generally quickly cools and runs off. A scald, however, owes its severity to the large extent of surface usually implicated, and when produced by molten metal or boiling oil, which adheres to the part, is generally very serious. Burns and scalds, when severe, give rise to constitutional as well as local effects. The local effects may be considered under Dupuytren's division of burns into six degrees. These degrees, however, may be variously combined in the same burn.

IST DEGREE.-Simple erythema, due to increased flow of blood through the dilated vessels. No tissue destruction ensues, and no scar is left.

2D DEGREE.-Vesication, due to the exudation from the dilated capillaries of the cutis causing the superficial layers of the epithelium to be raised from the deeper in the form of blebs. No scar is left, as only the superficial layers of the epithelium are destroyed, and are reproduced from the deeper layers. Some slight staining of the skin, however, may subsequently remain.

3D DEGREE.-Destruction of the Cuticle and Part of the True Skin. The epithelium around the hair-follicles, in the sweatglands, and between the papillæ, escapes, and rapidly forms new epithelium over the granulating surface left on the separation of the slough. A scar results, but as it contains all the elements of the true skin, the integrity of the part is retained, and hence there is no contraction. It is the most painful form of burn, as the nerve-endings are involved but not destroyed.

4th Degree.-Destruction of the Whole Skin.—The sloughs are yellowish-brown and parchment-like; and their separation is attended by much suppuration. As the nerve-endings are completely destroyed, the pain is much less than in the former degree of burn. The epithelium which covers in the granulating surface is only derived from the margins of the burn, and the resulting scar consists of dense fibrous tissue. Hence the extensive contraction and great deformity which often result.

5TH DEGREE.-Penetration of the Deep Fascia and Implication of the Muscles.-Great scarring and deformity necessarily follow. 6TH DEGREE.-Charring of the Whole Limb.-The parts are separated by ulceration in the same way as in gangrene.

CONSTITUTIONAL EFFECTS.-When the burn is superficial and of small extent, there may be no constitutional symptoms; and even when it is deep, but limited to one of the extremities, as the foot or hand, they may also be slight. When, however, the burn is extensive, and especially when it involves the chest, abdomen, or head and neck, even although it is only of the first or second degree, the symptoms may be severe, more particularly when the patient is a child. They may be divided into three stages: 1. Shock and congestion. 2. Reaction and inflammation. 3. Suppuration and exhaustion.

IST STAGE.-Shock and Congestion.—The shock is often very great, especially when the burn is extensive, and involves the trunk, or head and neck. The patient is pale and shivering, the pulse feeble and fluttering, and the extremities are cold; he suffers little or no pain, and sometimes passes into a state of coma and dies, the chief post-mortem appearances being congestion of the internal organs, particularly the brain.

2D STAGE.-Reaction and Inflammation.—Reaction comes on from twenty-four to forty-eight hours after the burn. The pulse is full, strong, and rapid, the temperature rises, and there are other symptoms of fever. Inflammation is set up around the burnt part, and there is now danger of the absorption of the septic products derived from the putrefaction of the sloughs which are beginning to separate. The congestion of the internal viscera, so common in the former stage, may run on into inflammation; and pleurisy, pneumonia, peritonitis, or meningitis may supervene and prove fatal. Perforating ulcer of the duodenum, attributed to Brunner's glands taking upon themselves the function of the injured glands in the burnt skin, may now occur, and is said to most frequently begin about the tenth day.

3D STAGE.-Suppuration and Exhaustion.-During this stage, which sets in on the separation of the sloughs, there is still a danger of the patient succumbing to inflammation of the vis