sore and its neighborhood. The bandage should be used as follows: before getting out of bed spray the sore with hydrogen peroxid by means of an atomizer, dry off the froth with cotton, wash the leg with soap and water, dry it, and put on the bandage—all of which should be done before putting a foot to the floor. At night, after getting in bed, take off the bandage, wash it with soap and water, hang it over a chair to dry, and again cleanse the leg and ulcer. If these rules are not strictly observed, the Martin bandage will produce pain, suppuration, and eczema of the leg. Tubercular Ulcers (p. 152). Syphilitic Ulcers (p. 197).

A healthy ulcer is covered with small, bright-red granulations which bleed on touching, are painless, and grow rapidly. The edges are soft and show the opalescent blue line of proliferating epithelium. The sore is movable, the discharge is purulent and yellow, and the parts about are not inflamed.

Various Ulcers.-The fungous or exuberant ulcer is especially common in burns and other injuries when cicatricial contraction causes venous obstruction. The granulations form rapidly and mount above the level of the skin. These granulations bleed when touched. Burn them off with solid stick of silver nitrate, or cut them off with a sharp knife; stop hemorrhage if there be any, and strap or use the rubber bandage.

A varicose ulcer is usually single, is oval, round, or irregular in outline, and is most often seen above the inner malleolus. Its edges are thick, everted, and swollen. This swelling is largely due to edema, and is found to pit on pressure. The edges are not undermined, but slope gently to the floor of the ulcer. The floor is usually covered with rather large granulations which bleed freely on touching. In a varicose ulcer the destruction of tissue often begins at the margin of a congested area and advances toward the centre. Such an ulcer is usually surrounded by eczema.

Erethistic, irritable, or painful ulcers, which are very sensitive, are due to the exposure of nerve-filaments and destruction of their sheaths. They are especially found near the ankle, over the tibia, in the anus (fissure), or in the matrix of the nail (ingrowing nail). Curet an erethistic ulcer, and touch with pure carbolic acid or with the solid stick of silver nitrate. Chloral, gr. xx to the ounce, allays the pain; so do cocain and eucain for a time.

The indolent ulcer has no granulations and shows no

tendency to heal. It requires stimulating applications to increase the blood-supply.

The hemorrhagic ulcer bleeds easily and profusely. Pressure must be applied, and it is sometimes necessary to cut away or burn away the granulations.

Phagedenic Ulcer.-The phagedenic ulcer, which means the profound microbic infection of tissues debilitated by local or constitutional disease, is commonly venereal. This ulcer has no granulations and is covered with sloughs; its edges are thin and undermined, and it spreads rapidly in all directions. It requires the use of strong caustics or Paquelin's cautery followed by iodoform dressing and antiseptic poultices. Internally, use tonics and stimulants.

The callous ulcer is sunken deeply below the level of the skin. Its border is hard and knobby. Its floor shows no granulations, and is either smooth and glistening or foul and liver-colored. The discharge is thin and scanty, and the ulcer varies little in appearance from week to week or even from month to month. The treatment is scraping and cauterization of the ulcer; cutting through the edges by radiating incisions; application of antiseptic dressings, and a firm bandage. In some cases strap the ulcer. In severe cases cut the ulcer out and skin-graft.

A rodent or Jacob's ulcer is a superficial epithelioma developing from sebaceous glands, sweat-glands, or hairfollicles. It requires scraping and cauterization, or, what is better, excision.

Decubital ulcer, or bed-sore, is due to pressure upon an area of feeble circulation (p. 130).

Neuroparalytic or trophic ulcer is due to impairment of the trophic centres in the cord.

The perforating ulcer, a name given by Vesigne, commonly affects the metatarsophalangeal joint or the pulp of the great toe about a corn. The parts about the corn inflame, and pus forms and reaches into the bone. A sinus evacuates the pus by the side of the corn. As this ulcer may be present in anesthetic leprosy, paralyzed limbs, and tabes dorsalis, and as the part on which it occurs is apt to be sweaty, cold, and more or less anesthetic, and as the sore may be hereditary, it is usually set down as trophic in origin. Treatment of a perforating ulcer consists, according to Treves, in going to bed and poulticing. Every time a poultice is removed the raised epithelium around the ulcer is cut away and then the poultice is reapplied. In about two weeks an ulcer remains surrounded by healthy tissue. Treves treats this

sore with glycerin made to a creamy consistency with salicylic acid, to each ounce of which mx of carbolic acid have been added. He directs the patient to wear during the rest of his life some form of bunion-plaster to keep off pressure. If in a perforating ulcer the bone is diseased, it must be removed. This ulcer tends to recur in the same spot or in adjacent parts, and it may be necessary to amputate the toe or the foot.

The scorbutic ulcer is covered with a dark-brown crust, beneath which are pale and bleeding granulations. The parts adjacent are of a violet color.

Epitheliomatous, sarcomatous, tubercular, and syphilitic ulcers are considered under these respective diseases.

Fistula. A fistula is an abnormal communication between the surface and an internal part of the body, or between two natural cavities or canals. The first form is seen in a rectal fistula, a urethral fistula, or a biliary fistula, and the second form is seen in a vesicovaginal fistula. Fistulæ may result from congenital defect, as when there is failure in the closure of the branchial clefts, and can arise from sloughing, traumatism, and suppuration. Fistulæ are named from their situation and communications.

A sinus is a tortuous track opening usually upon a free surface and leading down into the cavity of an imperfectlyhealed abscess. A sinus may be an unhealed portion of a wound. Many sinuses may be due to pus burrowing subcutaneously. A sinus fails to heal because of the presence of some irritant fluid (as saliva, urine, or bile); because of the existence of a foreign body, as dead bone, a bit of wood, a bullet, a septic ligature, etc.; or because of rigidity of the sinus-walls, which rigidity will not permit collapse. The walls of a tubercular sinus are lined with a material identical with the pyogenic membrane of a cold abscess. Sinuses may be maintained by want of rest (muscular movements) and general ill-health.

Treatment. In treating a fistula, remove any foreign. body, lay the channel open, curet, swab with pure carbolic acid, and pack with iodoform gauze. In obstinate cases entirely extirpate the fibrous walls, sew the deeper parts of the wound with buried catgut sutures and approximate the skin-surfaces with interrupted sutures of silkworm gut. Fresh air is a necessity, and nutritious food and tonics must be ordered.

VIII, MORTIFICATION, GANGRENE, OR SPHACELUS.

Mortification or gangrene is death in mass of a portion of the surface of the living body-the dead portions being visible in contrast to ulceration or molecular death, in which the dead particles are too small to be seen and are cast away. Gangrene is in reality a form of necrosis. But clinically the term necrosis is restricted to molar death of bone or to death of parts below the surface. In gangrene the dead portions may either desiccate or putrefy. Gangrene may be due to tissue-injury, either chemical or mechanical, to heat or cold, to failure of the general health, to circulatory obstruction, to nerve-disorder, the nerves involved being the vasomotor or possibly the trophic, or to microbic infection. A microbic poison can directly destroy tissues. It can indirectly destroy them by causing such inflammation that the products obstruct the circulation. When the mortified portion is entirely dead the process is spoken of as "sphacelus."

Classification.-Gangrene is divided into the following three great groups:

(1) Dry gangrene, which is due to circulatory interference, the arterial supply being decreased or cut off. As venous return is still active, all fluid is taken up from the tissues, which shrivel and mummify.

(2) Moist gangrene, which is due to interference not only with arterial ingress, but also with venous return or capillary circulation, the dead parts remaining moist.

(3) Septic gangrene, arising from virulent septic matter coming from outside. In this form the septic process causes the gangrene, and is not merely associated with it.

There are many gangrenous processes which belong under one or other of the above heads, namely: congenital gangrene, a rare form existing at birth; constitutional gangrene, arising from a constitutional cause, as diabetes; cutaneous gangrene, which is limited to skin and subcutaneous tissue, as in phlegmonous erysipelas; gaseous or emphysematous gangrene, in which the subcutaneous tissues are filled with putrefactive gases and crackle on pressure; diabetic or glycemic, due to diabetes; hospital gangrene, which is defined by Foster as specific serpiginous necrosis, the tissues being pulpefied: some consider it a traumatic diphtheria; cold gangrene, a form in which the parts are entirely dead (sphacelus); hot gangrene, which presents some inflammation, as shown by heat; dermatitis gangrænosa infantum, or

the multiple cachectic gangrene of Simon; idiopathic gangrene, which has no ascertainable cause; mixed, which is partly dry and partly moist; primary, in which the death of the part is direct, as from a burn; secondary, which follows an acute inflammation; multiple, as gangrenous herpes zoster; diabetic gangrene, which arises during the existence of diabetes; gangrenous ecthyma, a gangrenous condition of ecthyma ulcers; pressure, which is due to long compression; purpuric or scorbutic, which is due to scurvy; Raynaud's or idiopathic symmetrical, which is due to vascular spasm from nerve-disorder; senile, the dry gangrene of the aged; venous or static, which is due to obstruction of circulation, as in a strangulated hernia; trophic, which is due to nutritive failure by reason of disorder of the trophic nerves or centers; thrombotic, which is due to thrombus; embolic, which is due to embolus; and decubital gangrene, or bed-sores due to pressure.

Dry or chronic gangrene, Pott's gangrene (Fig. 33), arises

from deficiency of arterial blood. Even in a person with healthy arteries dry gangrene may result from injury of the main trunk of an artery (lodging of an embolus, ligation, or laceration). Gangrene only follows injury when the anastomotic circulation fails to sustain the part. Obstruction. due to thrombus is not unusual in the diseased arteries of the aged. When an embolus lodges in an artery and causes gangrene, the case runs the following course: sudden severe pain at the seat of impaction, and also tenderness; pulsation above, but not below, this point; the limb below the obstruction is blanched, cold, and anesthetic; within forty-eight hours, as a rule, the area of gangrene is widespread and clearly evident; the limb becomes reddish, greenish, blue,