+Symptoms.+ The symptoms of a boil are as follows: a red elevation appears, which stings and itches; this elevation enlarges and becomes dusky in color, a pustule forms that ruptures and gives out a very little discharge which forms a crust; inflammatory infiltration of adjacent connective tissue advances rapidly, and the boil in about three days consists of a large red, tender, and painful base, capped by a pustule and some crusted discharge. In rare instances, at this stage, absorption occurs, but in most cases the swelling increases, the discoloration becomes dusky, the skin becomes edematous, the pain severe, and the centre of the boil becomes raised. About the seventh day rupture occurs, pus runs out, and a core of necrosed tissue is found in the centre of a ragged opening. The hair follicle and the sebaceous gland, which have undergone necrosis, are found in this core. Healing by granulation will occur; the constitution often shows reaction during the progress of a boil. Boils may be either single or multiple, and the development of one boil after another, or the formation of several boils at once, is known as _furunculosis_. +Treatment.+ The treatment consists of crucial incision and the application of a wet dressing. +An Ulcer+ may be defined as the loss of substance due to necrosis of a superficial structure, and the causes of ulcers may be divided into (1) predisposing and (2) exciting. In the former, age, sex, occupation and social condition have to be considered. The exciting causes are traumatism and infection. The chief varieties of ulcers seen on the leg and foot are as follows: indolent or callous; varicose; tubercular; syphilitic; epitheliomatous; diabetic; perforating and blastomycotic. In indolent or callous ulcer, the cause may be divided into general and local. Among the former may be mentioned typhoid fever, chronic nephritis, anemia, poor hygiene, improper food, overwork, and lack of sleep. Local causes: old scar tissue, extremes of heat or cold, irritation of the tissues, injury, the presence of a foreign body such as dead bone, splinter, etc. +Symptoms.+ The most common location of these callous ulcers is on the inner side of the lower third of the leg. They show a great variety in size, shape, appearance and base, edges and surrounding area, and in accordance with these differences, many different names are applied to them. The size varies from a small ulcer less than one centimeter in diameter, sometimes found with varicose veins, to the large ulcerations which surround the leg and are called _annular_ ulcers. The shape may be round, very irregular, or funnel shaped. The base may be much or slightly depressed, or the granulations may be at a higher level than the surrounding edges. When the granulations are large, irregular, and bleed easily, they are spoken of as _exuberant_; when pale, soft and flabby, as _weak_ or _edematous_; when small and slowly growing, as _indolent_.