+Syphilitic Periods.+ (1) period of primary incubation—the time between exposure and the appearance of the chancre, from ten to ninety days, the average time being three weeks; (2) period of primary symptoms—chancre and bubo of adjacent lymph glands; (3) period of secondary incubation—the time between the appearance of the chancre and the advent of secondary symptoms,—about six weeks as a rule; (4) period of secondary symptoms—lasting from one to three years; (5) intermediate period—there may be no symptoms or there may be light symptoms which are less symmetrical and more general than those of the secondary period; it lasts from two to four years, and ends in recovery or tertiary syphilis; and (6) period of tertiary symptoms—indefinite in duration; the fifth and sixth may never occur, the disease being cured. +Primary Syphilis.+ The primary stage comprises the chancre or infecting sore or bubo. A chancre or initial lesion is an infective granuloma resulting from the poison of syphilis. The chancre appears at the point of inoculation, and is the first lesion of the disease. During the three weeks or more requisite to develop a chancre the poison is continuously entering the system, and when the chancre develops, the system already contains a large amount of poison. A chancre is not a local lesion from which syphilis springs, but is a local manifestation of an existing constitutional disease, hence excision is entirely useless. The hard chancre, or initial lesion, never appears before the tenth day after exposure, it may not appear for weeks, but it usually arises in about twenty-one days. The lesion commonly appears as a round, indurated, cartilaginous area with an elevated edge, which ulcerates, exposing a velvety surface looking like raw ham; it bleeds easily, rarely suppurates, does not spread, and the discharge is thin and watery. The bubo of syphilis is multiple, consisting of a chain of glands, freely movable, indurated, painless, small and slow in growth, and the skin over the bubo is normal. A positive diagnosis of syphilis can be made when an indurated sore is followed by multiple indolent glands or buboes in the groin and by the enlargement of distant glands. +Secondary Glands.+ The symptoms are noticed from four to six weeks after the stage of the induration of the chancre, and may continue to appear at any time, up to twelve months. The most constant are certain eruptions on the skin, faucial inflammation, and enlargement or induration of the lymphatic glands; others are febrile reaction, pains in the back or limbs, swelling of the joints, iritis and falling out of the hair.