#Tertiary Syphilis.#—­While the manifestations of primary and secondary syphilis are common, those of the tertiary period are by comparison rare, and are observed chiefly in those who have either neglected treatment or who have had their powers of resistance lowered by privation, by alcoholic indulgence, or by tropical disease.

It is to be borne in mind that in a certain proportion of men and in a larger proportion of women, the patient has no knowledge of having suffered from syphilis.  Certain slight but important signs may give the clue in a number of cases, such as irregularity of the pupils or failure to react to light, abnormality of the reflexes, and the discovery of patches of leucoplakia on the tongue, cheek, or palate.

The general character of tertiary manifestations may be stated as follows:  They attack by preference the tissues derived from the mesoblastic layer of the embryo—­the cellular tissue, bones, muscles, and viscera.  They are often localised to one particular tissue or organ, such, for example, as the subcutaneous cellular tissue, the bones, or the liver, and they are rarely symmetrical.  They are usually aggressive and persistent, with little tendency to natural cure, and they may be dangerous to life, because of the destructive changes produced in such organs as the brain or the larynx.  They are remarkably amenable to treatment if instituted before the stage which is attended with destruction of tissue is reached.  Early tertiary lesions may be infective, and the disease may be transmitted by the discharges from them; but the later the lesions the less is the risk of their containing an infective virus.

The most prominent feature of tertiary syphilis consists in the formation of granulation tissue, and this takes place on a scale considerably larger than that observed in lesions of the secondary period.  The granulation tissue frequently forms a definite swelling or tumour-like mass (syphiloma), which, from its peculiar elastic consistence, is known as a gumma.  In its early stages a gumma is a firm, semi-translucent greyish or greyish-red mass of tissue; later it becomes opaque, yellow, and caseous, with a tendency to soften and liquefy.  The gumma does harm by displacing and replacing the normal tissue elements of the part affected, and by involving these in the degenerative changes, of the nature of caseation and necrosis, which produce the destructive lesions of the skin, mucous membranes, and internal organs.  This is true not only of the circumscribed gumma, but of the condition known as gummatous infiltration or syphilitic cirrhosis, in which the granulation tissue is diffused throughout the connective-tissue framework of such organs as the tongue or liver.  Both the gummatous lesions and the fibrosis of tertiary syphilis are directly excited by the spirochaetes.