_Of the Character of the Syphilitic Poison._—“The venereal poison is only known by the _action_ which follows its application.” It has been observed, that it is only communicable by deposition; and that certain parts are essentially prone to its reception: these are the generative apparatus of both sexes. The poison is conveyed in the form of a purulent fluid; that of gonorrhœa from inflamed vessels with corresponding morbid action; that of syphilis, also from a purulent fluid emanating from the surface of an ulcer. The disease prevails only in the human race; it is impossible to transfer it to animals of a lower kind. John Hunter soaked lint in matter from a gonorrhœa and chancre, and introduced it into the vaginæ of bitches and asses without producing any effect. The same experiment was tried by interposing the purulent matter within the prepuce of dogs and male asses, and also by inoculation, but with no other effect than that of producing a common sore. The venereal poison attacks the human body in two ways, locally and constitutionally; the latter by absorption of the poison secreted by the patient himself. We can only suppose the local form of the disease to arise from absorption, and so altering the local action of parts as to produce specific results. The constitutional form is generally an after-occurrence, although instances are known where it has not been preceded by any apparent previous form; albeit, no doubt such _has_ existed without exciting observation. Gonorrhœa shows itself without abrasion of surface; but syphilis is marked by another action—an ulceration of the solids whereon it is found.