ON SYPHILIS, CONSTITUTIONAL AND HEREDITARY. CHAPTER I. THE SYPHILITIC POISON. THERE are few subjects in the entire range of the science of medicine more attractive in themselves, or more important to the general interests of mankind, than the investigation and correct appreciation of the phenomena of the animal poison termed syphilitic. Like other peculiarly contagious poisons, the syphilitic gives rise to a local and a general action, the former constituting what is known as the primary disease, the latter the secondary or constitutional disease. The physical characters of the poison are altogether unknown; but, whatever its microscopic form may be, we are aware that it is held in suspension or solution by the fluids of the body, that it is diffused through the entire mass of the blood, and probably through the solid tissues. The common mode of transmission of the poison is through the agency of a morbid secretion poured out upon the surface of a syphilitic sore. This secretion, like the fluid of the vesicle and pustule of vaccinia or smallpox, is saturated with the poison, and, on being brought into contact with the tissues of a sound person, is capable of setting up an action similar to that existing in the person from whom the poison was derived. This mode of transmission meets with an apt illustration in the simple process of vaccination: the vaccine poison is placed in a position favorable for its action upon the tissues of the patient; it there sets up a local or primary action, and that local action is accompanied, after a certain lapse of time, by a secondary or constitutional action. It has been shown by Mr. Ceely, of Aylesbury, in the instance of vaccination, that abrasion of the cuticle is by no means absolutely necessary to the success of the operation. "I have often succeeded," he says, "in procuring vaccine vesicles without puncture, on the skins of children especially, and young persons, by keeping lymph in contact with the skin, and excluding it from the air by a coating of blood. Active lymph blended with blood casually trickling down the arm, and drying in the most dependent parts, will often give rise to a vesicle." This observation bears directly on the contagion of syphilis; the poisonous secretion resting on the unbroken cuticle for a certain space of time, is absorbed with nearly the same degree of certainty as if it were introduced into the tissue of the derma by mechanical inoculation. Another condition favorable, and indeed necessary, to absorption, besides prolonged contact, is moisture. A moist condition of the lymph of vaccinia was secured, in Mr. Ceely's experiments, by the coating of blood which covered the lymph, and a similar condition must exist in the parallel case of the absorption of the poison of syphilis through an unbroken epiderma. But in the instance of syphilis, a membrane possessed of a thinner covering than the cuticle, and one in an almost con |