The secondary symptoms may be defined to be all those effects of the disease which take place subsequently to, and in consequence of, the absorption of the poison into the system: comprising sore throat, cutaneous affections—both eruptions and ulcers, pains in the bones and joints, and swellings thereon, called _nodes_. I will first consider the symptoms of primary syphilis—_chancre_ and _bubo_. The coverings and linings of the body differ according to their situation. The former, the integuments become hardened by exposure and exercise, and preserve their velvety softness where protected by clothing, and where they are subject to less use—instance the hands, feet, face, and abdomen. Certain functions are assigned to each. The covering of the feet takes on a horny hardness, and in like manner the hands of a laborer assume a glove-like protection. The abdomen, by being constantly clothed, preserves its soft texture. The lining membranes of the body have also separate offices to perform—the _serous_ and _mucous_, as they are called. The _serous_ is a name given to those lining the cavities; the _mucous_, to those having outlets. From the glans penis being generally covered by the prepuce, the parts in contact are called mucous. It differs, however, in sensitiveness, from the urethra. The entire covering also of the penis is of a very delicate and tender structure; and hence also, from sexual intercourse, these parts become the chief seat of syphilis. Gonorrhœa confines its attacks to mucous membranes, or, in other words, secreting surfaces. In fact, the matter deposited on the common and exposed skin is harmless; so also, but to a less degree, is that of syphilis. Gonorrhœa is frequently seated _on_ and _around_ the glans, and the inner surface of the prepuce; but more frequently, by a hundred fold, _within_ the urethra. The delicate surface, then, of the glans and prepuce, losing some of its sensitiveness by frequent exposure, and losing also the defence of the secretion which mucous membranes pour out, becomes accessible to an occurrence of syphilis—a disease that is readily communicable, by inoculation, to almost any part of the body. To quote Hunter, he says: “It is an invariable effect, that when any part of an animal is irritated to a certain degree, it inflames and forms matter, the intention of which is to remove the irritating cause. This has been before stated; but it is common only to secreting surfaces; and when the same cause is applied to non-secreting surfaces, ulceration is set up. This is not only the case in common irritation, but also in specific cases, as in syphilis, burns,” &c.