INTRODUCTION.

WHEN Syphilitic matter is applied to the surface of the human body, no appreciable effect in general results; but when the poison comes in contact with the thin skin in those situations where it joins the mucous membrane, or when applied to the mucous membrane itself, or to the skin in places where the epithelium has been removed, then inoculation may take place. As observed in practice, the results of inoculation afford considerable variety; when artificially performed, they are much more uniform.

Four distinct and well-marked morbid processes may follow syphilitic inoculation :

1st. The inoculated part may become affected with the "adhesive form of inflammation," in which lymph is poured out either in the substance or on the surface of the part.

2nd. The absorbents may assume an active share in the morbid process, taking up some of the infected parts, and with them portions of the syphilitic poison.

This process will, in the following pages, be called "lymphatic absorption."

3rd. The inoculated part may, within a few days of the application of the poison, be affected with suppurative inflammation; and

4th. The morbid action may terminate in mortification. Of this there are two practical subdivisions :(a) Death of the whole infected part, which is then thrown off as a slough; and

(b) Dissolution and death of a part only of the contaminated structure, leaving a part still infected.

These four kinds of morbid processes, essentially distinct when once developed, usually maintain their original character until the termination of the disease. Thus the specific adhesive inflammation may be recognized by its characteristic induration, often long after the sore (which usually accompanies it) has permanently healed. But it will, nevertheless, occasionally happen that the action will become changed, and this altered condition (if careful attention be not paid to it) will lead to an error in the diagnosis. A sore affected with adhesive inflammation, upon the application of some fresh irritant, may become a suppurating sore. The superinduced action may perhaps modify, but will not prevent, the specific results of the original disease; or again, a sore that has presented for a time the characters of the suppurative inflammation, will

alter its appearance and assume those of the adhesive form. In such a case, the first disease will not prevent the constitutional effects of the second.

Both these forms of action will constantly be accompanied by "lymphatic absorption"; and the disease in the lymphatic glands will be of the same nature as that from whence the absorbed product was derived. It will also sometimes happen that the specific adhesive inflammation may terminate in mortification, or that a part superficially mortified may become affected with specific adhesive inflammation. In either case, the mortification may be superficial or extend to the whole of the infected tissues; but if the specific adhesive inflammation has once taken place, its effects upon the constitution will subsequently appear.

The above four kinds of diseased action, resulting directly from the application of the syphilitic poison to the surface of the body, may be clearly traced both after artificial inoculation, and by attentively observing the natural course of the disease in different instances. It must always be borne in mind that the character of a sore at one time is no certain indication of what it may previously have been, or of what it may ultimately become. In the mode in which the disease is usually communicated, a part may be subjected to influences which would have a tendency to produce more than one morbid action. Such influences may

be applied either at the same or at different times. When applied at the same time, a twofold inoculation may occur on the same spot; and if the consequent respective actions require different times for their development, one disease may first run its course, and be subsequently followed by the other, which will then go through its different stages, modified perhaps, but not altered, in its essential characters, by the first.

7

LECTURE I.

THE SUPPURATING SYPHILITIC SORE.

THE various authors who have written during the present century on the subject of syphilis may be divided into three classes, according to the doctrines which they have respectively advocated. The first of these regard all the various syphilitic affections (including gonorrhoea) as depending upon the same poison. The second distinguish between syphilis and gonorrhoea, and ascribe them to the action of poisons essentially different in their nature. The third allow the difference between gonorrhoea and syphilis, but draw an equally marked distinction between the syphilis which infects a patient's constitution and that which does not. Many authors of the third class regard each of these diseases as dependent upon a separate poison, and, therefore, acknowledge three poisons as habitually producing contagious diseases of the generative organs.

The number of poisons which may produce morbid actions in a part scarcely admits of demonstration. Two different poisons may sometimes produce the same action. Thus, the secretion produced by the puncture