The contagion of syphilis, from all accounts, is a fixed principle. There is no such thing as syphilitic miasm. Neither the microscope nor chemistry has so far been able to furnish us with any more definite information regarding its nature. Some authors claim to have discovered a peculiar micro-organism which is present in the blood and the morbid lesions, and which engenders the syphilitic disease; unfortunately, however, the discovery still lacks confirmation.

The Transmissibility of Syphilis, or the Various Ways in which Syphilitic Infection may take place.

Syphilis may be transmitted either directly by contact with syphilitic tissue-elements or by procreation on the part of syphilitic parents. The manifestations of the first form are called "acquired" syphilis (syphilis acquisita), those of the latter hereditary syphilis (syphilis hereditaria). The contagion of syphilis being, as stated, a fixed principle, it begins to manifest itself at some given point, and thence infects the entire system. The infection of the system must be preceded by a solution of continuity, and it is entirely immaterial whether it is produced at the same time or some time before the syphilitic virus took effect. The uninjured epidermis, as a rule, forms a protection against infection by syphilis. In most cases the lesion and the infection take place through coitus, during which, by friction or maceration, the epidermis or the epithelial layer at some point on the genital organs is abraded, and the denuded spot on the skin or mucous membrane is readily acted on by the syphilitic virus. The virus may, however, also gain an entrance into the system through many other places-for instance, the mouth, tongue, cheeks, eyelids, forehead, nipples, fingers, etc. The transmission is either direct from a diseased to a well person, or it is indirect. The direct transmission of the syphilitic virus usually takes place during coition, kissing, wet-nursing, operations by surgeons, midwives, nurses, etc. The indirect infection may occur by utensils, cigar-holders, pipes, surgical instruments, bandages, etc. Even persons who are well may serve as agents in transporting the virus without becoming themselves affected, simply affording a temporary shelter for it at some place on their bodies-for instance,

in the vagina, or under the nails. The syphilitic contagion, under favorable circumstances, may give rise to syphilis in all persons who hitherto had not been affected with it. No age, no temperament, and, as it seems, no nation, have, as regards syphilis, any special immunity, nor again any special susceptibility. Syphilitic tissue-elements retain their powers of infection for a long but uncertain period; syphilitic papules, for instance, are capable of communicating the disease after many months.

Transmission of Syphilis by Vaccination.

The Relation of Vaccine Lymph to Syphilitic Virus.

During the early part of this century many physicians reported numerous instances in which, in consequence of vaccination, hard, protracted, indurated ulcers formed at the site of vaccination, followed subsequently by syphilitic eruptions of the skin. The question now arises, How is the transmission of syphilis, in consequence of vaccination, brought about? Our opinion is, that syphilis can only be transmitted by vaccination. when syphilitic germ-elements are transplanted at the same time with the vaccine lymph. These elements are the blood of a syphilitic person, and the molecular détritus, or the pus originating from syphilitic eruptions. We only agree in the opinion of Viennois in so far as to admit that in some cases syphilis may be transmitted by means of the vaccine lymph taken from a syphilitic person, when the vaccine virus becomes mixed with some blood from that patient. This manner of transportation also serves partially to explain the fact that, in the class of vaccinations in which blood has simultaneously been transported, only a few of the vaccinated became syphilitic. The experimental inoculations of healthy persons with the blood of syphilitics have shown that the results vary very much. Those inoculations in which some syphilitic blood was transmitted with the lymph taken from a normal vaccine vesicle correspond to those cases of vaccinal syphilis, in which a circumscribed, hard initial node formed at the place of vaccination after the vaccine vesicle had gone through the successive stages of normal development, dried into a crust, and subsequently fell off. Syphilis may, however, also be transmit

ted in vaccinating with lymph, taken from a syphilitic person, and mixed with tissue détritus resulting from syphilitic disorganization. The results of the inoculations which Pick and Krause obtained by using the matter of bullous or pustular eruptions on syphilitic persons justify us in assuming that in patients affected with latent or florid syphilis, if vaccinated with cow-pock virus, a vesicle or pustule may be produced that gradually develops into a little ulcer. Now, such a vesicle situated upon a syphilitic patient may be mistaken for a vaccine vesicle, and its contents, if used, may serve as a means of transmitting syphilis; the disease is sure to be transmitted if some of the pus it contains is used.

This view also serves to explain the fact that in some cases the vaccinations failed, and yet at about the end of the third week after the person was vaccinated a circumscribed syphilitic sclerosis of the tissues developed at the point of vaccination.

The theory that vaccine lymph in its passage through a syphilitic system likewise becomes syphilitic, i. e., acquires the property of syphilis in addition to being cow-pox, is refuted by numerous vaccinations performed upon healthy persons by some of the most reliable investigators who used vaccine lymph taken from syphilitic patients, and invariably produced normal cow-pox-never syphilis. Were the cow-pox lymph of syphilitic individuals charged with the contagion of vaccine and of syphilis, every person that is successfully vaccinated with it would also become affected with syphilis. But this does not happen.

From the preceding remarks it is evident that the following rules should be observed in performing vaccination:

(1) The child from whom the vaccine virus is taken, and his parents, should be subjected to a most careful examination.

(2) In view of the fact that congenital syphilis rarely breaks out before the end of the third week after birth, no vaccine lymph should be taken from a child under eight weeks of age. (See Hereditary Syphilis.)

(3) No vaccine lymph mixed with blood or pus should be used under any circumstances.

[The surest way of avoiding transmission of syphilis by

vaccination is to discard humanized vaccine entirely, and use animal vaccine lymph only.]

Transmissibility of Syphilis to Warm-blooded Animals.

Whether syphilis can be transmitted to animals, and produce in them manifestations similar to those produced in man, is still an open question. While some investigators—for example, Klebs and Martineau-report successful inoculations in apes and hogs, neither Neumann nor myself succeeded in producing either a primary local effect or any other manifestation of lues by inoculating this class of animals with syphilitic pus or blood. In one ape whom we inoculated in three places on the back with the pus of a soft chancre, we succeeded in producing pustules which soon became converted into ulcers that healed within three weeks. Many similar experiments furnished us equally striking proof of the difference between a soft chancre and syphilis.

First Manifestations of the Action of the Syphilitic Virus..

The first manifestation of the action of syphilitic poison is presented at the spot where the virus was deposited and absorbed. The first external manifestation that appears at the place of infection varies, however, according as the syphilitic contagion is associated with an irritative factor, i. e., pus or ichor, or with some harmless fluid, such as blood, serum, or lymph. In the former event, there appears at the place a circumscribed hyperæmia and swelling, the latter passing in a few or several days into a condition of purulent softening or ulceration of the tissues. The swelling and suppuration appear there all the more quickly and more intensely, the deeper the solution of continuity through which the syphilitic virus took effect. The tissues, in persons who had not been previously affected with syphilis, do not assume for a long while at the place of infection those pathognomonic alterations which we would recognize as evidences of luetic infection. But if the infecting contagion was not combined with pus-cells, but only with such fluids as are usually secreted on the superficial surface of the sclerotic ulcer (intercellular exudation), or with the blood of a syphilitic individual; and, above all, if at the place of infection.

there was no deep solution of continuity, but only a simple excoriation-no suppuration will take place, and the excoriation will heal quickly. After a longer or shorter period (first period of incubation), a nodule, varying in size, will form. At the junction of integument with the mucous membrane this resembles a moist papule that is just beginning to grow.

Repeated observations, however, have taught us that persons affected with latent, feeble syphilis, though having no syphilitic effects on any part of their bodies, may communicate the disease to their wives, although it is not possible to discover any initial syphilitic lesion in the latter, and have not become pregnant. In these women syphilis manifests itself by extremely rapid emaciation. In the further course of the disease they lose their hair; sometimes periosteal pains and swellings come on on some of the bones, and subsequently the menses become profuse and recur frequently. On becoming pregnant they will often abort. In what manner the syphilitic contagion, in such cases, has gained an entrance into the system, is not yet clearly known. We know just as little in what manner a woman who suffers from latent syphilis is capable of communicating the disease to her husband. Possibly, in such cases, the blood has served to transmit the infection, some bleeding erosions or excoriations having occurred on the genital organs.

In those cases in which the action of the luetic virus manifests itself in the form of an ulcer, the tissues at the base of the ulcer begin, at the end of the third or fourth week, to condense more or less markedly, or, if it is already cicatrized, the cicatrix becomes hard. If the action of the virus began in the form of a nodule, molecular disorganization will ensue a few days after it appeared. The disorganization is confined either to the upper layers, the epidermal or epithelial covering only being destroyed, and the infecting focus simulates an erosion, or the disorganization extends deeply into the nodule, and sometimes occasions a marked loss of substance. The solidification of the tissues at the base of the ulcer and the growth of the nodule are identical processes, and both of them give rise to that gradual hardness and increasing induration of