These theories are only alluded to by way of elucidation of the statement that belief in one or the other of them has an important bearing on the relation of syphilis to marriage, and because, whichever is thought to be the most plausible, they equally lessen or altogether do away with a certain proportion of the danger formerly thought to surround the marriage of a syphilitic even after a most protracted interval. It is not necessary to accept either the one or the other implicitly. The essential point is the recognition of the fact that modern syphilographers, as a rule, regard the tertiary or late symptoms as indicative of damage done during the active period—as relapses or sequelæ, and not as fresh outbreaks, of a highly contagious and transmissible disease. Their time of appearance, their entire want of symmetry, their non-contagiousness, their non-inoculability, all favor this view, and we may now see what evidence corroborative of it may be obtained from clinical facts.
It will be necessary, in the first place, to admit that there seems to be but little doubt in the minds of most syphilographers that in rare instances syphilitic children have been born to parents who had long passed the limits of the secondary period. At least the great majority of writers upon this subject speak confidently of the exceptional occurrence of such cases, and assert that syphilis may be transmitted during any of its stages.6 If, however, we come to look for positive evidence in this respect, we will find very little that is entirely satisfactory. Cases are reported, to be sure, in which eight, ten, twelve, or even fifteen or twenty, years after the primary sore, syphilitic patients have become the parents of children who showed unmistakable indications of the disease. When we examine the history of the cases, we find usually that many important points are omitted without which it is impossible to be certain of its true character. Were both parents originally infected? If not, has a recent case of syphilis occurred in the one who at first escaped? If they were both diseased originally, has either been subsequently re-infected?—a much more frequent accident than has been commonly supposed.7 On applying these tests to the cases in question it will be found that few if any of them are thoroughly convincing. Kassowitz's observations,8 made, it must be remembered, upon persons with whom no mercurial treatment had been employed, seemed to show that the average limit of transmissibility was about ten years, after which time healthy children began to be born. His observations were, however, incomplete in many respects, and, like all such investigations, are of course open to the suspicion of intentional deception on the part of the patients.9 Even these cases, however, show unequivocally, as do all which have ever been recorded, the steady diminution of the transmissive power under the influence of time alone.
6 Belhomme et Martin, Traité de la Syphilis, p. 413.
7 Cornil, op. cit., p. 20.
8 Die Vererbung der Syphilis, Wien, 1876.
9 See also Hutchinson, British and Foreign Med.-Chir. Rev., Oct., 1877.
I have said that the majority of writers seem to have no doubt of the long continuance of this transmissive power in rare cases. There are, however, a few notable exceptions. Fournier, whose immense experience and acuteness of observation entitle his opinion to the utmost consideration, says that in cases of paternal heredity the duration of the force of transmission never exceeds at the maximum three or four years.10 In no case of the many hundreds he has observed has he known a syphilitic father to infect a child—the mother being healthy—at a later period than the one mentioned. And he is equally positive that the gradual diminution and final extinction of the syphilitic reaction of the parents upon the children is a veritable pathological law, "absolutely demonstrated."11
10 Syphilis and Marriage, Am. ed., p. 87.
11 Op. cit., p. 88. Of course when both parents are diseased a somewhat longer period of activity is to be expected for the poison.
M. Mireur, a careful and accurate observer, records12 a striking instance in which in the history of a couple, both syphilitic and untreated, eight pregnancies occurred. The first resulted in abortion at fifth month; the second, in abortion at seventh month; the third, in a stillbirth; the fourth, a syphilitic child dying in one month; the fifth, in a syphilitic child dying in forty-five days; the sixth, seventh, and eighth, in living, healthy children. To me the most interesting fact in the whole relation is that during a portion of the time, and immediately after the last three pregnancies, which resulted in the birth of healthy children, both husband and wife manifested grave tertiary syphilitic symptoms—gummata, tubercles, ulcers, etc. This is direct evidence of the strongest kind in favor of the view that syphilis ceases to be transmissible by heredity at the end of a certain period, as we know that it ceases to be contagious or inoculable.