More difficult than the selection of subjects is the selection of virus for the rite; and the manifold dangers and the requisite precautions were thus specified—
Especially as regards the quality of vaccine lymph, the careless or uneducated vaccinator is using a dangerous weapon. It is only during part of the course of a vaccine vesicle that its lymph is suitable for further vaccinations: for after a given moment, at which the contents of the vesicle possess their maximum of simple contagiousness, they tend more and more toward the quality of common inflammatory products; and matter now taken from the vesicle is no longer the simple agent of a specific infection, but has less efficiency for its real purpose, and is specially able to produce other undesired results.
A danger of somewhat similar kind is that of taking lymph from vesicles which already have been accidentally ruptured, or where from any other cause, local or constitutional, their specific fluid is likely to have been modified by common irritative processes.
The danger of taking matter from irritated vesicles, and from vesicles at too advanced a period of their course, is one which circumstances render frequent; and there is reason to believe that, in at least a very large proportion of those cases where abnormal effects have resulted from so-called vaccination, it has been the employment of this ambiguous irritative matter which has occasioned the mischief and scandal.
Still more critical changes occur in lymph when removed from the body, unless appropriate means be taken to preserve it; for, under the influence of air and moisture, it tends, like other dead organic matter, to putrid decomposition; and inoculation with it, when thus changing, can hardly be more useful or less dangerous than a casual scratch inflicted in the dissecting room. (P. lxii.)
No one who considers this limitation of vaccination to the healthy, and these prescriptions as to the collection and exhibition of “lymph,” can fail to see that the charges of injury and death brought against the common practice were allowed and accounted for—were, indeed, the unavoidable associates of that practice. Vaccination, as described by Simon, was an ideal operation—impracticable on any ordinary terms. His contention and his approbation were reserved for “properly-performed vaccination” on a healthy child, with innocuous virus, the proof of each condition being discovered in the result. If unsatisfactory or injurious, or deadly, then the vaccination could not have been “properly performed”—either the child was unhealthy, or the virus was at fault.
Nor can we wonder that the people, having experience of the uselessness and misery of the virulent practice should, undismayed by the terror of smallpox, decline its observance; nor that those who made gain thereby should, distrusting their power to prevail by reason, invoke legislation to enforce the imposture, calling in the policeman to support the doctor, as of old the soldier supported the priest.
Still further to sustain his case, Simon addressed the following Circular of Questions to upwards of 500 medical men—
I.—Have you any doubt that successful Vaccination confers on persons subject to its influence a very large exemption from attacks of Smallpox, and almost absolute security against death by that disease?
II.—Have you any reason to believe or suspect that vaccinated persons, in being rendered less susceptible of Smallpox, become more susceptible of any other infective disease, or of phthisis; or that their health is in any other way disadvantageously affected?