This section is from the book "Health", by W. H. Coefield.
It is rarely that people have smallpox more than once ; but yet there are not a few cases on record where the same person has had it twice, and a certain number three times, and even more, so that it is at any rate possible to have it more than once; and when a person has it twice, very frequently it is worse the second time ;than the first time, and not unfrequently he dies of it; so that we may fairly conclude that persons who have it twice, or three times, are persons who, for some reason or another, have a natural susceptibility to this particular disease.
Now, the first thing that was done with the view of diminishing the mortality from smallpox was a most extraordinary one. Where it was found out nobody knows. No doubt it was in the regions from which smallpox came, viz., from the East. Smallpox came from Asia. It was found in Europe in the sixth century after Christ, brought by the Saracens ; and it was taken from Europe to America by the Spaniards. It was found that if a person were inoculated with the poison of smallpox he was not so likely to die as he was if he caught the disease in the ordinary way, and inoculation was practised, nobody knows how long, in various parts of Asia. It was introduced into Constantinople in 1673, and from there it was brought to notice in England in 1717 by Lady Wortley Montague. She writes, "Every year thousands undergo this operation, and the French Ambassador pleasantly says that they take the smallpox here by way of diversion, as they take waters in other countries."
The practice of inoculating people with the poison of smallpox was tried under the sanction of the Eoyal Society upon six condemned criminals. I mention this because it shows that in 1717 they had the good sense to make criminals useful I must confess that if I were a condemned criminal I would rather die of poison than be hanged. It is curious to notice the steps they took; they first tried it upon these criminals, " next five pauper children of St James's; then the children of a few families of distinction ; and, to crown all, their Majesties, acting on the cautious advice of Sir Hans Sloane, had all the royal children submitted to the operation." (Dr. Guy.)
I submit that that is a most extraordinary fact that they should take the poison of the most abominable disease that the world has ever seen and inoculate people of all classes of society up to the Royal families of Europe with it Now what can that mean ? There is no way of getting out of it except this, that the disease was so widely spread that, practically speaking, the whole population were certain to take it; and it shows us that it was not worth while to run the chance of not getting it. What would anybody say if I were to propose now to inoculate people with scarlet fever; they would say that it was a monstrous proposition, and why ? because the whole population is not obliged to have scarlet fever, it does not disfigure people, it does not cause so many deaths as smallpox did ; the only way we can account for inoculation being practised is that the whole population were so imbued with the dread of smallpox that they would rather do anything than run the risk of catching it, otherwise it is the last thing you would expect anybody to do-to inoculate themselves and their children with the poison of such a terrible disease.
There is no manner of doubt whatever that the liability to die from the disease was much less when it was inoculated than when it was got in the ordinary way, and you can partly understand this by the following considerations : If you catch a disease it is quite clear you are in a state in which you are fit to take it, but if you are deliberately given the disease you run the chance that you are not in a condition in which you would catch it, and so you run the chance of being given the disease when you are best able to withstand it. And whereas natural smallpox killed one in every five, inoculated smallpox killed but one in every fifty at first, and afterwards only one in five hundred, when they knew the proper precautions to take. So that the peiv son inoculated was much less likely to die from it. But, on the other hand, he became a centre of infection, because he had the disease, and other people could take it from him ; so the centres of infection being multiplied, the number of epidemics during the period when inoculation was practised was greater than before ; but whether the actual mortality was greater or less during the inoculation period is a matter of disputa Dr. Guy decides that the mortality was less, and that inoculation, in spite of spreading the number of centres of infection, actually lessened the number of deaths from the disease. Some other writers are of opinion that the number of deaths during the inoculation period was greater in proportion than the number of deaths before, and that inoculation of smallpox was a danger to the community.
Inoculation with smallpox is now illegal, and rightly so, for this reason : If you or I choose to be inoculated with smallpox we have no right to expose other people to the chance of catching it.
A somewhat similar disease to smallpox affects other animals than man; there is a disease among cows called the cow-pox, one among horses called the horse-pox, and one among sheep known as the sheep-pox. Now, at the end of the last century, there was a prevalent belief among the peasants in Gloucestershire that people who had had the cow-pox could not catch smallpox, and they were not afraid of it: no doubt many persons heard this, but it required a man to turn that fact to advantage. That man was found in an English medical practitioner named Jenner, who seized upon the idea prevalent among these peasants, and in 1795 began some experiments, of which, in 1798, he published the results. He tried inoculating persons with matter from one of the vesicles of a cow or calf attacked with cow-pox, and he made some very conclusive experiments of which people are not generally aware. He inoculated persons who had had the cow-pox (dairymaids and others), and persons who had been vaccinated, with smallpox virus, in some instances more than once, and found that they were not capable of taking smallpox even when the poison was put into their blood.