The principal objection to inoculating in the summer months in this climate, arises from the frequency of bilious diseases at that season, to which the preparation necessary for the small-pox probably disposes the body. This caution applies more directly to children, who, at a certain age, are more subject than grown people to a disease in their bowels in warm weather.
II. The methods of communicating the small-pox by inoculation, have been different in different countries, and in the different æras of its progress towards its present stage of improvement. The scab, dossel of lint, and the thread impregnated with variolous matter, and bound up in a gash in the arm, have been laid aside.
We are indebted to Mr. Sutton for the mode of communicating it by a slight puncture with the point of a lancet, or needle, dipt in fresh matter. As it is difficult sometimes to procure matter in a fresh state, I have been led to use it with equal success by preserving it on lint in a box, and moistening it with cold water just before I used it. Matter may be kept in this way for a month, without losing its infectious quality, provided it be not exposed to heat or moisture. The former destroys its power of infecting as certainly as the salt of tartar destroys the acidity of vinegar. Moisture, by remaining long upon the matter, probably destroys its virulence, by subjecting it to fermentation. The longer matter has been kept in a general way, the longer the distance will be between the time of communicating the disease, and the eruptive fever. It will be proper always to yield to the prejudices of our patients in favour of matter taken from persons who have but few pustules. But I am persuaded from repeated observations, that the disease is no ways influenced by this circumstance. I am satisfied likewise that there is no difference between the effects of the matter, whether it be taken in its watery and purulent state. The puncture should not be larger than is sufficient to draw one drop of blood, but it should always be made by a sharp lancet, for the sudden inflammation and suppuration, excited by a dull lancet, sometimes throw off the matter, so as to prevent its infecting the body[59]. No plaster or bandage should be applied over the puncture. It should be made in the left arm of all subjects. The objections to inoculating in the leg are too obvious to be mentioned. I have heard of the disease being communicated by rubbing the dry skin with the matter. My own observations upon this subject, give me reason to suspect the facts that are contained in books relative to this mode of infecting the body. I have bound large pieces of lint dipt in fresh matter for twenty-four hours upon the arm, without producing the disease. A practitioner of physic in New-Jersey informed me, that he once gave a considerable quantity of fresh variolous matter in a dose of physic, without infecting his patient. I suspect the matter that produces the disease is of the same nature with certain poisons, which require to be brought in contact with a wound or sore in the body, before they produce their effects. I deliver this opinion with diffidence. The subject stands in need of more experiments and investigation.
III. I come now to consider the best method of preparing the body for the small-pox. This must be done, 1st, by DIET, and 2dly, by MEDICINE. The DIET should consist chiefly of vegetables. I have never seen any inconvenience from the free use of milk, as a part of the preparative diet. In some habits, where a morbid acid prevails in the stomach, we may indulge our patients in a little weak flesh broth two or three times a week with safety. A little salted meat may likewise be taken daily in such cases. Tea, coffee, and even weak chocolate, with biscuit or dry toast, may be used as usual, by persons accustomed to that kind of aliment. Wine and spirits of all kinds should be withheld from our patients, during the preparation. The more acescent their drinks are, the better. It is unnecessary that this change in the diet should take place till a day or two before the time of communicating the disease. The system accommodates to a vegetable and low diet in the course of three weeks or a month, so as to defeat in some measure the advantages we expected from it. The good effects of it appear to depend in a great degree upon the suddenness with which we oblige our patients to conform to it. For this reason, when we are called upon to inoculate persons who have lived more than three or four weeks upon a low diet, we should always direct them to live a few days upon animal food, before we communicate the disease to them. By these means we may produce all the good effects of the sudden change in the diet I have already mentioned. 2. The MEDICINES most commonly used to prepare the body for the small-pox are antimony and mercury. The latter has had the preference, and has been given in large quantities, under a notion of its being a specific antidote to the variolous matter. Many objections might be made to this opinion; I shall mention only three.
1. We often see the disease in a high degree, after the system is fully impregnated with mercury.
2. We often see the same salutary effects of mercury, when given before the disease is communicated to the body, that we perceive when it is given after inoculation; in which case we are sure the mercury cannot enter into the mixture with the variolous matter so as to destroy it.
3. If mercury acted specifically in destroying the variolous matter, it would render every other part of the preparation unnecessary: but this we know is not the case, for the neglect or improper use of the vegetable diet or cool regimen is often attended with an extraordinary number, or virulence of the small-pox, even in those cases where mercury is given in the largest quantity.
The way in which mercury prepares the body for the small-pox, seems to be by promoting the several excretions, particularly that by perspiration, which, by diminishing the quantity of the fluids, and weakening the tone of the solids, renders the system less liable to a plentiful eruption of the small-pox. But I object to the use of this medicine for the following reasons:
1. It effectually deprives us of all the benefits of the cool regimen; for mercury, we know, always disposes the system to take cold.