By a constant law of nature, the local eruption at the place of insertion breaks out at least three days before the fever; and the later the fever comes on, the milder the disorder will generally be. Hence I concluded that the cause, which immediately acted upon the whole of the animal system, was by no means the matter which had been inserted, but that which was contained in the pustules of the first eruption. I therefore thought, that if any means could be contrived to retard the action of this matter, the disorder might prove slighter, and that cold applied to these pustules might answer this purpose.
Accordingly I desired two of my patients inoculated in the hand, to hold it in cold water as often and as long as possible, from the first appearances of the local eruption to that of the fever. In both cases the fever came on; but only the sixth day after, it was hardly perceptible, and lasted but four or five hours.
I am sensible that two facts are not sufficient to establish a general rule; as other causes may have influenced the event. But by repeating and varying this experiment, useful discoveries may be made, and more attention will be paid to this topical eruption, and its relation with the general one.
Be that as it will, an inoculated patient, treated according to the foregoing rules, during the first period, will have hardly any fever in
