That on one out of the four places on the arms, in which the infection had been inserted in the inoculation, there was found adhering a small dry scab. That the throat was perfectly free from any pustulary appearance; and that all the viscera were quite sound, and shewed no sign of any disease, either external or internal. But that on opening the skull, there were, in the lower and back part of the head, four ounces of extravasated water or serum, except which, nothing deviated from a healthy and natural state. Query. Was the disease above described, the natural small-pox? The effect of any variolous matter left in the blood, in consequence of the previous inoculation? Or, were the pustulary eruptions, which shewed themselves on the 12th day of the disease, a critical discharge of a putrid or other kind of fever? London, April 11, 1775. SIR, I have carefully perused the case you have communicated to me, and am of opinion, that the disease you have described was not the small-pox. The cold fit which preceded the other complaints, is what usually happens at the commencement of the small-pox in common with other fevers; with this exception, I do not find one symptom during the whole illness, that corresponds with the well known progress of that disease. The eruptions (on which I presume the suspicion of the small-pox was founded) differed from that distemper in every essential point, viz. The time and manner of their appearance; the parts they occupied; and their form and progress. Neither am I of opinion that the disease was the effect of any variolous matter left in the blood, in consequence of the previous inoculation. That the natural and inoculated small-pox, as well as other diseases which form critical discharges on the skin, may sometimes be succeeded by boils or breakings out, is well known; but these follow very soon, are free from danger, and easily cured by gentle purges. Now in the case before me, I find the patient passed through the inoculated disease, in a regular, complete, and satisfactory manner, and continued well for six weeks after, making no complaint: after which he was seized with a disease that I have not the least doubt was a fever of the putrid kind; but I do not think that the pustulary eruptions can with propriety be deemed critical, as they did not terminate the disease; I rather esteem them to have been marks or tokens of great malignity and danger. In the course of my whole practice, which it is well known has been extensive, I never knew a single instance of any one having the natural small-pox, after having been inoculated; nor have I ever known any person to have the disease a second time in the natural way. I shall not pretend to decide on what may have happened to others; but what I have said is true, so far as relates to my own experience. The report of the gentlemen who opened the body, affords no material information.