A man aged 44, on the sixth day after inoculation, began to complain of pains in his head and back, and of being frequently very cold. These lasted with great severity, insomuch that he took the alterative pill, a purging draught, and kept much in the air till the 9th, when about ten pustules appeared, and his complaints ceased. These seemed likely to dry away without maturating, which is not unfrequently the case where there are very few. On the 12th he took a purge; his arm remained considerably inflamed; but as he was very desirous of going to a relation’s house, where he proposed to be aired, I consented to it. On the 16th I was told he had been much indisposed since his removal, and that he wished to see me. On the 17th I visited him, and found a considerable number of pustules, to the amount of about 40, in the face, of true small-pox. The account he gave me was, that he found himself very ill on the evening after his removal, and that he perceived the pustules the next morning. This was on the 14th day from the inoculation, and the forwardness they were in agreed well with his account. His arm continued much inflamed, with many pustules near the incision. CASE XVI. A healthy young man was inoculated December the 6th, 1766. On the 11th and 12th he was cold and hot alternately, and complained of great pain in his head, back, and limbs. The 13th he was much easier, but still felt pains in his head and back. The inoculated parts, which from the operation till this day I had no opportunity of seeing, shewed evident signs of infection; but the skin at the incision was pale, not elevated, nor did a thin fluid appear under the cuticle, as is usual when the progress of infection is favourable; neither had he felt much uneasiness about the incisions, or stiffness in the axilla. 14th. He was free from all complaints; the discolouration on the arm had spread wider, and two or three pustules were discovered near the place of insertion. 15th. Many pustules appeared in different parts, about one hundred. 16th. The pustules were properly advanced, and the man seemed to be perfectly well. But there were now some appearances in the arm which I was dissatisfied with: for the inoculated part was covered with a great number of very small pale-coloured confluent pustules; and the incision, instead of being elevated, was depressed, and of a livid colour in the middle: this sometimes happens, and denotes an eschar and ulceration at the conclusion of the disease. 17th. He was seized in the middle of the day with a shivering fit, succeeded by great heat and pain in the head, back, and limbs, which continued all the following night. He likewise felt considerable pain at the incision, and in the shoulder, extending to the axilla.