When he was grown unequal to the discharge of more active functions, and a retirement was become absolutely necessary, he took the opportunity of revising all his former writings: to this retreat therefore, and the happy protraction of so useful a life, the world is indebted for the improvements that appear in the latter editions of those works, which have already been taken notice of. It was not till now that our author could find leisure to perfect his _discourse on the small pox and measles_,[19] which had been begun by him many years before. [19] _De variolis & morbillis 1747._ As it was the principal design of these _memoirs_, to lay before the public a concise and comprehensive history of Dr. _Mead_’s writings, the occasion of this universally admired performance, cannot be better given than from the author’s own account, contained in the preface to it, in which also his connections with, and attachment to Dr. _Friend_, are further illustrated. It appears that Dr. _Mead_, from having observed in the year 1708, that some of his patients in St. _Thomas’s Hospital_, recovered from a very malignant sort of the small pox, even beyond expectation, by a looseness seizing them on the ninth or tenth day of the disease, and sometimes earlier, first took the hint to try what might be done by opening the body with a gentle purge, on the decline of the distemper; finding the success of this experiment in a great measure answerable to his wishes, he communicated this method of practice to Dr. _Friend_, and met with his approbation. The latter being, soon after, called to a consultation with two other eminent physicians, on the case of a young nobleman who lay dangerously ill of the small pox, proposed our author’s method; this was opposed till the fourteenth day from the eruption, when the case appearing desperate, they consented to give him a gentle laxative draught; which had a very good effect: Dr. _Friend_ was of opinion to repeat it, but was over-ruled, and the patient died the seventh day after.[20] [20] Friendi opera, p. 263.