In the year 1722, when he had reached the eightieth year of his age, he was seized with an incontinence of urine, which was ascribed to stone in the bladder, and was considered incurable. By means of a strict regimen, however, and other precautions, he was enabled to alleviate his complaint, and to procure long intervals of ease. At this time he gave up the use of his carriage, and always went out in a chair. He declined all invitations to dinner, and at his own house he had only small parties. In his diet he was extremely temperate. Though he took a little butcher meat, yet the principal articles of his food were broth, vegetables, and fruit, of which he always ate very heartily. In spite of all his precautions, however, he experienced a return of his old complaint, and in August, 1724, he passed a stone the size of a pea, which came away in two pieces, the one at the distance of two days from the other. After some months of tolerable good health, he was seized in January, 1725, with a violent cough and inflammation of the lungs; and in consequence of this attack, he was prevailed upon, with some difficulty, to take up his residence at Kensington, where his health experienced a decided improvement. In February, 1725, he was attacked in both his feet with a fit of the gout, of which he had received a slight warning a few years before, and the effect of this new complaint was to produce a great and beneficial change in his general health. On Sunday the 7th March, when his head was clearer and his memory stronger than Mr. Conduit had known it to be for some time, he entered into a long conversation on various subjects in astronomy. He explained to Mr. Conduit how comets might be formed out of the light of vapours discharged from the sun and the fixed stars as the centres of systems. He conceived that these luminaries were replenished by the same comets being again returned to them; and upon this principle he explained the extraordinary lights which were seen among the fixed stars by Hipparchus, Tycho Brahe, and Kepler’s disciples, and which he supposed to arise from the additional fuel which they received.[122] Notwithstanding the improvement which his health had experienced, his indisposition was still sufficiently severe to unfit him for the discharge of his duties at the mint; and as his old deputy was confined with the dropsy, he was desirous in 1725 of resigning his office to Mr. Conduit. Difficulties probably were experienced in making this arrangement, but his nephew discharged for him all the duties of his office; and during the last year of his life he hardly ever went to the mint.