But if the friends of Newton were surprised by the nature of the intelligence, they were distressed at the view which was taken of it by foreign philosophers. While one maintained that the intellectual exertions of Newton had terminated with the publication of the Principia, and that the derangement of his mind was the cause of his abandoning the sciences, others indirectly questioned the sincerity of his religious views, and ascribed to the aberration of his mind those theological pursuits which gilded his declining age. “But the fact,” says M. Biot, “of the derangement of his intellect, whatever may have been the cause of it, will explain why, after the publication of the Principia in 1687, Newton, though only forty-five years old, never more published a new work on any branch of science, but contented himself with giving to the world those which he had composed long before that epoch, confining himself to the completion of those parts which might require development. We may also remark, that even these developments appear always to be derived from experiments and observations formerly made, such as the additions to the second edition of the Principia, published in 1713, the experiments on thick plates, those on diffraction, and the chymical queries placed at the end of the Optics in 1704; for in giving an account of these experiments Newton distinctly says that they were taken from ancient manuscripts which he had formerly composed; and he adds, that though he felt the necessity of extending them, or rendering them more perfect, he was not able to resolve to do this, these matters being no longer in his way. Thus it appears that though he had recovered his health sufficiently to understand all his researches, and even in some cases to make additions to them, and useful alterations, as appears from the second edition of the Principia, for which he kept up a very active mathematical correspondence with Mr. Cotes, yet he did not wish to undertake new labours in those departments of science where he had done so much, and where he so distinctly saw what remained to be done.” Under the influence of the same opinion, M. Biot finds “it extremely probable that his dissertation on the scale of heat was written before the fire in his laboratory;” he describes Newton’s conduct about the longitude bill as “almost puerile on so solemn an occasion, and one which might lead to the strangest conclusions, particularly if we refer it to the fatal accident which Newton had suffered in 1695.”