And even in these experiments, one pair of eyes, at least, was fixed upon Robert Boyle; eyes that saw as far as, and perhaps a little further than, even Boyle’s. Isaac Newton—the boy who had jumped against the wind in that terrific storm that raged over England when Cromwell lay dying—was only twenty-nine in 1671; but he was already professor of mathematics at Cambridge, and a Fellow of the Royal Society. It was six years since he had noticed the traditional apple fall to earth in his mother’s orchard in Lincolnshire. He himself had been tempted to seek after the philosopher’s stone; and when in 1676 Isaac Newton read in the _Transactions_ of Boyle’s “uncommon experiment about the incalescence of gold and mercury,” it was in the finest spirit, as one of Boyle’s sincerest “honourers,” that Newton wrote to Oldenburg, the secretary. He felt that “the fingers of many will itch to have the knowledge of the preparation of such a mercury; and for that end some may not be wanting to move for the publishing of it, by urging the good it may do in the world. But, in my simple judgment, the noble author, since he has thought fit to reveal himself so far, does prudently in being reserved in the rest.” Newton gave his reasons for doubting this theory of the transmutation of metals: he foreshadowed the “immense damage to the world” that might come from proceeding further with it. “I question not,” he says of Boyle’s experiments, “but that the great wisdom of the noble author will _sway him to silence_ till he shall be resolved of what consequence they may be.” It was because Boyle himself seemed “desirous of the sense of others in this point” that Newton had “been so free as to shoot my bolt.” Isaac Newton’s “bolt” took effect, though it must have cost Boyle something to give up that little bit of research; for he had been, so to speak, rolling a little ball of quicksilver and gold-dust in the palm of his hand ever since the year 1652, when he was only five-and-twenty; pressing it a little with the fingers of the other hand, till it grew “sensibly and considerably hot,” and timing the “incalescence” by a minute clock. He was to hover about the subject for a time, but in the end, he was to follow Newton’s advice. If these two men could be present at a meeting of the Royal Society in Burlington House to-day! Their two portraits are on its walls. Their two faces look down on modern experimental science. Their self-restraint has had its reward.