Having put about one-third of an ounce of whole pepper in water, and it having lain about three weeks in the water, to which I had twice added some snow-water, the other water being in great part exhaled; I discerned in it with great surprise an incredible number of little animals, of divers kinds, and among the rest, some that were three or four times as long as broad; but their whole thickness did not much exceed the hair of a louse. They had a very pretty motion, often tumbling about and sideways; and when the water was let to run off from them, they turned round like a top; at first their body changed into an oval, and afterwards, when the circular motion ceased, they returned to their former length. The second sort of creatures discovered in this water, were of a perfect oval figure, and they had no less pleasing or nimble a motion than the former; and these were in far greater numbers. There was a third sort, which exceeded the two former in number, and these had tails like those I had formerly observed in rain-water. The fourth sort, which moved through the three former sorts, were incredibly small, so that I judged, that if 100 of them lay one by another, they would not equal the length of a grain of coarse sand; and according to this estimate, 1,000,000 of them could not equal the dimensions of a grain of such coarse sand. There was discovered a fifth sort, which had near the thickness of the former, but almost twice the length. In snow-water, which had been about three years in a glass bottle well stopped, I could discover no living creatures; and having poured some of it into a porcelain tea-cup, and put therein half an ounce of whole pepper, after some days I observed some animalcula, and those exceedingly small ones, whose body seemed to me twice as long as broad, but they moved very slowly, and often circularly. I observed also a vast multitude of oval-figured animalcula, to the number of 8,000 in a single drop. FOOTNOTES: [Footnote 10: From the _Transactions of the Royal Society of London_.] IX SIR ISAAC NEWTON 1642-1727 _Sir Isaac Newton, whose researches in light, gravitation, and mathematics are outstanding in the history of modern science, was born in Woolsthorpe, Lincolnshire, December 25, 1642. He was the son of an English farmer who died before Newton was born. His early education was interrupted by his mother’s poverty, but his ingenuity in making mechanical toys soon provided a means whereby he was enabled to return to school. He entered Cambridge University in 1661 and took his degree in 1665; two years later he was made a fellow of the university, and in 1669 became professor of mathematics._