In his first 22 years he learned Greek, Latin, a bit of Hebrew and assorted oriental languages. He mastered the organ and while still a child succeeded, in one week, in learning six of Euclid's mathematical treatises. He graduated with ease from Christ Church College in Oxford, became Professor of Geometry at Gresham College, and in 1662 was appointed by King Charles II to the position of Curator of Experiments in the newly created and very prestigious Royal Society. A year later Hooke was elected to the title of 'fellow', a rare honor for someone only 28 years old at the time.
In many ways Hooke was the spiritual successor of Galileo, and he championed the idea of advancing human knowledge by doing experiments in physics and astronomy. But for biologists Hooke's most important discoveries were made looking down a microscope. There, to his surprise and delight, he found a whole new living world, a world no one knew even existed, a world no human eye had ever seen before: the microscopic world of cells.
We know what Robert Hooke saw down his microscope because he published many of his findings in a book called Micrographia: or Some Physiological Descriptions of Minute Bodies made by Magnifying Glasses, with Observations and Inquiries thereupon. Most people refer to this book simply as the "Micrographia."
There are sixty chapters in this book with titles such as "Of an Ant or Pismire," "Of the curious texture of Sea-weeks," and "Of a Louse." To us, though, as we study biology, the chapter entitled "Of the Schematisme or Texture of Cork, and of the Cells and Pores of some other frothy bodies" is of the greatest significance because its contains the world's first description of cells.
To make these observations, Hooke took a sharp pen-knife, sliced a piece of cork into a very thin wafer and then
"examining it very diligently with a Microscope, me thought I would perceive it to appear a little porous."
A second specimen followed the first with growing excitement.
"I could plainly perceive it to be all perforated and porous, much like a Honey-comb in these particulars..."
The 'pores' reminded him of the small cubicles occupied by monks in a monastery, so he took the Latin word "cella" meaning a little room and gave it to what he saw. Hence the word "cell" today.
"Next in that these pores, or cells, were not very deep, but consisted of a great many little Boxes, separated out of one continued long pore, by certain Diaphragms..."
All good scientists measure, and Hooke was no exception. He began to count.
"I told (meaning counted) several lines of these pores, and found that there were usually about threescore (60) of these Cells placed end-ways in the eighteenth part of an Inch in length...and therefore in a square Inch about a Million or 1166400, and in a Cubic Inch, about twelve hundred Million, or 1259712000, a thing almost incredible, did not our Microscope assure us of it by occular demonstrations..."
Some of his excitement comes over to us in these words, which he wrote in 1665, and the sensation is a familiar one to any good scientist today. A new, amazing world, the world of cells, had been laid open to investigation.
Hooke continued his investigations and found cells in the plants of his garden and nearby fields:
"Elder, Cany, Fennel, Carrots, Daucus, Bur-docks, Teasels, Fern, some Reeds and Vegetables."
He noted that the cells of green plants were filled with juices and were separate from each other, but he was not able to take his studies much further; his microscope was too crude and he knew nothing about specimen preparation. However the new science of cell biology was definitely under way.