Biography of Robert Hooke, the Man Who Discovered Cells

Drawing of a flea

Robert Hooke/Wikimedia Commons/Public domain

Robert Hooke (July 18, 1635–March 3, 1703) was a 17th-century "natural philosopher"—an early scientist—noted for a variety of observations of the natural world. But perhaps his most notable discovery came in 1665 when he looked at a sliver of cork through a microscope lens and discovered cells.

Fast Facts: Robert Hooke

  • Known For: Experiments with a microscope, including the discovery of cells, and coining of the term
  • Born: July 18, 1635 in Freshwater, the Isle of Wight, England
  • Parents: John Hooke, vicar of Freshwater and his second wife Cecily Gyles
  • Died: March 3, 1703 in London
  • Education: Westminster in London, and Christ Church at Oxford, as a laboratory assistant of Robert Boyle
  • Published Works: Micrographia: or some Physiological Descriptions of Minute Bodies made by Magnifying Glasses with Observations and Inquiries Thereupon

Early Life

Robert Hooke was born July 18, 1635, in Freshwater on the Isle of Wight off the southern coast of England, the son of the vicar of Freshwater John Hooke and his second wife Cecily Gates. His health was delicate as a child, so Robert was kept at home until after his father died. In 1648, when Hooke was 13, he went to London and was first apprenticed to painter Peter Lely and proved fairly good at the art, but he left because the fumes affected him. He enrolled at Westminster School in London, where he received a solid academic education including Latin, Greek, and Hebrew, and also gained training as an instrument maker.

He later went on to Oxford and, as a product of Westminster, entered Christ Church college, where he became the friend and laboratory assistant of Robert Boyle, best known for his natural law of gases known as Boyle's Law. Hooke invented a wide range of things at Christ Church, including a balance spring for watches, but he published few of them. He did publish a tract on capillary attraction in 1661, and it was that treatise the brought him to the attention of the Royal Society for Promoting Natural History, founded just a year earlier.

The Royal Society

The Royal Society for Promoting Natural History (or Royal Society) was founded in November 1660 as a group of like-minded scholars. It was not associated with a particular university but rather funded under the patronage of the British king Charles II. Members during Hooke's day included Boyle, the architect Christopher Wren, and the natural philosophers John Wilkins and Isaac Newton; today, it boasts 1,600 fellows from around the world.

In 1662, the Royal Society offered Hooke the initially unpaid curator position, to furnish the society with three or four experiments each week—they promised to pay him as soon as the society had the money. Hooke did eventually get paid for the curatorship, and when he was named a professor of geometry, he gained housing at Gresham college. Hooke remained in those positions for the rest of his life; they offered him the opportunity to research whatever interested him.

Observations and Discoveries

Hooke was, like many of the members of the Royal Society, wide-reaching in his interests. Fascinated by seafaring and navigation, Hooke invented a depth sounder and water sampler. In September 1663, he began keeping daily weather records, hoping that would lead to reasonable weather predictions. He invented or improved all five basic meteorological instruments (the barometer, thermometer, hydroscope, rain gauge, and wind gauge), and developed and printed a form to record weather data.

Some 40 years before Hooke joined the Royal Society, Galileo had invented the microscope (called an occhiolino at the time, or "wink" in Italian); as curator, Hooke bought a commercial version and began an extremely wide and varying amount of research with it, looking at plants, molds, sand, and fleas. Among his discoveries were fossil shells in sand (now recognized as foraminifera), spores in mold, and the bloodsucking practices of mosquitoes and lice.

Discovery of the Cell

Hooke is best known today for his identification of the cellular structure of plants. When he looked at a sliver of cork through his microscope, he noticed some "pores" or "cells" in it. Hooke believed the cells had served as containers for the "noble juices" or "fibrous threads" of the once-living cork tree. He thought these cells existed only in plants, since he and his scientific contemporaries had observed the structures only in plant material.

Nine months of experiments and observations are recorded in his 1665 book "Micrographia: or some Physiological Descriptions of Minute Bodies made by Magnifying Glasses with Observations and Inquiries Thereupon," the first book describing observations made through a microscope. It featured many drawings, some of which have been attributed to Christopher Wren, such as that of a detailed flea observed through the microscope. Hooke was the first person to use the word "cell" to identify microscopic structures when he was describing cork.

His other observations and discoveries include:

  • Hooke's Law: A law of elasticity for solid bodies, which described how tension increases and decreases in a spring coil
  • Various observations on the nature of gravity, as well as heavenly bodies such as comets and planets
  • The nature of fossilization, and its implications for biological history

Death and Legacy

Hooke was a brilliant scientist, a pious Christian, and a difficult and impatient man. What kept him from true success was a lack of interest in mathematics. Many of his ideas inspired and were completed by others in and outside of the Royal Society, such as the Dutch pioneer microbiologist Antoni van Leeuwenhoek (1632–1723), navigator and geographer William Dampier (1652–1715), geologist Niels Stenson (better known as Steno, 1638–1686), and Hooke's personal nemesis, Isaac Newton (1642–1727). When the Royal Society published Newton's "Principia" in 1686, Hooke accused him of plagiarism, a situation so profoundly affecting Newton that he put off publishing "Optics" until after Hooke was dead.

Hooke kept a diary in which he discussed his infirmities, which were many, but although it doesn't have literary merit like Samuel Pepys', it also describes many details of daily life in London after the Great Fire. He died, suffering from scurvy and other unnamed and unknown illnesses, on March 3, 1703. He neither married nor had children.

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