Microscopy

Beginnings

The first microscope was invented about 1610.

Micrographia

Title Page of Hooke's Micrographia

Micrographia appeared in 1665, sponsored by the Royal Society. It was an advantage that Hooke was a skilled artist. It was the Royal Society's second publication, after John Evelyn's Sylva, or Discourse on Forest Trees.

The hand-crafted, leather and gold-tooled microscope he used to make the observations for Micrographia was originally constructed by Christopher White in London. It is now on display at the National Museum of Health and Medicine in Washington, DC.

Details

Cork divided into what reminded him of monks' cells.

One of the observations in Micrographia was of fossil wood, the microscopic structure of which he compared to ordinary wood. This led him to conclude that fossilized objects like petrified wood and fossil shells, such as Ammonites, were the remains of living things that had been soaked in petrifying water laden with minerals. Hooke believed that such fossils provided reliable clues to the past history of life on Earth, and, despite the objections of contemporary naturalists like John Ray who found the concept of extinction theologically unacceptable, that in some cases they might represent species that had become extinct through some geological disaster.

Micrographia also contains Hooke's ideas on combustion. Hooke's experiments led him to conclude that combustion involves a substance that is mixed with air, a statement with which modern scientists would agree, but that was not widely understood, if at all, in the seventeenth century. Hooke went on to conclude that respiration also involves a specific component of the air. Partington even goes so far as to claim that if "Hooke had continued his experiments on combustion it is probable that he would have discovered oxygen".

Diagram of cork from Hooke's Micrographia Diagram of Moon from Hooke's Micrographia

Micrographia from Google Books

Richard Reeve