Micrographia is an early work on microscopy by the English scientist Robert Hooke, published in 1665. It contains a wide range of Hooke's observations on a variety of subjects, including insects, plants, and organic material. Hooke also included many detailed hand-drawn diagrams of his observations. Micrographia was a groundbreaking work in the field of microscopy and helped to establish the microscope as a valuable tool for scientific research. It is considered to be one of the most important works in the history of science.