-
Hans and Zacharias Janssen
This father and son duo produced the first compound microscope. It was made by combining two convex lenses within a tube. The two discovered the microscope by putting several lenses in a tube. They noticed an object near the tube was greatly enlarged, much larger than any simple magnifying glass could achieve by itself. -
Period: to
Cell Theory
-
Robert Hooke
Robert Hooke first applied the word "cell" to describe the basic unit of life. He looked at the cells in thin slices of cork, this is how he discovered plant cells. He also reported seeing similar structures in wood and in other plants. Hooke discovered these cells through his technological efforts of creating a microscope with 50x magnification. -
Anton van Leeuwenhoek's First Discovery
Leeuwenhoek used his knowledge of grinding lenses to achieve greater magnification of lenses. He then utilized this to make a microscope. The microscope was much simpiler than the ones used in that time period. This microscope enabled Leeuwenhoek to make detailed observations of bacteria. -
Anton van Leeuwenhoek's Second Discovery
Leeuwenhoek was the first to observe and describe single celled organisms. These were origionally called amimalcules by himself. His observations were accepted by the Royal Society of London after much skeptisism. Later, it was found out that these single celled organisms were really called protozoa and were discovered by Leewenhoek when he was examining his saliva. -
Anton van Leewenhoek's Third Discovery
In addition to single celled organisms, he was also the first to record other things. These were muscle fibres, spermatozoa, and blood flow in capillaries. He made these discoveries using his own microscopes. He also made drawings of the things he saw in his microscope. -
Matthias Schleiden
Schleiden discovered that all plants are made up of cells by observing the structures of plants. He recognized the importance of the cell's nucleus. He stated that the different parts of a plant are all made up of cells. He knew the nucleus was important to cell division but had the wrong idea of how cell division happened. -
Theodor Schwann
Schwann discovered that all animals are composed of cells. He demonstrated that every mature animal tissue is composed of embryonic cells. Also when working with animal tissue, Schwann discovered pepsin which is the first digestive enzyme prepared from animal tissue. He also experimented to disprove the idea of spontaneous generation of cells. -
Rudolf Virchow
Virchow stated that all living things come from other living things. He was doing experiments with diseases when he found out that all cells come from pre existing cells. He proved that the previous theory about spontaneous generation was false. His theory is now widely accepted into the Cell Theory.
