The discoveries that one can make with the microscope amount to very little, for one sees with the mind's eye and without the microscope the real existence of all these little beings.
Source: In Isaac Asimov's Book of Science and Nature Quotations, ed. Jason Shulman & Isaac Asimov, 1988.
-- George-Louis Leclerc de Buffon, (Sep 7 1707-1788), French naturalist; He was the first to develop a theory of geological eras and organic evolution in Histoire Naturelle, 1749-88.