No illustrations were made of the Royal Society's Leeuwenhoek microscopes until 1753 and Mayall reports that even then "they do not give a clear idea of the construction of the instruments".(2) As one of the earliest 'microscopists', Leeuwenhoek was seen as a heroic figure and there was a history of speculation into how he was able to achieve his magnifications with such seemingly basic microscopes.
Mayall writes that "the general impression during his [Leeuwenhoek's] lifetime seems to have been that he utilized lenses consisting of spherules of blown glass", and that it was Henry Baker who in 1740 discovered that "the magnifiers were not spherules of blown-glass, but bi-convex lenses".(3)
Mayall is critical of Folkes' earlier report and claims it to have been done "somewhat vaguely" and appeared "not to have directed his attention minutely to their construction". Interestingly he misses that it was Folkes, not Baker, that first noticed Leeuwenhoek's lenses were bi-convex:
"For the construction of these Instruments, it is the same in them all, and the Apparatus is very simple and convenient: They are all single Microscopes, consisting each of a very small double Convex-Glass." (4)
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References
- J. Mayall, 'Leeuwenhoek's microscopes', Journal of the Royal Microscopical Society, series II vol. VI (1886), 1047-1049, p. 1048.
- Same reference as above, p. 1048.
- Same reference as above, p. 1047.
- M. Folkes, 'Some account of Mr. Leewenhoek's curious microscopes lately presented to the Royal Society', Philosophical Transactions, Vol. 32 (1723), 446-453, p. 449.
James Hyslop
James Hyslop, 'John Mayall and reproductions of early microscopes', Explore Whipple Collections, Whipple Museum of the History of Science, University of Cambridge, 2008