Hooke, Leeuwenhoek and ‘exceedingly small creatures’ . . .
One of the earliest passages in the Hooke folio records the Society’s receipt of a letter from Dutch microscopist Anton van Leeuwenhoek (1632-1723) describing his observation of what he termed ‘animalcules’ in water together with a number of testimonials attesting to the truth of his discovery.
The ‘animalcules’ he describes are in fact the earliest observations of protozoa. Protozoa are animal-like, single-celled organisms most commonly found in water and very rarely visible without the use of a microscope.
Leeuwenhoek’s observations prompted Hooke to conduct a series of experiments during Royal Society meetings in an attempt to see the ‘exceedingly small animals’ which Leeuwenhoek described. His initial experiment which observed pump water through a single microscope at a meeting on the 1st November 1677, met with little success and he decided to use pepper water in his next experiment. Unfortunately this did not work either. At the meeting of the 15th November 1677, Hooke finally sees ‘exceedingly small animals’ in rain water with a small amount of black pepper added to it and by the 6th December 1677, Hooke had refined the microscope sufficiently that ‘the small insects’ appear ‘much more magnified and clear’.
The Hooke Folio is particularly useful in charting the development of Hooke’s experiments to view protozoa because the records held by the Society (prior to the rediscovery of the Folio) break off abruptly part way through describing Hooke’s experiment on 15th November 1677 and do not recommence until the 6th December 1677. The Folio pages, missing from the official records, describe, amongst a number of other things, how Hooke modified the microscope so that the ‘animals’ could be seen more clearly and a debate amongst the fellows about how the ‘animals’ might be generated in the water and whether pepper somehow influences this generation.
This interest in protozoa is evident throughout the Folio, in fact some of the last pages of the Folio from 1691 record Mr Henshaw’s observations of ‘animals’ in pepper water.
Comments :
[…] Circulating blood, exchanging ideas On a recent visit to the excellent Boerhaave Museum in Leiden I noticed several of the Royal Society’s members represented among its collection. For example, on display was a copy of John Flamsteed’s beautiful Atlas coelestis, published posthumously in 1729 by his wife and amanuensis Margaret. Most prominent, however, was the work of Antoni van Leeuwenhoek, who is credited, along with Robert Hooke with the discovery of micro-organisms, a process which, as Jenni noted in her earlier post, can be traced more clearly using the Hooke folio. Leeuwenhoek was elected a member of the Royal Society in 1680 and clearly relished this recognition of his achievements: a 1686 portrait by J. Verkolje shows the former shopkeeper leaning proudly on a copy of the Society’s charter. One of Leeuwenhoek’s letters, published in the Philosophical Transactions of 1708/9, discusses the circulation of blood in fishes, a topic on which he had first corresponded with the Society in 1688. His observations and sketches decisively proved the theory that had been first advanced by William Harvey in 1628. Leeuwenhoek’s finding was illustrated by an incredibly detailed drawing of the circulation in the tail of a tadpole in the Boerhaave Museum. […]
What became of the figure on this Page? I would dearly love to have a copy of the original letter and drawings that are mentioned.
Hi Mark, do you mean the letter from Leeuwenhoek that was translated in Phil Trans in 1708/9? Like most of Leeuwenhoek’s correspondence the original is in the ‘Early Letters’ books in the Royal Society archive. The particular one that I mentioned is in EL/L4/22. Several of these are illustrated with red chalk drawings which are reproduced for those that are printed in Phil Trans. The illustration I saw in the Boerhaave Museum was made in Delft in 1688 and was labeled ‘the true circulation of the blood’ reference no. 1204b. I have only got a fairly poor picture of this through some glass unfortunately!
I am a professor of Microscopy in the Universidad Nacional Autónoma de México and I works in a Electrón Microscopy Laboratory. I would like to have a copy of the short video from Professor Lisa Jardine about “Rediscovering Robert Hooke”. How is posible obtain this video. Thank you for uour attention at this mail.
Biol. Armando Zepeda Rodriguez.
Adress:
Facultad de Medicina. UNAM.
Departamento de Biologia Celular y Tisular.
Circuito Interior. Edificio A 3er piso.
Laboratorio de Microscopía Electronica.
México, D.F. 04510
Cooyoacan.
MEXICO.