image EL_L3_64_Fig
Image number: RS.15801
Credit: ©The Royal Society

Observations of lens (crystalline humour) of a whale


22 July 1704


Unknown, Artist

Object type

Archive reference number

Manuscript page number




height (page): 165mm
width (page): 150mm



Six images in a letter by Antoni van Leeuwenhoek to the Royal Society. The verso side of the paper is entirely covered in red chalk, most likely for the copying of the images. Leeuwenhoek had these drawings made by a draftsman.

Leeuwenhoek received two crystalline humours (or lenses) of two different whales through Mr Frederik Wolfert van Overschie (1655-1727), a town mayor of Delft, who had received the lenses from a commander on a Greenland mission. Leeuwenhhoek also had one more lens from a labourer who brought the lens to him saying that he had received it from a friend who just returned from whaling.

Fig. 1: the real size of the crystalline humour as he had received it.
Fig. 2: CDEF shows a small part of the crystalline humour of a whale, taken from a spherical body having the size designated by GH in fig. 3. It shows the extremely thin fibres that Leeuwenhoek called fibrous matter.
Fig. 3: the size of the second crystalline humour.
Fig. 4: the real size of CDEF in fig. 2, is like IK in fig. 4.
Fig. 5: a sphere of the crystalline humour of a whale.
Fig. 6: the sphere from another angle.

Both figs 5 and 6 actually depict a leader ball which Leeuwenhoek had wrapped with a single string just as he had observed the fibrous matter in the lens of the whale, so that he could let his draftsman draw it.

Object history

The Journal Book mentions on 25 October 1704, 'A Letter was Read from Mr Leeuwenhoeck concerning the Chrystalline Humor in a Whales Eye' (JBO/11/55).

Printed in A. Leeuwenhoek, ‘Concerning the Flesh of Whales, Crystaline Humour of the Eye of Whales, Fish, and Other Creatures, and of the Use of the Eye-Lids’, Phil. Trans. vol. 24, no. 293 (September and October 1704), pp. 1723-30, tab. 1, figs 1-6 (reference to 'painter' at p. 1726).

Related Fellows

Antoni van Leeuwenhoek (1632-1723, Dutch), Naturalist

Associated place

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