I’ve been investigating some really interesting illustrations of Antoni van Leeuwenhoek (1632-1723), who was among the first microscopists in the world and unique in achieving very high magnifications by progressively refining his hand-made single-lens microscopes.


A replica of a single-lens microscope to a design made by Leeuwenhoek (RS.8491).


He was the first person to see entities like protozoa, bacteria and spermatozoa. His illustrations were created to depict what he saw, and our modern intuition would lead us to think they simply corresponded to the observed reality, forming the precursors of modern scientific illustrations.

However, in the 17th and early 18th centuries the process of producing illustrations was very complex. If the researcher was not skilled in the visual arts, as was the case with Leeuwenhoek, he had to have artists produce the images for him. Furthermore, the published images were in engraving, but in most cases a drawing was created first and then traced onto a copper plate for subsequent engraving by an engraver, and the plate was then printed. Thus three different people were usually involved in producing one image – the researcher, the draughtsman and the engraver.

It is not always straightforward to draw or engrave a previously unseen microscopic object: there is room for interpretation of the details, and different artists resolved this issue in their own ways. Leeuwenhoek’s artists often turned to imaginative analogies, such as comparing parts of specimens to buttons, flowers or branches, as can be seen in this description of the carnous fibres in beef muscles: ‘Amongst several pieces of Flesh, where the carnous Fibres were cut transversely, I happen’d on one piece with its Branches so plain, that the Membranes and Fibres look’d like so many Boughs of Trees, with the Leaves on them, as may be seen…’ (1720). This analogy is visually expressed in the illustration produced, as the piece of flesh very clearly resembles a tree branch:


Carnous fibres, from Philosophical Transactions vol.31 p.131 (1720).


In more extreme cases, the analogies could go as far as describing – and illustrating – whole scenes rather than objects. For instance, in magnified sand granules (below) Leeuwenhoek allowed three artists working for him to depict whatever they imagined: ‘This grain of sand was wonderful, and the first to see it were three artists, all of whom looked at it with amazement; one of them, who was not the least among them, offered his services to draw such a wonderful grain of sand, and a second asked whether he might copy the drawing, so that he could show some curious persons what was to be perceived in a grain of sand. In this grain of sand, which is designated by GHIKL in Fig. 2, one might see not only, as it were, a ruined temple with some pillars, but in a corner, designated by GHI, there seemed to be two kneeling figures extending their arms towards something resembling an altar at some distance therefrom.’ (1703)


Sand granules, from Philosophical Transactions vol.24 p.1537 (1703).

The original drawing of sand granules from the Royal Society Archives (El/L3/56). The engraved pictures become inverted across the vertical axis because of the method of tracing images onto the copper plate.


The practice of making analogies between newly observed microscopic objects and elements of the long-known visible world in itself is not unique to Leeuwenhoek. Robert Hooke, the author of Micrographia (1665), used a compound-lens microscope. He drew his own images and described them using analogies, for instance likening a full stop on a paper to ‘smutty daubings on a matt or uneven floor with a blunt extinguisht brand or stick’s end’ or likening the gravel in urine to ‘Muscovie Glass, or English Sparr, to the last of which, the white plated Gravel seems most likely.’ What is striking is that the imaginative interpretations of Leeuwenhoek’s artists of the surface of sand granules are clearly visible in the illustrations: for instance, it is no big challenge to see the human-like figures in Fig. 2 even without reading the accompanying text. By contrast, Hooke’s analogies seem to bear no visible influence on his illustrations. These examples together show how artistic imagination not only aided the production of Leeuwenhoek’s illustrations of microscopic observations but also at times shaped what exactly would be drawn.

Was Leeuwenhoek satisfied with the visible presence of his artists’ interpretations, or was he eager to make them reflect what he saw and nothing more?

He himself would often compare his objects to flowers, basketwork, roots of trees and so on, and would even persuade an artist to draw with the help of an analogy, for instance by ordering him to draw a ball with a single thin string wrapped around it first to better understand the structure of a whale’s eye: ‘Then I caused the draughtsman to draw the said ball, wrapped about with a string, on the side, in order that one might understand the better the circumvolution of the fibrous parts.’ The result is shown here:


Fig4PT293_tab1 detail

Whale’s eye and a ball, from Philosophical Transactions vol.24 p.292 (1704). Fig 6 in this image is not a microscopic observation at all, but a ball with a string around it, next to the lens from a whale’s eye viewed from different angles and at different magnifications (figs 1-5).


However, in his letters Leeuwenhoek would also emphasise his reliability as an observer. He would often state that the artists depicted specimens ‘such as they saw them’, and his perception of the same specimens would be his guideline as to whether or not an artist saw and represented it adequately.

Leeuwenhoek’s letters enable us to appreciate the complexity of creating an image of something that was observed for the first time through a microscope in early modern times. Researchers and artists needed to work together closely, and the illustrations distributed in natural philosophers’ circles were at times shaped by the artists’ interpretation. Leeuwenhoek did not mind his artists’ usage of analogies, at times even suggesting his own, as long as he found the images adequate.

You can see drawings by Leeuwenhoek and Hooke, along with a replica Leeuwenhoek microscope, by coming along to our Big Draw public event this Saturday, 17 October – doors open at 11:00am.

Katya Morgunova’s research was partly supported by the AHRC-funded project, ‘Making Visible: the visual and graphic practices of the early Royal Society’.

Philosophical Transactions scans reproduced by kind permission of the Master and Fellows of Trinity College, Cambridge.



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