The story of the prying Dutchman
Anton van Leeuwenhoek used a basic microscope to discover ‘animalcules’, and founded microbiology in the process.
ANTON VAN LEEUWENHOEK, who died in 1723, is acknowledged above all as the person who realised the extraordinary investigative power of the microscope. He is also regarded as one of the founders of microbiology and a serious contributor to crystallography, embryology and chemistry.
All up, therefore, he enjoys a reputation that would be remarkable for anyone but is especially impressive for a bloke who grew up poor, received little education, couldn’t write very well in his own language, Dutch, and not at all in the scientific lingua franca of his day, English.
Leeuwenhoek was born in Delft, in The Netherlands, in 1632, the son of a basketmaker who died six years later.
His mother, Margaretha, went on to marry a painter, Jacob Molijn. The pair afforded the boy a basic education and helped him take up a linen-draper apprenticeship at the age of 16.
Now a young man, he quickly showed himself to be resourceful and determined, completing his training and setting himself up in business. He also took on a second role as caretaker to the local sheriff, and later in life would become the region’s official inspector of weights and measures.
At the age of 40, however, he took a strong interest in the potential of the simple microscope – a device invented sometime around 1590 and already a favourite tool of scientists such as Marcello Malpighi and Robert Hooke.
Although he was not, therefore, the first to peer down a microscope, he took up its use at a time when almost anything observed through its lens was a revelation.
In his own manner Leeuwenhoek showed himself to be adept at taking very detailed notes of his findings. His first forays into microbiology – a term at that point, of course, utterly unknown – involved observing some mould, a bee sting, and a louse.
He recorded what he saw in letters that he sent to the Royal Society in London, then the uncontested centre of science in the western world. His writing had to be translated from a rough and challenging style of vernacular Dutch, but, once this was done, the English worthies were impressed not only by the detail he provided but also by his refusal to go beyond the physical evidence into the world of speculation.
His letters were published in the society’s journal, Philosophical Transactions. From there on in, Leeuwenhoek made the discovery for which he is best remembered: unicellular organisms such as protozoa and amoeba.
Again, he was not the first to notice these strange creatures, too tiny to be seen by the naked eye, but his power of description and curiosity were unmatched. He called them “little animalcules” and described them as “the most
wretched creatures I have ever seen”. After that, however, his style settled down a fit and he furnished highly detailed impressions of how protozoa moved, changed shape, and negotiated obstacles. Broadening his research, he soon found that animalcules were ubiquitous. He took great delight in finding them on his neighbour’s teeth, and perhaps less joy in discovering them in his own faeces at a time when, he noted, it was “looser than ordinary”.
And he did all this by using a simple microscope containing a single lens which, moreover, he ground himself.
In scientific and, later, more general circles, Leeuwenhoek became famous and was often visited by the rich and powerful, who were keen to hear of his work and his methods. The latter was a bit of a problem. He was a secretive man, convinced his visitors wanted to steal his precious lab equipment.
No such paranoia seems to have attended a visit by the Czar of Russia, Peter the Great, however. The scientists and the prince are reputed to have got on very well indeed, with the latter spending two hours with the former and being shown in great detail the circulatory system of an eel.
In 1680 Leeuwenhoek was invited to join the Royal Society of England, with its French counterpart following suit soon after.
From the time he took up microscopic study in middle age, his career was to last an astonishing half-century. During that time, he outlived two wives – and many of his researcher contemporaries – before dying at the ripe old age of 90.
The cause of his death was a rare condition involving the malfunction of the muscles of his diaphragm, about which he sent detailed descriptions to the Royal Society in the weeks before his demise.
These days, appropriately enough, it is known as Leeuwenhoek’s disease.