How did Leeuwenhoek support himself?

Leeuwenhoek went to school until he was about 14 and tried to learn the law with his uncle in Benthuizen. That apparently did not work out. Two years later, he began working and supporting himself when became apprenticed to William Davidson, a cloth merchant in Amersterdam. Back in Delft six years later, he worked as a merchant until around 1660, when he began his long career as a city official.

As an active, respected citizen of Delft who outlived almost all of his contemporaries, Leeuwenhoek was deeply involved in the life of the city. According to documents available in the Delft archives, he:

  • bought and sold property
  • made wills and pre-nuptial agreements
  • witnessed baptisms
  • was a fixture for forty years at Delft's city court
  • participated for decades in the system of excise taxation through which the city and the Republic raised most of their revenue.

However, these documents don't fully answer the question everyone has about someone who compiles an enormous body of work that took huge amounts of time staring through a tiny lens.

Where did he find the time?

Five prominent Leeuwenhoek scholars have addressed this question in print.

  •  When did he stop running his drapery business?
  •  What were his other sources of income?
  •  How much time did his civic duties take?
  •  How well off was he?
  •  How did he manage to leave such a large estate?

Dobell writes in Antony van Leeuwenhoek and his “little animals” (1932, p. 33):

It is probable that Leeuwenhoek carried on his drapery business for many years. ... Both these municipal appointments [city court and alderman] were probably sinecures, and their menial obligations performed by proxy.

Beydals writes in Twee Testamenten van Antoni van Leeuwenhoek (1933, p 1022)

Ik overtuigd ben dat Antoni van Leeuwenhoek door een voortreffelijk beheer bijdragen heeft tot den aanwas, is de grond van dit fortuin, naar ik meen, door den grootvader, den mandenmaker Thonis Phillipsz, gelegd.

I am convinced that Antoni van Leeuwenhoek through outstanding management contributing to the increase, was the basis of this fortune, I believe, laid by the grandfather, the basket maker Thonis Phillipsz.

Schierbeek writes in Antoni van Leeuwenhoek. Zijn leven en zijn werken (1951, p. 20):

Het is uiterst bezwaarlijk om zich een goed denkbeeld te vormen over de functies van een kamerbewaarder.

It is extremely difficult to form a good notion of the functions of a kamerbewaarder.

When it comes to Leeuwenhoek's duties as city inspector of wine barrels, Schierbeek notes that the city required that the work be done "selfs in persoon", by the inspector himself. Schierbeek reasons (p. 27) that "we can safely assume" that Leeuwenhoek faithfully adhered to this instruction, because otherwise he would not have needed the help that the city provided for him.

Van Seters writes in Antoni van Leeuwenhoek in Amsterdam (1951):

It must be called to mind that he bequeathed a respectable capital to his daughter Maria. This capital may in part have proceeded from bequests, but the testators -- grandfather Thonis Philips, father-in-law de Mey and his sister Maria, Leeuwenhoek's mother Grietje, and possibly his second wife Cornelia Sqalmius -- certainly do not justify the assumption that it could have been more than moderate. ...

Excellent financial managment combined with the notorious Dutch parsimony may have been concurring agents. All this may have been at work, but we may safely assume that Leeuwenhoek himself had taken a considerable active part in accumulating the means which were to render him independent and allow him to consecrate his time, from 1673 onwards, to the real aim of his life.

Roosenboom writes in Measuring The Invisible World (1959, p 19-20):

It is possible that meanwhile [by 1695] he had given up his haberdashery business and was chiefly engaged in his civic duties, having inherited some money from his mother's family. ...

It is very difficult to get a clear idea of the actual demands on L's time made by his various appointments, whether they kept him busy and whether he had to do all the work himself.

How much did he make?

The pages on Leeuwenhoek's jobs, especially that of camerbewaarder and wine gauger, give details about his income after 1660.

The five statements of payments (rekeningen) noted below show that Leeuwenhoek received a little more than 500 guilders per year from 1717 until the year before his death in 1723. He was 85 years old in 1717 and there is scant record of other city officials receiving payments until their death. Perhaps the city was honoring him in this way for his lifelong achievements and the luster he brought to the city's reputation.

Leeuwenhoek's documented income
statement date payment
in guilders
December 15, 1717 596
January 23, 1719 596
April 29, 1720 500
May 15, 1722 500
July 13, 1722 500

Even though these accountings were not timed regularly, they helped Leeuwenhoek live quite comfortably in his old age and to bequeath a substantial sum to his daughter and other relatives.

How much did he leave behind?

When Leeuwenhoek died, he left a will, but Maria was the heir and she was still living. The will was never probated. Twenty years later, when Maria died, her will was probated. As usual, that was preceded by a notary's inventory of her estate, which has survived. It sketches a very prosperous life. She had dozens of investments, mostly government bonds. She had lots of gold and silver. She had jewelry studded with diamonds. She had almost 10,000 guilders in cash in bags in her bedroom and upstairs front room.

For details, see the page below, Inventment portfolio. From the dates on the bonds, we can see that Maria did much of this herself with what van Seters calls "notorious Dutch parsimony". But she had a lot to start with when her father died. Where did it come from?