Cornelis Isaaks 's Gravesande

Gravesande was a medical doctor who attended the University of Leiden beginning in 1651 while Leeuwenhoek, a year younger, was apprenticing in Amsterdam. Gravesande got his medical degree in Angiers, in France, in 1655, the same year that Leeuwenhoek bought his house on the Hippolytusbuurt.

Gravesande's father Isaac Arents (died 1655) was a headman of the St. Nicolaas guild and a grocer on the Choorstraat, corner of the Papenstraat. His uncle Cornelis Arents (died 1649) owned the house on the corner of the Hippolytusbuurt and Nieuwstraat next door to the one that Leeuwenhoek bought in 1655. His cousin Franco (Cornelis Arents's son) continued in the house as a grocer until his death in 1665.

After his marriage to Sara Ipelaer (1639-1659) in February 1658, Gravesande moved to her house on the east side of the Hippolytusbuurt, second house from the corner of the Choorstraat. Sara was buried on 12 February 1659, about a month after the birth of their son Isaac, who died a week after his mother.

In May 1661, Gravesande married Agatha van Schagen and moved to her house on the Voldersgracht, where her brother kept the shop after the death of their parents. By 1669, Cornelis and Agatha were living on the Koornmarkt and in 1681 on the Oude Delft, corner of the Sint Aagtenklooster. They had 10 children and when Agatha died in 1683, they were living on the Hippolytusbuurt across the gracht from Leeuwenhoek. This house had belonged to Amila Jacobs de Berch, the mother of his first wife and had come into Gravesande's possession after her death in 1681.

Gravesande was appointed Delft's city anatomist in 1661, succeeding Pieter van der Mast. Gravesande did weekly dissections, on Wednesday afternoons (2 PM?), in the Nieuwe Doelen on the Verwersdijk.

Gravesande joined the Veertigraad in 1672, the Disaster Year (Rampjaar), and for following five years made notes about what happened at every meeting.

He served as magistrate in 1680, 1682, and 1683. He and Leeuwenhoek would have come into contact at the Stadhuis as well as at the weekly dissections. Gravesande also served as master of the Orphan's Chamber (1685-1687) and father (1672) and master (1686) of the Meisjeshuis.

In the letter of September 7, 1674, Leeuwenhoek refers to his discussions with a neighbor who, in Leeuwenhoek's words, "encouraged" him. In two other letters a decade later, he mentions a neighbor in similar terms. The editors' running notes to those letters indicate that this neighbor may well have been Gravesande.

According to Houtzager's Snijkunst Verbeeld, 's Gravesande lived on Koornmarkt, now no. 93.

According to the biographical note in Alle de Brieven / Collected Letters (volume 1, pp. 398-401), 's Gravesande lived on the corner of the Nieuwstraat and Hippolytusbuurt, next door to Leeuwenhoek. However, the real estate records ORA 281-283 show that the house was owned before Leeuwenhoek's time by the Cornelis Arents 's Gravesande, the uncle of Dr. Cornelis Isaacs. Cornelis Arents bequeathed it to Francois in 1657. Later, Cornelia (not her cousin the Dr. Cornelis) and husband Jochum Brugman lived there until they sold it to the printer Hendrik Cronevelt in 1688. The same mistake is repeated in Verhoeven's Derde Stad van Holland, p. 418; in 1655, Cornelis Isaacs was studying medicine in France.

This portrait of Gravesande (click for larger size) is by Jan Verkolje, who painted Leeuwenhoek's also. In 1681, Gravesande and Leeuwenhoek sat for Cornelis de Man's group portrait for the surgeon's guild of one of Gravesande's anatomy lessons.

This doctor died five years before his son, the notary of the same name, was admitted.