IJsak van Krimpen

Other name: 
van Emden, Isaac, Krimpe, Crimpen
friend, sea captain who provided whale parts for Leeuwenhoek to study
Death or Burial date: 
December 8, 1716

contributed by Johan Geertzenwijk

In Leeuwenhoek’s time, whales were hunted because of their crude body-fat. whale-oil (traan) was extracted from the fat by cooking it. The oil was used for fuel in oil-lamps, for making soap, and in the leather industry. Until 1646 the island of Amsterdam near Spitsbergen was used for processing the fat at the factories in Smeerenburg, erected by Delft and other cities. After abandoning Smeerenburg, the oil was made in Holland, especially in the area of the Zaan, but there were also factories in Amsterdam (Nieuwendam) and Rotterdam. The ships took ballast with them in the form of barrels filled with water, later replaced by the whale fat.

According a study by Pieter Dekker, Commandeurs ter walvisvaart uit het gebied van Maasmond en Lekkerkerk in de achttiende eeuw, Isaac Krimpe was active in the period 1700-1716 as commander. He said for the ship owner Bartholomeus van Halen, of Amsterdam, for whom van Krimpe had a catch of 109 whales from the sea east of Greenland.


In 1662, a whale stranded at the beach of Scheveningen. It was many years later that Leeuwenhoek got interested in detailed research about the whale. He wondered whether the large size of the animal corresponded with larger blood cells, muscle fibers and sperm than he had observed in smaller animals like dogs and fleas.

In 1703, when the fleet of whale hunters had come home, Leeuwenhoek got a piece of whale-meat, but it was dried out, rotting, and smelled like it. From a workman who had a friend that had been involved in the hunt, he got the lens of a whale’s eye. A fellow citizen, Mr. Frederik Wolfert van Overschie, gave him two more lenses from different whales, taken home by a commander. Some years later Leeuwenhoek got acquaintand with a 'commandeur' named Isaac van Krimpen. He asked Krimpen to bring home a part of a whale’s genital organs, with the idea that they could contain some sperm.

Krimpen had lived before 1703 in Delfshaven. With some other commanders, he was employed by the ship owner Bartholomeus van Halen. At Delfshaven was also living the painters Adriaen van der Salm and his son Roloef, who made several pen-and-ink drawings about the whale hunt. On one of them is depicted a ship named 't Bonte Kalf (the largest, closest ship on the left side of a section from this drawing; click to enlarge), a ship on which Krimpen was commander in 1698. After remarrying in 1703 and before sailing out, Krimpen had moved to a house on the Oosteinde in Delft.

In 1704 and 1705, he got from the Municipality of Delft certificates of registry for a ship named Juffrouw Cornelia.

Vergunningen aan schippers tot door- en uitvoer van goederen zonder betaling van Licentie (Permits to skippers to transit and export goods without payment of License) (Arch. Delft 1, inv. 4084)

  • 1704-04-01. Isaak van Crimpen given two sea letters as a German and a French ship the Juffrouw Cornelia, 190 lasts (see right sidebar)
  • 1705-03-24. Isaak van Crimpen from Delft after Greenland with the ship Jufr. Cornelia, 190 lasts

The Opregte Haarlemsche Courant published news about ships that were sailing out and returning home. In 1711 the newspaper announced that the fleet of whale hunters sailed from Tessel on the 19th of April. The War of the Spanish Succession made the journey over the North Sea troublesome. French privateers were a permanent risk. Ships destined to Suriname chose a route north around Brittain, in an armed convoy, from which the whale hunters profited.

That year they returned home late because of bad weather and a contrary wind. On the 3rd of October the main part of the fleet arrived at Tessel, including Krimpen. He brought with him a whale’s genital organs. According the telling of Krimpen, 'traan' had dripped out of the organ, so Leeuwenhoek understood that the chance of finding sperm was minimal. Indeed, he didn't find any. Later on he got a piece of skin. Also he got two pieces dried whale meat. After his examinations, Leeuwenhoek wrote: "I was astonished more than before about these observations, because I had assumed that the flesh parts of such big creatures as the whale, would also consist of larger parts of their bodies."