Received Letter L-374 from Hans Sloane with larvae to examine

July 19, 1700

After the long period during which Edmond Halley edited Philosophical Transactions and did not publish Leeuwenhoek, he was eager to work with the new editor, Hans Sloane. Sloane had visited Delft earlier in the year, so when he sent some specimens to investigate, Leeuwenhoek responded immediately. He reported his observation in a letter eight days later, on July 27.

The three larvae that Sloane sent came from John Chamberlayne, who would translate Leeuwenhoek's letters into English for Philosophical Transactions from 1700 to 1712, when Halley again became editor and again did not publish Leeuwenhoek's letters. The larvae had come from Chamberlaine's decayed tooth. He sent them to Sloane on July 3 (O.S.), and Sloane sent them on to Leeuwenhoek the next day. Four days later, July 8 O.S., July 19 N.S. in Delft, Leeuwenhoek received them. Two had died; Leeuwenhoek kept the other alive for a couple of months while he investigated.

After observatation and experiment, Leeuwenhoek reported back to Sloane that the larvae may well have come from cheese. He also thought that any associated pain came from the larvae's chewing. (We now know that the pain comes from bacteria.)

After sending his reply, Leeuwenhoek continued studying the larvae. He followed up with another report to Sloane in a letter on September 7, 1700 (AB 218).


Letter L-375 of 27 July 1700 to Hans Sloane

I received Your very welcome letter of the 4th of July old style on the 19th of this month new style, and having at once opened the piece of black silk lying in the letter, I found in it two dead and one living little larva, which You say were sent to you by Mr. Chamberlaine, with the request that You should send them to me, as having been got by fumigating out of a decayed tooth.