Wrote Letter L-022 of 1675-02-11 to Henry Oldenburg about crystals, vinegar, soap, spices, cod, louse, and oak leaf.

Date: 
February 11, 1675
Standard reference information
L-number: 
L-022
Leeuwenhoek's number: 
10
Collected Letters number: 
16
Collected Letters volume: 
1

Text of the letter in the original Dutch and in English translation from Alle de Brieven. The Collected Letters at the DBNL - De Digitale Bibliotheek voor de Nederlandse Letteren

The original manuscript on 19 folio pages, written and signed by Leeuwenhoek, along with two pages of figures, drawn by him, is preserved at the Royal Society (MS. 1839. Early Letters L1.11). Oldenburg's English translation is Early Letters L1.12.

Leeuwenhoek wrote this letter to Henry Oldenburg about crystals, vinegar, soap, spices, cod, louse, and oak leaf.

the crystallisation of salts and infusions; vinegar, Spanish soap and common soap, aqua fortis (nitric acid and sulphuric acid), pepper, mustard; the globules in the bile of different species of fish; further the optic nerve of cod and cows; cod's roe; objections to Francis Redi's figure of a louse. Veins of an oak leaf. Figures of the crystallisation of salts attached. Other diagrams mentioned in the letter are not attached.

In this letter, Leeuwenhoek tells of observing many salts and some herbs after soaking them. Sometimes he observed them wet, sometimes dried. He was curious about taste, among other things. These herbs included pepper soaked in rainwater. However, Leeuwenhoek reported seeing only little globules, not little animals.

He again reported on his observations of "globules" in bile, the optic nerve, and cod roe.