Richard Waller wrote to Leeuwenhoek about colors and sperm inside of eggs
Text of the letter in Alle de Brieven / The Collected Letters at the DBNL - De Digitale Bibliotheek voor de Nederlandse Letteren.
Waller acknowledged receipt of two letters from Leeuwenhoek. He asked Leeuwenhoek to look microscopically at the colors not only of birds' feathers but of:
other coloured bodys; possibly the same thread of silke, dyed of different colours, might be examined to see what alteration is made in the outward or inward parts therof, wch causes that different reflexion of Light giving those colours; possibly painters Colours may be fit subjects, and possibly the several disguises of Mercury in white, red, yellow and the like might give different appearances of ye constituent parts in the microscope, which I leave to yr choice
He also inquired whether Leeuwenhoek had observed sperm inside of an egg.
Letter Book Original, vol. XI, part I, pp. 205-206.
