Robert Hooke wrote to Leeuwenhoek that King Charles saw the little animals in pepper water

Date: 
April 18, 1678

Hooke dated the letter in Old Style; it was April 28 in Delft.

Four years later, Leeuwenhoek responded in Letter 36 of 1682-04-04 (AB 68) with a quotation from Hooke's letter and a long response.

Document: 

Copy found in Royal Society's Letter Book Original, supplement 4 GH, pp. 373-75

Answer to Mr. Leeuwenhoek's Letter of Jan: 14: on Animalcula: with some account of the Structure of a Muscle in Crabs, Lobsters, &c.

April 18: 1678

Sir,

Having not heard from you since I returned you mine together with the thanks of the Royal Society for your excellent Communications, makes me suspect the miscarriage thereof: and this the more, because by a Letter of yours which pass'd thro' my hands to Dr. Grew I found no mention thereof. I do here therfore again reassure you of the very kind acceptance and thanks of the Royal Society for your Letter of the 14th of January last. And together with them I have sent you the translate thereof into our Language, together with some few Observations and Collections of my own: which I had sent sooner, if I could have found an opportunity of conveying them.

The Prospect of these small Animals have given great Satisfaction to all Persons that have view'd them. His Majesty having been acquainted with it, was desirous to see them, and very well pleased with the Observation, & mention'd your Name at the same time. I know not whether any of these ways I have here made use of for the discovery of them may be in any thing like those with which you make your Observations. But I have two or three other ways, which I shall shortly communicate, that do far exceed those I have here mention'd.

About a month since I shew'd the Society the Fabrick and Composition of a Muscle: some mention of which you will find in the inclosed Treatise, but not what it was. I shall, that I may not prepossess your Judgment, only mention to you, that the muscles that I chose were those of Crabs, Lobsters, Crawfish or Prawns & those especially of the great Claws. If you examine them, I am sure you will find a Fabrick which will very much please you: and I doubt not but your Opinion and Observations will very much confirm mine: which when you have examined I would willingly understand.

I have not as yet settled my affairs so well as to prosecute the business of Correspondence for the Royal Society so fully as I determine to do; which when I have, I shall have much better opportunity to gratify your Curiosity with some more pleasing Communications. In the mean time what occurs to my own Observation, that I conceive may not be unacceptable, shall be sent you by

S.r Yrs &c   R.H.