Robert Hooke wrote Letter L-072 to Leeuwenhoek that King Charles saw the little animals in pepper water

April 28, 1678

Hooke dated the letter 18 April 1678 O.S. in London.

In this letter, Robert Hooke writes to L. in response to his Letter L-067 of 14 January 1678 about little animals in pepper water and mentions that King Charles II has seen them, too, with pleasure. Hooke adds an account of his observations of the structure of muscles in crabs, lobsters, crawfish and prawns.

Hooke’s Lectures and Collections, published in 1678, does not mention anything about muscles of crabs, lobsters, crawfish, or prawns. At several meetings of the Royal Society in March and April 1678, Hooke demonstrated features of muscles for the members. See Birch, The History of the Royal Society of London, vol. III.

Four years later, Leeuwenhoek responded in Letter L-119 of 1682-04-04 with a quotation from Hooke's letter and a long response.

Hooke’s previous letter to Leeuwenhoek is Letter L-068 of 11 February 1678, to which Leeuwenhoek did not respond, preferring instead to send his next five letters to the Royal Society to Nehemiah Grew. However, in Letter L-119 of 4 April 1682 to Hooke, Leeuwenhoek gives a loose translation of the final two paragraphs of the present letter, suggesting that either Leeuwenhoek had the letter translated for him or he could read the English well enough himself. For another translation from English to Dutch around the same time, see Letter L-135 of 17 September 1683 to Francis Aston.

Charles II reigned from the 1660 restoration of the monarchy until his death in 1685. After the Royal Society was founded in 1660, Charles granted it a royal charter in 1662.


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


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.