Faraday to William Tierney Clark¹   18 August 1831

Royal Institution | August 18 1831

My dear Sir

You seem to imagine that I can answer all sorts of questions and that too when you put them almost in the manner of riddles for you tell me nothing relative to the green substance which you sent me or where it came from or under what circumstances found[.]

However I suppose it has been found in stagnant or at least rather quiet water and I believe it to be a conferra i.e one of those minute vegetations which in order of time appear to preceed [sic] many others[.]

If that be the case then your question is a botanical one and I cannot pretend to answer[.] As to stopping its formation I think that may be difficult but I really can give no opinion being entirely ignorant whether it is found in a large or small quantity of water in light or in darkness &c &c and even if I knew these I do not know that I could give a much better answer²[.]

I am | My dear Sir | Very Truly Yours | M. Faraday

W. Tierney Clark Esq | &c &c

Endorsement: Nr 7809 M. Faraday 18 Aug 1831 recd 24 do.