To John Tyndall   7 March [1871]¹

My dear Tyndall

I wrote about a week ago, explaining that my D^r. Ogle was not the same as yours, & asking whether he might call on you.—² But the two men may make all the difference to you.— As my man has been very obliging to me, I much wish to make him some answer.— Forgive me for bothering you.— Shall I say that you have not attended to odorous particles & are sorry that you cannot give him the desired information?³ Or anything else you may determine on. I know how busy you must be.—

Yours very sincerely | Ch. Darwin