My dear M^r. Aubertin.

I received your letter dated April 27^th. many weeks ago, but only yesterday the stones—¹ I do not suppose anyone without examining the country could form a guess how thick the rocks, of which you sent specimens would run.— They form a very coarse micaceous schist, & I can well believe must be most difficult to tunnel through   One may conjecture that the case is more hopeful than if the rock had been granite or porphyry— The rocks belong to the metamorphic series which I believe is developed to a larger extent in Brazil than in any other quarter of the world. I saw no other rocks besides these & Plutonic in Brazil & I examined a series collected along the whole coast from Rio to near the Plata—² I thank you for your very kind & long letter which interested me much; especially about the progress of the mulattoes. &^c. I am very glad to hear that you are well & endure your life— I heard of your appointment shortly after you sailed—³ I cannot give a very good account of myself, as I am constantly ailing— My eldest daughter thank God is well,⁴ but one of my Boys is an Invalid⁵ & we had fearful illness in our family last year.⁶ M^rs. Darwin is well and begs to be kindly remembered to you— Owing to the state of our Family we have not seen anything of Miss Butler for a long time, but she has visited us here once or twice & was as pleasant as usual.⁷ Of Miss Scott I know nothing.—⁸

I can tell you of only one other Ilkleyite, namely M^r Robinson; & he is married and has a living.—⁹

Will you grant me a little favour, I have a Boy, who remembers you, & is a passionate collector of postage stamps.—¹⁰ He tells me that there are many kinds used in Brazil, now will you devote an envelope & tear off any old stamps which you may receive, & when you have got a few send them through your London Correspondent. You would give great pleasure, if you would take so much trouble  

with every good wish for your success & health. | Pray believe me my dear M^r. Aubertin— | Very faithfully yours. | Ch Darwin.