Dear Sir/

I re^cd your letter ^<1> from Worthing for which let me thank you and for the remarkably elegant formula for the latus Rectum of a Conic Section. I also found on my return to Town your paper on Col^d flames which I shall as you desire immediately forward to D^r Brewster. ^<2>

I was not aware you were about to quit England so speedily. ^<3> My only acquaintance at Geneva now & Maret & Pictet ^<4> are no more, is Professor Gautier, ^<5> to whom I annex a letter. I

I wish you a pleasant journey and if I could slip myself into your portmanteau I should be very glad.

Yours truly
JFW Herschel

P.S. I am not sure whether an acquaint^ce of mine M. Soret ^<6> is at Geneva still if so I have requested M^r Gautier to introduce you to him, as he is very conversant in Physical optics and has written some good papers on the action of Crystals on light. ^<7> Also he may be of use to you in other ways as he was to me by giving me free access to their “Athenæum” &c &c

Devonshire St

Wednesday evening

PPS. Will you do me the favor also to deliver to M^r Gautier the annexed Vol of the Trans. Astr. Soc. for the Helvetic Society ^<8>

H. F. Talbot Esq^r
Albany

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Notes:

1. See Doc. No: 01386.

2. Dated March 1826, this paper was published by Sir David Brewster (1781–1868), Scottish scientist & journalist, as WHFT, ‘Some Experiments on Coloured Flames’, The Edinburgh Journal of Science, v. 5 no. 1, June 1826, pp. 77–82.

3. WHFT left spent nearly 6 months travelling in 1826, taking in Greece and visiting William Thomas Horner Fox Strangways, 4^th Earl of Ilchester (1795–1865), botanist, art collector & diplomat in Corfu. [See Doc. No: 01355, and letters of that Spring and Summer to WTHF Strangways].

4. Marc August Pictet (1752–1825), natural philosopher.

5. Alfred Gautier (1793–1881), astronomer and geologist.

6. Frédéric Jacob Soret (1795–1865), scientist.

7. Herschel was probably referring to his Recherches sur la position des axes de double réfraction dans les substances cristallisées (Geneva: Paschoud, 1821).

8. Transactions of the Astronomical Society.