Michel CHASLES (1793-1880), mathematician and famous autograph collector. 4 autograph letters signed to the chemist Edmond Frémy (1814-1894), professor at the Muséum. 4 pp. in-8 with his embossed cipher. 1859-1872 and n.d. "If you wish to speak on Monday, you must come in person to renew your request to your vice-president [...]". "Mr E.B. [Edmond Becquerel?] may have neglected to send his notice to the free academics. They are entitled to take part in the discussion of titles in the committee [...]". "If you were free tomorrow evening, Thursday, and came to have a cup of tea, you would give me great pleasure, and you would give me the opportunity, which I impatiently await, to ask you to lecture your friend Mr Longet, from whom I received two beautiful volumes yesterday [...]". "...] Earlier I heard from Mr Decaisne that you were not in Paris. I was planning to go to the Museum [...]".