I believe Finn Magnussen of Copenhagen is dead, but may be mistaken.

Gilliss thinks Dr de Angelis of Buenos Ayres is still living.

De ceteris non liquet.

I pray you have King Solomon put to the question touching that big book, which hath not been delivered to

Prof Baird

References in this letter:

Finn Magnusen was the author of an Icelandic dictionary, Om de Engelskes Handel og Faerd paaa Island, 1833.

James Melville Gilliss (1811-1865) was both a naval officer and astronomer. He was responsible for proposing and supervising the building of Naval Observatory in Washington, DC (1842-1844). In 1846 he was assigned to the U.S. Coast Survey and spent several years in Chile conducting astronomical observations. The Gilliss family, based in Washington, became close friends of the Marshes and the Bairds.

Pedro de Angelis (1784-1859) was an Argentinian historian and writer. De ceteris non liquet

Latin: concerning (all) the rest of the issues, no judgment can be made. The phrase "non liquet" is legal formula.