“Pis'mo IV” [“Letter IV (to Countess Ye P. Rostopchina)]” (1839) is from a series of letters written by Odoevsky to Yevdokia [“Dodo”] Rostopchina, herself a writer and society hostess, “on apparitions, superstitious fears, sensual deceptions, magic, cabbalism, alchemy and other mysterious sciences” (see Neil Cornwell's introduction to The Salamander, 4). It is seen as “a viable short story in its own right” and it features Count Saint-Germain, “a legendary but historical figure used by Pushkin in his Gothic masterpiece The Queen of Spades (1833), who has recently re-surfaced in Umberto Eco's occult extravaganza, Foucault's Pendulum” (ibid.).
Sucur, Slobodan. "Pis'mo IV". The Literary Encyclopedia. First published 21 April 2005
[https://www.litencyc.com/php/sworks.php?rec=true&UID=16755, accessed 23 March 2018.]