Элеонора Шнап. Друг спознаётся во время большого несчастья, а недруг во время маленьких. Так мой профессор Эссер всегда говорил. Я не могла не прийти... (The Event, Act Two)

Professor's name comes from essen ("to eat") and seems to hint at Hermann Esser (1900-81), a Nazi leader who was involved in sexual scandals. But it also may hint at СССР (the USSR), "the domestic she-beast Eseseria" whose rudeness Merezhkovsky mentions in one of his poems written in emigration:

Доброе, злое, ничтожное, славное,-
Может быть, это всё пустяки,
А самое главное, самое главное
То, что страшней даже смертной тоски,-

Грубость духа, грубость материи,
Грубость жизни, любви - всего;
Грубость зверихи родной, Эсэсэрии,-
Грубость, дикость, - и в них торжество.

Может быть, всё разрешится, развяжется?
Господи, воли не знаю Твоей,
Где же судить мне? А всё-таки кажется,
Можно бы мир создать понежней.

As to Schnap, her surname hints at schnaps. In fact, Esser + schnaps = SSSR + Schnap. The phrase schnaps trinken occurs several times in Chekhov's letters. In a letter of Nov. 25, 1892, to Suvorin (quoted in my previous post), Chekhov complains of the absence of alcohol that would intoxicate the reader in the works of contemporary writers and painters: "Tell me honestly, who of my contemporaries--that is, men between thirty and forty-five--have given the world one single drop of alcohol? Are not Korolenko, Nadson, and all the playwrights of to-day, lemonade? Have Repin's or Shishkin's pictures turned your head? Charming, talented, you are enthusiastic; but at the same time you can't forget that you want to smoke." (the full English text of the letter is available at http://www.google.ru/url?sa=t&rct=j&q=chekhov%2025%2C%201892%2C%20to%20suvorin%20&source=web&cd=1&sqi=2&ved=0CCQQFjAA&url=http%3A%2F%2Fwww.readbookonline.net%2Fread%2F40122%2F79955%2F&ei=ApgqT5jGOOqk4ASMjan-DQ&usg=AFQjCNEltMoRyS4OYeGCFYlZbp4AilQKsg) Btw., Chekhov's contemporary, Merezhkovsky wrote a book on Leonardo da Vinci.

Shnap's first name, Eleonora reminds one of E. A. Poe's Lenore (who is mentioned in Blok's poem "Осенний вечер был..."*) and Buerger's Lenore (who is mentioned in Eugene Onegin: Eight: IX: 7-8). The characters in Chekhov's one-act play "Свадьба" ("The Wedding," 1890) include the midwife Zmeyukin ("Mrs. Viper").