what function do letters serve in this and previous chapters

The entirety of Frankenstein is contained within Robert Walton’s letters, which record the narratives of both Frankenstein and the monster, to his sister (even Shelley’s preface to the book can be read as an introductory letter). Walton’s epistolary efforts frame Victor’s narrative, which includes letters from Alphonse and Elizabeth. Like Walton’s, these letters convey important information that serves to advance the plot and offer some sense of authenticity to an implausible story. Additionally, Victor’s inclusion of these personal letters in his narrative allows Alphonse and Elizabeth to express themselves, shedding light on their respective concerns and attitudes, and thus rendering them more human.

Shelley’s use of letters enables the shift of narrative from one character to another while remaining within the bounds of the standard novel. Letters also serve as a means of social interaction, as characters are frequently out of immediate contact with one another. Walton never encounters his sister in the novel; his relationship with her is based wholly on correspondence. Likewise, Victor often isolates himself from his loved ones; the letters from Alphonse and Elizabeth mark attempts to connect with him. Even the monster uses written communication to develop a relationship with Victor when, at the end of the novel, he leads him ever northward by means of notes on the trees and rocks he passes.

The function of the letters written to Victor serve as a communication between him and his family, but mostly only sad news is given to victor