Final answer:
The question references Monsieur de Villefort, a character from 'The Count of Monte Cristo', but the provided text snippets do not align with this character or situation. For this reason, it is not possible to give an accurate answer based on the given excerpts.
Step-by-step explanation:
The question seems to refer to a character named Monsieur de Villefort, whose case preparation after a death is of interest. However, the excerpts provided do not reference a character by this name or an associated case.
Instead, the passages discuss various characters and situations from different literary texts, such as the preservation of lady Madeline's corpse, Venters and his vigil next to a dying girl, Aylmer's plans for an operation on his wife, Dupin and his crime-solving in Paris, and Winterbourne's experiences in Rome.
It appears there has been a mix-up with the texts since these passages don't relate to the original question about Monsieur de Villefort, who is actually a character from Alexandre Dumas's 'The Count of Monte Cristo'.
In the novel, after the death of Valentine, Villefort is preoccupied with proving the innocence of his son in court.