Jonathan Harker's Journal, May 28
Harker tries to send some real letters home to Peter Hawkins and to Mina with a group of Szgany, or "gypsies," as he calls them. He sees them from a window, and tosses the letters down, along with a gold piece, and tries to convey to them with sign language that he wants them to mail the letters for him.
The letter to Peter Hawkins just tells him to contact Mina.
The letter to Mina is written in shorthand, and tells her that he's a prisoner in Castle Dracula, but he leaves out the gory details.
Later on, Dracula appears in his room, holding the two letters.
He says that the Szgany gave the letters to him, and, not knowing what they were, he opened them.
He offers to send the letter to Peter Hawkins on, but tears up the one in shorthand because he can't read it – he pretends not to know that it's from Harker.