How we cite our quotes: (Chapter.Paragraph)
Quote #4
The Morgue is a show that anyone can afford, which poor and rich passers-by get for free. The door is open, anyone can come in. There are connoisseurs who go out of their way not to miss one of these spectacles of death. When the slabs are empty, people go out disappointed [...]. When the slabs are well-filled, and when there is a fine display of human flesh, the visitors crowd in, getting a cheap thrill, horrified, joking, applauding or whistling, as in the theatre. (13.12)
Zola presents the morgue as a place of entertainment: admission is free and people can come to see death on display. In addition to serving as a source of entertainment, the morgue also reproduces Zola's metaphor of the scientist. When people visit the morgue, they observe the corpses through a window, like a scientist observing specimens through a microscope.
Quote #5
The murderer slowly went over to the window as though drawn by a magnet, unable to take his eyes off his victim. [...] He stayed motionless for five whole minutes, lost in unconscious contemplation, involuntarily marking in the depths of his memory all the frightful lines and foul colours of the scene before his eyes. (13.17)
The violence, the violence. When Laurent sees Camille's drowned body, he can't take his eyes off of it, even though it scares him to the bone. The sight of Camille's deformed head will haunt Laurent for the remainder of the novel.
Quote #6
Only the pain, the horrible smarting pain, had made him demand a kiss from Thérèse, and when Thérèse's lips had proved to be cold against his burning scar, he suffered even more. This kiss, obtained by violence, had broken him. (21.38)
Laurent's desire to alleviate the pain of his scar pushes him to beat on Thérèse. (FYI, spousal abuse is so not okay.) Violence is shown as a highly destructive force in this passage.