I do not have an argument but rather a suspicion. Lady Audley’s Secret was serialized (in several magazines, oddly), and although the plot is slick enough that I am sure Braddon planned it out ahead of time I am convinced that she ran into a problem with length. Since the plot frame had already been built, so to speak, she had to pad the book with digressions and strangely detailed descriptive passages that become more frequent in the last third or so. Near the beginning, the narrator’s intrusions look like this:
If any one could at that moment have told the young barrister that so simple a thing as his cousin's brief letter would one day come to be a link in that terrible chain of evidence afterward to be slowly forged in the only criminal case in which he was ever to be concerned, perhaps Mr. Robert Audley would have lifted his eyebrows a little higher than usual. (I.VII)
Clumsy and unnecessary. Later, though:
The floating mists from the boiling liquid in which she infuses the soothing herbs; whose secrets are known to her alone, envelope her in a cloud of scented vapor, through which she seems a social fairy, weaving potent spells with Gunpowder and Bohea. At the tea-table she reigns omnipotent, unapproachable. What do men know of the mysterious beverage? Read how poor Hazlitt made his tea, and shudder at the dreadful barbarism. (II.VII)
The passage goes on and on and is about nothing but Woman’s superiority at making tea; as far as I can tell it is utterly incidental to the story, and thus is both filler and a place where Braddon felt she could cut loose with the juicy, grapey purple prose.
What I am imagining is a mystery novel written by Tristram Shandy’s great-niece, one in which the commentary eventually subsumes the story. Braddon did not write that book. She did write this:
Knitted curtains shaded the windows, in which hung wire baskets of horrible-looking plants of the cactus species, that grew downward, like some demented class of vegetation, whose prickly and spider-like members had a fancy for standing on their heads.
The green-baize covered card-table was adorned with gaudily-bound annuals or books of beauty, placed at right angles; but Robert Audley did not avail himself of these literary distractions. (II.VIII)
Detective Audley is at a school for girls, looking for the truth about Lady Audley. If this were a Nabokov novel I would file away the “right angles,” surely a link to another scene, say II.XIII, “the looking-glasses, cunningly placed at angles and opposite corners by an artistic upholsterer, multiplied my lady's image, and in that image reflected the most beautiful object in the enchanted chamber,” and the green baize, too, which appears in I. VIII, “My lady's portrait stood on an easel, covered with a green baize in the center of the octagonal chamber.”
When I knock these passages together, they begin to suggest a control of the detail work that I do not believe Braddon really had. Amazing the patterns our imaginations create. Note to Googling students of Prof. Maitzen: surely this is a dead end. Go back before it is too late! (Hint: follow the pre-Raphaelite theme instead).
Regardless, that cactus is worth seeing, and perhaps even better is the implication that the Audley might possibly be tempted from his purpose by gift books for girls. That is clearly Shandy’s niece speaking – who else would want to know what is in those tedious books?
I guess what I am doing here is enjoying the passages where Braddon most seemed to be enjoying herself.