Grotesque appetites are a motif in the novel. One example occurs in Chapter 3, when young Ned Higgins seems to be insatiably hungry for Hepzibah's gingerbread cookies (which are themselves an allusion):
She had just placed another representative of the renowned Jim Crow at the window, when again the shop bell tinkled clamorously, and again the door being thrust open, with its characteristic jerk and jar, disclosed the same sturdy little urchin who, precisely two minutes ago, had made his exit. The crumbs and discoloration of the cannibal feast, as yet hardly consummated, were exceedingly visible about his mouth.
The cookie Ned has just devoured is a "representative of the renowned Jim Crow." Jim Crow was a popular blackface minstrel character in the 19th century, after whom the "Jim Crow era" of the 20th century was named. Drawing on an African American folk figure named Jim Crow, a white playwright and performer named Thomas D. Rice made money by donning blackface makeup and performing as a racist caricature of a Black person. Wright's performance was pitched toward white audiences. It aimed to make them laugh by exaggerating the differences between a white man and the Black stereotypes he was embodying. This performance and the character at its center became so popular that the character's image began to appear everywhere. With the development of technologies in photography and printing, images of Jim Crow started to show up even on mundane household items such as plates, an everyday reminder of the supposed inhumanity of Black people. In her cent shop, Hepzibah is selling likenesses of Jim Crow in the form of a cookie.
Ned devours the cookie and comes back for more, the crumbs and stains from his "cannibalism" still on his face. He can't stop eating up Jim Crow. His appetite is an unsettling representation of American consumerism, which Hepzibah and Hawthorne alike find rather distasteful. Ned should be satisfied with one cookie, but he is back for seconds before even cleaning up the mess from his first cookie. Ned is putting no critical thought into what he is consuming; whatever the market makes for him to consume, including distasteful and racist images of Jim Crow, he will gladly swallow.
What's more, the idea that Ned is a "cannibal" flips the usual script by which 19th century Americans discussed race. Colonists frequently called Black and Indigenous people "cannibals" in order to dehumanize them and excuse colonial violence against them. Here, a little white boy is a cannibal consuming a Black body. Racism is still at play: part of what Hawthorne seems to imagine will make this scene unsettling to white readers is that consumerism is giving Ned the insatiable appetite of a "savage" non-white cannibal.
Ned appears again and again with the same appetite for Hepzibah's gingerbread cookies, all in the shapes of living creatures. But his is not the only insatiable appetite. The entire plot is driven by the Maules' and the Pyncheons' appetites for wealth and property. The more they want, the more unhappy they are. Although the deed to the land in Maine is eventually revealed at the end of the novel, the real happy ending comes with everyone's freedom from the House of the Seven Gables, and from the appetite for wealth that has long cut them off from healthy community among their fellow humans.
In Chapter 14, Holgrave alludes indirectly to Mary Shelley's Frankenstein:
Miss Hepzibah, by secluding herself from society, has lost all true relation with it, and is, in fact, dead; although she galvanizes herself into a semblance of life, and stands behind her counter, afflicting the world with a greatly-to-be-deprecated scowl.
Shelley's novel tells the story of a young scientist who becomes deeply obsessed with arcane knowledge and long-dead scientists and philosophers. Far too obsessed with dead people for his own good, Dr. Frankenstein conducts an experiment: he harvests, from dead people, all the body parts to make up a human and shocks his new creature to life. Frankenstein, or the Modern Prometheus, is one of the earliest works of science fiction. It is a tale of science gone awry, and of the desperate need for humans and human-like creatures to be brought up in sympathetic community with other humans. In her 1831 preface to Frankenstein, Shelley explained that galvanism was the scientific process through which the creature may have been brought to life. Galvanism, named after an Italian doctor named Galvani, is the use of electricity to animate biological processes. Galvani famously used it to make a dead frog's legs twitch; Shelley's novel imagines this technology taken to its fullest extent.
Hawthorn does not introduce a new or fantastically advanced technology into his novel, but he is deeply interested in the human impacts of technological advances. In particular, he is interested in the new ways technology allows humans to think and speak about their own experiences. In this passage, Hawthorne, via Holgrave, alludes to the galvanism that brings Frankenstein's creature to life as a way of explaining what happens to Hepzibah when she steps behind the counter of her cent shop. She is not truly alive, at least not in the sense that a person fully engaged in human society is alive. Instead, she shocks herself to some semblance of life out of the necessity to make money. She is like Frankenstein and Frankenstein's creature alike, walking through the world but not truly a part of it because she has cordoned herself off from her neighbors. Galvanism and Shelley's science fictional account of it allow Hawthorne to get at something about Hepzibah that he otherwise would not be able to capture. The allusion helps him compare Hepzibah's anti-social life to the experience of being both dead and alive, and also neither dead nor alive.
In Chapter 20, the narrator alludes to the creation story in the Bible's Book of Genesis to describe the effect of Phoebe and Holgrave's love for one another:
They transfigured the earth, and made it Eden again, and themselves the two first dwellers in it.
In Genesis, Eden is the paradise where Adam and Eve, the first humans, live until they are cast out for disobeying God. Christianity is often framed as a fight to return, one day, to a restored paradise. Phoebe and Holgrave, Hawthorne suggests, manage to do just this for the Maules and the Pyncheons. No one has been happy in the House of the Seven Gables since the two families first turned against one another over ownership of the land. The ground has essentially been poisoned by the Maules' bitterness and the Pyncheons' greed. Even Phoebe, who arrives at the house as a veritable ray of light, cannot help but grow dimmer the longer she stays there. Phoebe and Holgrave's love promises to take all the poison out of the ground. Descended from the original Pyncheon and Maule, this new couple resolves the longstanding conflict by uniting the two families and consolidating their interests. No longer is there a reason for one family to keep any property out of the other family's hands because their wealth will now be shared.
Clifford repeats this allusion later in the chapter. It helps explain his enigmatic return to the house after he swore he was leaving it for good and embracing a life of travel:
“It is our own little Phoebe! Ah, and Holgrave with her,” exclaimed he, with a glance of keen and delicate insight, and a smile, beautiful, kind, but melancholy. “I thought of you both, as we came down the street, and beheld Alice’s Posies in full bloom. And so the flower of Eden has bloomed, likewise, in this old, darksome house today.”
The last time the reader saw Clifford, he was explaining how terribly confining it was to be attached to a house. His happy return is what allows him to be acquitted of the two murders he once appeared to have committed, but it is at odds with his stated intention to leave the house in his past. One explanation for his return is that he simply could not escape the gravitational pull of the house and its terrible history. But his appearance just after Phoebe and Holgrave have declared their love for one another suggests that he may have been pulled back instead by the exorcism of that history. Whatever his reason for returning, Clifford appears "stronger" than Hepzibah now that he sees Phoebe and Holgrave together, and Alice's posies in full bloom. Whereas Clifford spent much of Chapter 17 describing how uninhabitable the House of the Seven Gables was, Phoebe and Holgrave's union has allowed him to return in full health.
