Emerson, in his famous lecture on "The American Scholar," declared: "The human mind ... is one central fire, which flaming now out of the lips of Etna, lightens the capes of Sicily; and, now out of the throat of Vesuvius, illuminates the towers and vineyards of Naples. It is one light which beams out of a thousand stars. It is one soul which animates all men."' The volcano that animates Dickinson's writing, however, is a far more violent force, an image of devastating linguistic expression erupting out of silence: "Vesuvius dont talk—Etna—don’t—one of them—-said a syllable—a thousand years ago, and Pompeii heard it, and hid forever—" (L 233). Dickinson's volcano emits not only light but consuming lava:
[. . . .]
In contrast to Emerson's image of benevolent spiritual enlightenment, Dickinson's volcano consumes, burns, and destroys. The volcano is an unpredictable, subversive force, more appalling when it erupts because it has been so long silent. Yet the subtlety of the volcano persists even in the eruption, which is only a hiss, and in the destruction, which is an oozing away. Far from being limited by its constraining rock, the volcano's power of expression is so great that it can swallow up the exterior that seems to confine it. As such, it offers an image of Dickinson writing from within the confines of her society, exploding the language by which her culture seeks to limit and define her. . . . Dickinson's disruption of social structures, like her poetic image of the volcano, is primarily a linguistic one. The volcano destroys cities that are, like conventional language and grammar, constructions of civilization. But just as the fiery lava and ash also resculpt the landscape and enrich the soil, Dickinson's disruption of conventional discourse also reshapes and enriches language.From "Emily Dickinson’s Volcanic Punctuation" in The Emily Dickinson Journal (1993).
"A still – Volcano – Life – " begins by making disruptive thoughts or feelings of "Life" concrete through the metaphor of a (nongendered) volcano. . . .
The poem's first two stanzas emphasize the secrecy of such a life. At the end of the second stanza, however, Dickinson moves out from the abstract soul to the physical (and in this case implicitly gendered) body to give more intimate and immediate impact to her metaphor:
The lips that never lie –
Whose hissing Corals part – and shut –
And Cities—ooze away—
The multiple suggestive aspects of female sexuality in the final stanza's images (the speaker's undetected, clearly non-phallic, metonymic ability to "ooze"; the coral lips which might belong either to the mouth or to the more frighteningly "quiet" vagina; and perhaps even the volcanic heaving bosom) point to the centrality of the body in imagining this Life's eruption.
As with all of Dickinson's metaphors of grotesquerie, this stanza offers two surreal pictures. In the first, a speaker's "hissing Corals" part to release lava—like words, expressions, or fluid so destructive that "Cities" are destroyed. One of the more chilling aspects of this image lies in the lack of anger or intention in the volcano's action: whether the speaker utters curses or merely parts her lips in a smile, the result is equally destructive. At the same time, the metaphor depicts a volcanic mountain with the "lips" of a siren, sensuously "hissing," "part[ing]" and "shut[ting]" as it slowly releases its molten rock. In either case, the body disappears except for the magnified and red lips, which give immediate and frighteningly controlled release to the "Volcano – Life" within. In a grotesque metonymy, a woman becomes a mouth—or that other dangerous and lipped female orifice—spewing violent destruction. Here there is no obvious humanity to which a victim of the "hissing Corals" might appeal.
[. . . .]
A human volcano, with lips prominent and sensual, whose expressions make "Cities – ooze away" evokes horror, disbelief, but also amusement at the incongruity of the speaker's self-aggrandizing fantasy: the speaker implies that she might at any time choose to open her coral lips and release destruction, that beneath her white dress lies volcanic fury. . . .
This poem suggests a sensibility that values a sexually female power wholly alien to (or in tension with) notions of femininity in a staid New England community. . . .
[T]he speaker reveals a kind of glee in knowing what the "North cannot detect" . . . . The speaker is not interested in politeness but in volcanic honesty that simultaneously reveals and devastates.From Comic Power in Emily Dickinson. By Suzanne Juhasz, Cristanne Miller, and Martha Nell Smith. (University of Texas Press, 1993). Copyright © 1993 by the University of Texas Press.
Joanne Feit Diehl
Whereas Emerson and Dickinson are both drawn to the vision of an imminent power that smoulders undetected, Dickinson "personalizes" this vision. Volcanic force is no longer associated with universal man as in "The American Scholar," but, instead, with the single life. Power does not run through all of us, as Emerson maintains; furthermore, it cannot be apprehended by anyone who observes the seemingly quiet, single self. The one soul which animates all men now stands isolated and alone. . . . This single life erupts irrevocably. Hidden, mysterious, still, the power floods mechanically; corals "part and shut"—destroying cities. What distinguishes this from Emerson's volcano is Dickinson ' s insistence on secrecy, on individuality, and on destruction. The poems will go further to identify this oral potency with both poetry and the self.
Moreover, Dickinson's practice of defining her self against Emerson's while drawing upon his language recurs in varying forms. Although she may alter the thrust of an Emersonian image or impose her own priorities on his diction, the new poem lies hidden in its parent text. Characteristically, a Dickinson poem takes an example that Emerson introduces into an essay and invests it with the strength of a subversive, anti-Emersonian vision.From Dickinson and the Romantic Imagination. Copyright © 1981 by Princeton UP
Marinela Carvalho Freitas
In Emily Dickinson's poem "A still—Volcano—Life—" (no. 601) we find, very well developed, the image of the volcano in all its metaphoric and symbolic significance. The volcano becomes a way of expressing a fiery inwardness, a feeling of dissatisfaction that underlies an external pose of reticence present as a surface text.
The dialectical relationships between concealment/ostentation, inner/outer self, intensity/reticence which structure the poem are clearly presented in the chain of oxymora that starts each stanza of the poem: "A still—Volcano– Life" / "A quiet—Earthquake Style" / "The Solemn—Torrid—Symbol—". In these three lines the reader will note key words that are capitalized and isolated by dashes, which in this poem are more rhetorical than syntactic. The tension between the ambivalent or paradoxical qualities that help to describe "Life," "Style," and "Symbol" easily emerges: They are at the same time calm and volcanic, harmless and threatening, sober and fiery. On the other hand, "Volcano," "Earthquake," and "Torrid" seem to express the intense side of the inner self, an intensity that is what arouses the speaker's desire. 
If we understand the volcanic life as a metaphor for the definition of the self, we can see here the opposition between private behavior, potentially destructive, and a public pose that is socially contained. The fact that this poem is written by a woman inevitably leads the reader to find in the spatial volcanic imagery the expression of the imprisonment of nineteenth-century women: The confinement of the self to the walls of the volcano stands for the boundaries of the Victorian women—inside the walls of the house, the patriarchal culture, the codes of masculine expression and ideology.  Thus, the explosive threat that characterizes moments of escape may be the answer to the social attempt to reduce female feelings to "a domestic hearth, [that] warms but does not threaten." 
Whether a feminine I or a Dickinsonian I, the fact of the matter is that the speaker posits herself beyond the status quo. In the second stanza, despite Dickinson's strong elision, the reader can still try to read the verb "to suspect" and the preposition "[b]y" as a passive structure—"Too subtle [to be suspected by] natures." In this way, "natures" would be an indefinite passive agent whose contrasting qualities would place it at the antipodes of the speaker. But the complex depth of the speaker is nonetheless too subtly intense to be suspected by other selves. The speaker positions herself on the side of Naples, which metonymically evokes Vesuvius as well as Pompeii—the city once destroyed by this now dormant volcano. "[T]his side Naples" (with all its symbolic and thermal implications) reinforces the seismic features of the self and the assertion of the South as locus of desire. The North (geographic and imagic) is then unable to perceive the threatening inwardness—it is the society, New England, the O ther, the "not-me." 
Defining the speaker's identity in opposition to the "not-me," Dickinson draws the circumference in on herself to tighten the private space of personal consciousness.  The speaker lives not in the center but in the margins of her existence. By rejecting the center—the common knowledge—the speaker observes and tests her limitations, which paradoxically protect and fix her inner space. Therefore, we can conclude that understanding the self as circumscribed by the circumference is similar to the image of the incandescent magma inside the volcano, or the fiery self as a prisoner of social forces. Torrid but solemn, it encloses in itself the truth of life, the knowledge and spiritual power.
Moreover, "The lips that never lie—" might be the volcano's lips or, in the absence of a specific reference, the lips of a verbal and sexual power that burst truthfully. They might be the lips of a verbal eruption—a speech that deals with the human psyche—or the lips of a poet who is also feminine. The destructive potential of a woman's truth articulates an unuttered discontent because uncensored feminine expression is dangerous to the self and to society. Genital connotations let us read in the labial imagery the repressed voice, passion, anger, and power of a feminine, violently sexual volcano. In fact, the compression of the last two lines shows great evidence of this contained but ruthless power: "Whose hissing Corals part—and shut– / And Cities—ooze away—." The menacing silence that runs through the poem is now broken by the sound of the "hissing Corals," whose red color reminds us of the incandescent magma and its violent activity. Chaos sparked by the explosion is intensified by the compression and elision of the line, especially through the use of "and" to connect the nouns "Corals" and "Cities," and the verbs "part," "shut," and "ooze away."
Verbs like "part" and "shut" may indicate alternate movements of disclosing and hiding by the self. Furthermore, and along with the prepositional verb "ooze away," we might also read them as destructive actions on cities—the social, artificial spaces that are separated, destroyed, and covered by the lava. Thus, the volcano is the geological force that ruins the hillsides; it is the explosive speech that shatters the established order; it is the self who reveals its true identity despite the risk of losing its social existence. In fact, the overt expression of contained feelings will probably annihilate the circumference. Explosion will make the speaker lose not only control but also energy because, after the explosion, exhaustion is inevitable.
As a result, compression (not expansion) is the key to growth and empowerment in Dickinson's poetry. It is through repeated implosions, detonations directed inward, that she tests the limits within, sustaining the barriers that protect her from immortality, infinity, or self-destruction. Dickinson's reticent volcano is subversively impetuous. It stands for the self, the writing, and the woman. It is the overwhelming dissatisfaction that begets her poetry. Between the desire to escape, and the actual implosions, her poems are nourished by tension within and without. The implosive self is the best poetic locus for the quest of creation: It is inwards that the inciting power arises and matures into a passionate and sublime fire. And it could not be otherwise, for in Emily Dickinson's words, "Within [. . .] is so wild a place." 
(1.) In the first stanza it is the noun "Volcano," here presented as an adjective (and not the adjective "still") that suggests the idea of power and energy revealed by a closer look into the depths of the self. The power hidden in the volcano is such that eruption or explosion may destroy everything around it. Therefore, the magma flickers in the night, protecting Eros from the revealing "sight."
(2.) Sandra Gilbert and Susan Gubar draw the distinction between male and female images of imprisonment in nineteenth-century literature: One is metaphysical and metaphorical, the other social and actual. The Madwoman in the Attic: The Woman Writer and the Nineteenth-Century Literary Imagination (New Haven: Yale UP, 1979) 86.
(3.) Joanne Dobson, Dickinson and the Strategies of Reticence.
(4.) The opposition between North and South is quite common in other compositions, such as in "Our lives are Swiss—" (no. 80). In this poem, the geographical situation of Switzerland—a northern country sheltered, but also totally isolated, by the natural phenomenon of the Alps—seems to describe the speaker's own natural, still confinement. This time, the speaker posits herself in the North, since she can only glimpse at, but not reach, Italy—the other side, the promise of fulfillment anchored close to the southern side of existence.
(5.) See Jane Donahue Eberwein, Dickinson: Strategies of Limitation (Amherst: U of Massachusetts P. 1985) 161.
(6.) Emily Dickinson, letter 432 of The Letters of Emily Dickinson, ed. Thomas H. Johnson and Theodora Ward (Cambridge: Belknap Press of Harvard UP, 1958).
Dickinson, Emily. "A still—Volcano—Life—." The Complete Poems of Emily Dickinson. Ed. Thomas H. Johnson. Boston: Little, 1960.From The Explicator 58.2 (Summer 2000)
ReferencesKaren Ford - www.english.illinois.edu/maps/poets/a_f/dickinson/dickinson.htm