By Joan Faust
Among Andrew Marvell’s many poems that incorporate reflective/refractive surfaces, Eyes and Tears perhaps best illustrates Marvell’s use of the power of mirrors both to skew an image through anamorphosis and to take an anamorphic image and “correct” it in linear perspective. Marvell uses reflective surfaces in this poem to suggest not only reflection and introspection but also distortion and deception. However, here, instead of physical mirrors, Marvell presents us with human eyes, whose role in the process of sight was just being understood in the early modern period; and tears, physical excretions, the origins, purposes, and meanings of which still boggle the minds of philosophers, theologians, and, more recently, biologists. In Eyes and Tears, Marvell capitalizes not only on the philosophical and scientific knowledge of sight, mirrors, lenses, and tears, but also on the mystery of it all, particularly tears, which he presents as means of confusion, cleansing, correction, and possible deception, ironically resulting in a “a sight more true” (l. 27).
Marvell has four poems that I would judge are influenced by the early modern fascination with mirrors and reflecting/refracting surfaces: The Gallery, Mourning, On a Drop of Dew, and Eyes and Tears. And actually, the driving issues are not so much the technical advances and popular interest in the power of optics but rather Marvell’s own personal obsession with self-reflecting and self-constituting images, perhaps best discussed in Christopher Ricks’s seminal article “Its own resemblance,’” likening Marvell’s many self-reflexive figures to what William Empson terms the “self-inwoven simile” or the “short-circuited comparison,” “a figure which both reconciles and opposes, in that it describes something both as itself and as something external to it which it could not possibly be.” Ricks claims that “[w]ith a range of mood, intent, and form, Marvell uses [this self-inwoven simile] in every important kind of poem that he writes.”
Of the four poems mentioned, Eyes and Tears focuses most attention on the role of the eye in the process of sight and on the origin and purpose of tears. Most acknowledge the influence of the numerous “tear” poems appearing in the Renaissance, particularly characteristic of the Baroque style. The trend, usually called “the literature of tears,” was “a body of Counter-Reformation devotional works in both poetry and prose depicting Mary Magdalen’s remorse at her first meeting with Christ and at his tomb, and St Peter’s remorse after his betrayal.” The subject matter is treated “through extended, serial, and hyperbolical analogues, especially for tears.” The most obvious examples of this type are Southwell’s St Peter’s Complaint and Crashaw’s Sainte Mary Magdalen, or The Weeper. Though many of the “tear” poems connect tears with repentance and so prove religious in nature, Eyes and Tears prompts disagreement about its intent. Of the six Marvell poems he designates as religious, J. B. Leishman does not include Eyes and Tears. Nigel Smith more specifically affirms, “Marvell’s poem begins and remains secular in subject-matter.” However, Barbara Lewalski believes that the early placement of Eyes and Tears in the order of poems in Marvell’s 1681 posthumous Miscellaneous Poems indicates it should be considered one of the religious poems. Louis Martz questions whether Marvell’s poem is religious or “whether it is better called a witty Mannerist exercise on a religious theme, mingling cleverly the argued wit of Donne, the Baroque paradoxes of Crashaw, and the neat trim craftsmanship of Jonson.” Rather than an indication of religious fervor, then, Martz judges Marvell’s images to have “an effect of being coolly contrived, not growing out of some inevitable problem or passion, as in the better poems of Donne or Crashaw.” However, because Eyes and Tears explores the power of the mirror to correct inaccuracy of vision, and that inaccuracy can only be taken as a focus on material rather than spiritual good, any interpretation cannot reject a religious basis.
Eyes and Tears follows the pattern of Crashaw’s The Weeper in that the fourteen stanzas do not form a tight, interconnected whole but offer various emblematic images of tears, with the central stanza VIII describing Mary Magdalen, the central figure in many of the “tear” poems. However, more than Crashaw, Alabaster, and others, Marvell emphasizes the role of the eyes, with tears as their products, more than the tears themselves. Stanza 1 praises Nature in empowering the eyes “to weep and see” (l. 2) and thus able to react to “vain” objects with complaint (l. 4). The eyes’ sight is “self-deluding,” so that the eyes are agents of their own deception. The eyes do not serve as passive doorways but active “scales” (l. 10) which “weigh” each tear before releasing them in payment as “the true price of all my joys” (l. 12). The eyes sport these tears as “pendants” (l. 16) and release tears as drawn by the beauty of “the red, the white, the green” of Nature’s gardens (l. 18). The speaker commends those whose grief prompts their eyes to weep and thus, by blurring their own vision, protect themselves against the snares of the material world (ll. 25-28). Though the speaker acknowledges Magdalen’s tears in the self-inwoven image of “liquid chains” that “fetter her Redeemer’s feet” (ll. 31-32), it is her “captivating eyes” (l. 30) that produce the chains that ensnare the feet of Christ. Stanza IX praises the beauty of weeping, swollen eyes that, in stanza X, can “drench” desire and “slake” “the Thund’rer”’s wrath (ll. 37-40). Stanza XII commands the eyes to practice their “noblest use” of weeping (l. 46), an act possible only to “human eyes” (l. 48), according to the speaker (though refuted by many biologists and pet owners who claim that animals, too, can weep). In the speaker’s final images, tears only become important when they emerge from and merge with the eyes, becoming “two clouds dissolving” (l. 49), “two fountains” (l. 51) “two floods” (l. 52), until “eyes and tears be the same thing” (l. 56) in an anamorphic blur of qualities: “These weeping eyes, those seeing tears” (l. 56).
Marvell’s stress on eyes over tears is not surprising: the role of the eyes not only in sight but in insight and moral decisions has fascinated scholars in philosophy, medicine, theology, and biology for millennia. Though all senses were considered “transmitters” to the intellect and the soul, sight has always been regarded as the highest and most perfect of the senses. In the opening paragraph of his Metaphysics, Aristotle explains, “[W]e take pleasure in the senses for their own sake, and above all in the sense of sight, preferring it to all the other senses because it is the principal source of knowledge.” Similarly, in Chapter 53 of Summa Contra Gentiles, Aquinas writes that sight, “of all the senses, is the highest and most spiritual, and therefore most akin to the intellect. It is for this reason that intellectual knowledge is called sight.” The very subject introduced in stanza I, the wisdom of Nature’s decision to make eyes the source of both sight and tears, takes the reader to the liminal realm of eyes, tears, and mirrors. Physically, Mary Douglas explains, entrances and exits of the human body are, like any margin, sacred, polluting, and/or feared, depending on the situation. As doorway, the eye is in-between. Arabian philosopher Averroes (CE 1126-1198) describes the eye’s ability to comprehend the forms of things “like a mirror whose nature is intermediate between that of air and that of humour at the eye’s rear.” The eye is a Neoplatonic window of the soul and of the mind, so is a passageway from exterior to interior, as Helkiah Crooke’s Mikrokosmographia (1618) describes: “The eyes are the discoveries of the mind, as the countenance is the Image of the same; by the eyes as by a windoe, you may looke euen into the secret corners of the Soule.” Torti credits fourth century theologian Athanasius in the Contra Gentes as “the first to introduce the idea of soul as a mirror—capable, when pure, of reflecting God’s image—into Christian thought.” Socrates offered a similar idea in Plato’s I Alcibiades (c. 432 BCE) when he said that man’s knowledge of the divine was acquired by knowledge of the self. Because God created the soul to reflect his image, knowledge of one’s own soul is essential to knowledge of God. Similarly, the concept of mind as mirror, providing an accurate representation of the world, was prevalent in the seventeenth century, according to Dosia Reichardt, “refined by Descartes into an instrument of knowledge which could be made more accurate through empirical inspection.”
Augustine’s theory of perception also added the concept of the eye as a mirror of the soul, and since, as seen above, the soul is considered a mirror of God, the eye also was associated with mirroring God. In De Trinitate, Augustine differentiates the physical sensation of sight from perception. Sight occurs by means of the eye, but perception occurs, in Grabes’s summary of Augustine, “only when the soul—which is distributed over the whole body and consequently is also to be found in the eye—has by its own power created an image of the representation of an object which is accessible to the physical sense.” Thus, while the eye is the gateway to the soul, the soul actively creates an image, persisting even when the image is not there. Miles adds that the object is not only “touched” by the viewer’s active seeing; the object is actually “printed” on the soul of the viewer—the soul is “fitted together” with or “takes the shape of” the object of sight. Thus in the act of vision, the viewer and object are “momentarily united.” This concept fits nicely with the intromission theory of sight, which posits that the image seen actually enters the eye and implants itself in the mind and soul, so that sight is an actual “taking over of qualities,” making the viewer and viewed become one. (Perhaps René Maigritte had these theories in mind in his eye-mirror painting, Le faux miroir [Fig. 1] which seems to erase the boundary between viewer and viewed).
Giving scientific proof of this image formation within the eye/soul are the experiments of Father Christoph Scheiner (1575-1660), whose dissections of sheep and ox eyes proved that “rays of light entering the eye were brought together as they reached the retina, and that they formed upon it a reduced image of the external object from which it had originally been reflected.” Scheiner thus proved not only that man actually mirrored the outside world within the eye, but also that the eye could actually see itself as it functioned, enacting Marvell’s “self-inwoven” images. And because the image imprinted on the retina was an accurate picture but smaller, inverted, and reversed, Friedman concludes, “[t]he retinal image was at once a clear representation of the thing that called it into being and a distortion of that thing,” so, as in the poem, distortion presents a “sight more true.”
But what if the distortion is not correction but deception? According to Gent, the early seventeenth century shared Descartes’s fear that all we can see is false and evil:
I shall then suppose, not that God who is supremely good and the fountain of all truth, but some evil genius not less powerful than deceitful, has employed his whole energies in deceiving me; I shall consider that the heavens, the earth, colours, figures, sound, and all the other external things are nought but the illusions and dreams of which this genius has availed himself in order to lay traps for my credulity.
As Stuart Clark admits, “[I]f the senses were windows on the soul they were also doors, allowing entrance to temptation, vice, and evil spirits. The human moral citadel was continually under assault.” Gent argues that many in the early seventeenth century believed in this deceit of the senses: Hamlet and Macbeth, and other Shakespearean plays like Midsummer Night’s Dream, A Winter’s Tale, and The Tempest also explore the unreliability of the senses.
Saving the soul from “self-deluding sight” (l. 5) are the blurring tears, which, Douglas admits, unlike other bodily fluids that exit a boundary of the body, “do not defile”:
This is partly because tears are naturally pre-emptied by the symbolism of washing. Tears are like the rivers of moving water. They purify, cleanse, bathe the eyes, so how can they pollute? But more significantly tears are not related to the bodily functions of digestion or procreation. Therefore their scope for symbolizing social relations and social processes is narrower.
Flowing from the eyes and blurring the deluded (though perhaps perspectively accurate) sight in stanza II, these liminal fluids, whether prompted by complaint (stanza I), sorrow (stanza III), joy (stanza IV), pity (stanza VI), or grief (stanza VII), provide a “better measure” (l. 7) of the material world by skewing earthly snares and temptations into a self-mirroring anamorphic blur.
This concept of tears as corrective surfaces is also explored in William Alabaster’s Sonnet 71:
When without tears I look on Christ, I see Only a story of some passion, Which any common eye may wonder on; But if I look through tears Christ smiles on me. Yea, there I see myself, and from that tree He bendeth down to my devotion, And from his side the blood doth spin, whereon My heart, my mouth, mine eyes still sucking be; Like as in optick works, one thing appears In open gaze, in closer otherwise. Then since tears see the best, I ask in tears Lord, either thaw mine eyes to tears, or freeze My tears to eyes, or let my heart tears bleed, Or bring where eyes, nor tears, nor blood shall need.
Though Shell defines these “optick works” (l. 9) as the magnifying quality of lens-like tears, perhaps more accurately, Alabaster editors G. M. Story and Helen Gardner interpret the term as “probably ‘perspectives,’ or anamorphic pictures needing specific angle of view to undo distortion.” The roundness of Marvell’s and Alabaster’s tears easily links them to convex early mirrors and to those mirrors that were used to untangle an anamorphic image so popular in the seventeenth century, as I have discussed elsewhere. Among the catoptric anamorphic paintings that required a mirror to attain “a sight more true” are Holbein’s The Ambassadors (1553) (Fig. 2) and the anonymous Portrait of Charles I and its verso image Portrait of Charles II (after 1649) (Figs. 3 and 4), which required a cone or cylindrical mirror placed in the center of the painting to view. The concept of tears as mirrors relates back to the “literature of tears” genre, since condemned prisoners in the early modern period were encouraged to contemplate pictures of the Magdalen to encourage them to imitate her penitence and salvation. Magdalen was referred to as a mirror, since sinners could see their own faults in her. According to Terry, “The phrase ‘mirror of conversion’ was a common trope in popular sermons of the Magdalen.”
Are tears produced by deceiving eyes themselves trustworthy? The origin, purpose, and meaning of tears have also been disputed since ancient times. A major theory is the therapeutic effect of tears: Aristotle’s notion of catharsis from tragedy links tears to the clearing of our psyche, “in order to let rationality and our emotions have their proper place.” In the first century CE, Ovid wrote that “by weeping, we disperse our wrath…. It is a relief to weep; grief is satisfied and carried off by tears.” Fifty years later, Seneca writes, “tears ease the soul.” Henry James’s brother William wrote in his 1890 Principles of Psychology that tears produce pleasure: “There is an excitement during a crying fit which is not without a certain pungent pleasure of its own.” And modern biochemist William H. Frey provides a more a scientific thesis: “Emotional tears play a precise and central role in helping to restore the chemical balance of the body by secreting substances produced by the body in response to stress.” Since Freud’s Studies in Hysteria, psychiatrists have touted the benefits of tears in the ridding of neuroses.
And like other humors, tears have been categorized by purpose: modern biologists have found that we produce three kinds of tears: basal tears, which “bathe our eyes each time we blink,” reflex tears, which emerge as an involuntary reaction to an eye injury or exposure to strong fumes like onions or chemicals, and emotional tears, which are elicited during times of distress. Scientists can actually differentiate among these tears since each has a different chemical makeup. Walter reports that emotional tears “carry 20 to 25 percent more types of protein and have four times the amount of potassium than reflex tears, as well as 30 times the concentration of manganese than human blood serum. They are also loaded with hormones, such as adrenocorticotropin (ACTH), which humans produce when under stress, and prolactin, which controls the neurotransmitter receptors in the lacrimal glands that release tears.”
But once identified as “emotional,” the specific emotion prompting those tears remains an enigma. The early Christian Church divided tears into four types: tears of contrition, tears of sorrow, tears of gladness, and tears of grace. However, Lutz admits that often, tears result from competing causes: “fear mixed with desire, hope mixed with despair.” And, of course, tears can be deceptive, used to manipulate. Ovid was the first to recommend tears to help young men seduce women. He also suggests that women fake tears to impress or gain the sympathy of men. So do the tears shed in Marvell’s Eyes and Tears indicate true contrition? Grace? Sorrow? The uncertainty is a point perhaps best explored in Marvell’s Mourning: “But sure as oft as women weep, / It is to be supposed they grieve” (ll. 35-36).
One thing tears do accomplish is to blind us to outside distractions, as Lutz explains:
Crying allows us to turn away from the cause of our anguish and turn inward, away from the world and toward our own bodily sensations, our own feelings. Our feelings overwhelm the world, or at least our ability to process any new information from our world.
Tears accomplish this by blurring and therefore blocking the gateways to the soul. The speaker’s command to his eyes to open “your double sluice” is especially appropriate, since the word “sluice” not only refers to a dam but “a gap, breach, opening, or hole,” so a passage to another realm. The images in stanzas XII-XIV stress the lack of boundaries by likening the eyes not only to water-producing entities but to water itself—“two clouds dissolving” (l. 49), “two fountains” (l. 51), “two floods” (l. 52)—until the climax of a complete merge of eyes and tears, all boundaries dissolved, “Till eyes and tears be the same things” (l. 54). And it is the eyes’ production of these anamorphic mirrors that succeeds, by blurring, in clarifying a spiritually accurate vision, a “sight more true” (l. 27), a paradox that leaves us in an uncertain realm: “These weeping eyes, those seeing tears” (l. 56). As Clayton comments, even this “clincher” image which confirms the self-generating, self-reflecting aspects of eyes and tears raises ambiguity: “these” and “those” can be either demonstrative adjectives and/or demonstrative pronouns, the last really blurring the separation of eyes and tears: “These [tears or eyes] weeping eyes, those [eyes or tears] seeing tears.” Wilson accurately describes the final effect: “Where does reality lie? The reflections bounce back and forth until, as in the amusement park fun house, reality is no longer separable from appearance and we bump our nose on what seems like a clear passage out.”
Can a sight produced by “self-deluding” eyes and tears of uncertain motivation truly result in a “sight more true”? In leaving us in a blur, Marvell succeeds in what he does best: keeping us talking.
Southeastern Louisiana University
 All quotations from Marvell’s poems will be taken from The Poems of Andrew Marvell, ed. Nigel Smith (Harlow: Longman, 2007).
 William Empson, Seven Types of Ambiguity, 2nd rev. ed. (London: Chatto & Windus, 1947), 160-61; Christopher Ricks, “’Its own resemblance,’” in Approaches to Marvell: The York Tercentenary Lectures, ed. C. A. Patrides (London: Routledge & K. Paul, 1978), 109.
 Richard Strier, “Herbert and Tears,” ELH 46.2 (Summer 1979): 221-22.
 Smith, Poems, 50. J. B. Leishman, The Art of Marvell’s Poetry (New York: Minerva Press, 1968), 245, argues that the title of Eyes and Tears can be attributed to Shakespeare’s Venus and Adonis: “O how her eyes and tears did lend and borrow! / Her eye seen in the tears, tears in her eye, / Both crystals, where they view’d each other’s sorrow” (ll. 961-63). Other poems assumed to have influenced Marvell include Richard Crashaw’s The Weeper (1646), Richard Alabaster’s Sonnet 21 and Sonnet 71 (1597-98), Thomas Carew’s Lips and Eyes (1640), and John Donne’s A Valediction: of Weeping. Smith, Poems, 50-51.
 Those six poems Leishman classifies as religious are The Coronet, On a Drop of Dew, A Dialogue Between the Resolved Soul, and Created Pleasure, A Dialogue between the Soul and Body, Bermudas, and Musicks Empire (193). Smith does acknowledge that “stanza VIII, with the attached Latin version, is religious and certainly may be regarded as part of the English tradition inaugurated by the Elizabethan Jesuit Robert Southwell” (50). He speculates that Marvell may not have written the Latin stanza, or that perhaps the stanza began as a separate Latin epigram later incorporated into the longer poem.
 Smith, Poems, 50; Barbara Lewalski, “Marvell as Religious Poet,” in Approaches to Marvell, 251; Louis Martz, The Wit of Love: Donne, Carew, Crashaw, Marvell (South Bend, IN: University of Notre Dame Press, 1969), 163-64.
 Chip Walter, “Why Do We Cry?” Scientific American Mind 17.6 (Dec. 2006/Jan. 2007), insists, “other animals may whimper and moan, and wail, but none sheds tears of emotion—not even our closest primate cousins, whose tears cleanse the eye but are not prompted by emotion.” William Frey and Muriel Langseth, Crying: The Mystery of Tears (Minneapolis: Winston Press, 1985), Chapter 14 discusses the issue of animal tears, citing Charles Darwin and gorilla behavior expert Dian Fossey as claiming animals do cry emotional tears, but they admit more scientific evidence must emerge before a conclusion can be reached.
 Sharon Harwood-Gordon, A Study of the Theology and Imagery of Dante’s Divinia commedia: Sensory Perception, Reason, and Free Will (Lewiston, NY: The Edwin Mellon Press, 1991), 19.
 Aristotle, I.i.980a 28, lect. 1 par. 6-7, from Patrick Boyde, Perception and Passion in Dante’s Comedy (Cambridge: Cambridge University Press, 1993), 61.
 From Harwood-Gordon, Theology and Imagery, 33.
 Mary Douglas, Purity and Danger: An Analysis of Pollution and Taboo (New York: Praeger, 1966), 124.
 Averroes, from Stuart Clark, Vanities of the Eye: Vision in Early Modern European Culture (Oxford: Oxford University Press, 2007), 17; Crooke, Mikrokosmographia (1618), from Norman K. Farmer, Jr., Poets and the Visual Arts in Renaissance England (Austin: University of Texas Press, 1984), 78.
 Anna Torti, The Glass of Form: Mirroring Structures from Chaucer to Skelton (Rochester, NY: D. S. Brewer, 1991), 6; Dosia Reichardt, “Marvell’s ‘Interesting Paramour’: Clora Meets the Cavaliers in ‘The Gallery.’” Paragone 23.2 (2006): 101.
 Herbert Grabes, The Mutable Glass: Mirror-Imagery in Titles and Texts of the Middle Ages and English Renaissance, trans. Gordon Collier (Cambridge: Cambridge University Press, 1982), 83; Margaret Miles, “Vision: The Eye of the Body and the Eye of the Mind in Saint Augustine’s De Trinitate and Confessions,” Journal of Religion 63 (1983): 127-28.
 Thijs Weststeijn, “Seeing and the Transfer of Spirits in Early Modern Art Theory,” in Renaissance Theories of Vision, ed, John Shannon Hendrix and Charles H. Carman (Farnham: Ashgate, 2010), 153.
 Donald M. Friedman, “Sight and Insight in Marvell’s Poetry,” in Approaches to Marvell, 306-8. Four theories of vision prevailed in the Middle Ages—all of which agreed that both light and eyes were necessary for sight and all maintained that there must be some form of contact between the object of vision and the eye. Epicurus’s “intromission” theory argued that thin films of atoms depart from visible objects in all directions and enter the eye of the observer, communicating to the observer all of the visible qualities of the objects from which they issued. In contrast, Euclid held an “extramission” theory of vision, which posited that a visual fire emanates from the observer’s eye in the form of a cone and proceeds in straight lines unless reflected or refracted. If the cone falls on an opaque object, the object is perceived and the perception is somehow returned to the eye. In his usual conciliatory manner, Aristotle proposed a “mediumistic” theory of vision, agreeing that a visible object sends its visible qualities through the air (or other transparent medium) to the observer’s eye, but these qualities sent actually change the transparent medium, and these changes are carried to the observer’s eye, actually altering the watery substance of the eye. Therefore, a green object in some sense colors the air and the observer’s eye green, and this acquisition of color constitutes the act of seeing. The eye does not receive the visible object but actually becomes the visible object, giving a new view of Marvell’s “green thought in a green shade” (The Garden, l. 48). Latin physician Galen suggested another mediumistic view that concentrated more on the role of the eye as window to the soul, arguing that a visual spirit descended from the brain to the optic nerve to the eye, then emerged from the eye for a short distance, transforming the surrounding air which thus becomes an extension of the optic nerve and an instrument of the soul. The air itself becomes percipient, sees the object with which it is in contact, and returns its perceptions through the transformed air to the eye and the optic nerve and, ultimately, to the soul. Both Epicurus and Aristotle, then, stressed the physical aspects of sight, while Euclid’s concern was only mathematical. Galen’s mediumistic theory focused more specifically on the physiological process of sight, emphasizing the eye and optic nerve as physical accesses to the soul. For further discussion, see David C. Lindberg, “The Science of Optics,” in Science in the Middle Ages, ed. David C. Lindberg (Chicago: University of Chicago Press, 1998), 339-41.
 René Descartes, Philosophical Works 1.148, from Lucy Gent, “The Self-Cozening Eye,” Review of English Studies 34.136 (Nov. 1983): 420-21.
 Clark, Vanities of the Eye, 24; Gent, “The Self-Cozening Eye,” 421.
 Douglas, Purity and Danger, 125.
 The Sonnets of William Alabaster, ed. G. M. Story and H. Gardner (Oxford: Oxford University Press, 1959), 59.
 Alison Shell, Catholicism, Controversy, and the English Literary Imagination 1558-1660 (Cambridge: Cambridge University Press, 1999), 90; Alabaster, Sonnets, 59, n. 108.
 Joan Faust, Marvell’s Liminal Lyrics: The Space Between (Newark: University of Delaware Press, 2012).
 Allie Terry, “Criminal Vision in Early Modern Florence: Fra Angelico’s Alterpiece for ‘Il Tempio’ and the Magdalenian Gaze,” in Renaissance Theories of Vision, ed. John Shannon Hendrix and Charles H. Carman (Farnham: Ashgate, 2010), 61, n. 51.
 Tom Lutz, Crying: The Natural and Cultural History of Tears (New York: W. W. Norton, 1999), 118.
 From Lutz, Crying, 118, 41.
 Frey and Langseth, The Mystery of Tears, 12; Lutz, Crying, 120.
 Chip Walter, “Why Do We Cry?” Scientific American Mind 17.6 (Dec. 2006/Jan. 2007).
 Lutz, Crying, 26, 32, 35.
 Lutz, Crying, 25.
 Oxford English Dictionary Online, s.v. “sluice,”n. 3, accessed 18 May 2014.
 Thomas Clayton, “‘It is Marvell He Outdwells His Hour’: Some Perspectives on Marvell’s Medium,” in Tercentenary Essays in Honor of Andrew Marvell, ed. Kenneth Friedenreich (Hamden, CT: Archon Books, 1977), 66; G. R. Wilson, “The Interplay of Perception and Reflection: Mirror Imagery in Donne’s Poetry,” SEL 1500-1900 9 (Winter 1969): 120.