Anne Rouhette Elizabeth

Anne Rouhette

Keywords: Mary Shelley, Frankenstein, physiognomy, transparency, femininity, epistemology Mary Shelley, Frankenstein, physiognomonie, transparence, féminité, épistémologie

published or not. The documents may come

Elizabeth Lavenza in Frankenstein (II):

"The image of her mind" (1818) and most strikingly with the monster. According to this epistemological model, if

Elizabeth's loveliness corresponds to her moral worth, then it follows that the monster's hideous appearance would be the sign of a vicious mind. Yet, as any reader of Frankenstein knows, the correspondence or non-correspondence between the monster's physical appearance and his moral attributes invites considerable scepticism and encourages us to regard the epistemological model at work here with a critical distance that is both doubtful of Victor's assumptions and liable to problematize the act of reading, whether it be of texts or of the faces represented within them, that the model implies.

In this second part, I will argue that this model which determines the flawed character of Victor's perception is linked to a certain conception of femininity prevalent at Shelley's time; what I will suggest is that Frankenstein engages with the demand for transparency upon which this faulty conception relies and problematizes it yet stops short of wholly rejecting it.

Frankenstein and physiognomical interpretation

Although an interest in physiognomy can be traced in the 18 th century English novel, its success in Shelley's time is largely due to the popularity of the theories of Johann Caspar Lavater (1775-78), "practically a household name in Britain from the moment in 1789 when the first English translation of his Essays on Physiognomy appeared" (Tytler 293) up to the early 1810s. When the future Mary Shelley, born in 1797, was nineteen days old, her father asked his friend William Nicholson, a chemist and disciple of Lavater, to perform a physiognomic reading on his daughter. In the report preserved among William Godwin's papers, Nicholson wrote that he saw "considerable memory and intelligence […] quick sensibility," concluding: "her manner may be petulant in resistance, but cannot be sullen" (Sunstein 22). According to John Graham, the tendency to consider physiognomy as a science waned after the 1780s, but although Godwin himself was no enthusiastic follower of the face-reading Swiss pastor, Lavater had his devotees among Godwin's circle, among whom Thomas Holcroft, and Shelley's father also claimed as late as 1831, the year that Frankenstein was revised, that "nothing can be more certain than that there is a science of physiognomy" (cited in Graham 568). Godwin's interest finds its way into the descriptions of his own fictional characters, for instance in the portrait he draws of Marguerite in St Leon which will be briefly discussed below. As for Mary Wollstonecraft, she translated and abridged Lavater's Physiognomische Fragmente zur Beförderung der Menschenkenntnis und Menschenliebe in 1788 "with the liveliest interest" (cited in Graham 567) and met the author when he visited London in 1792. Wollstonecraft's position wavered, however; she expressed doubts about the soundness of Lavater's principles and methods, quipping in Letters Written during a Short Residence in Sweden, Norway and Denmark (1796) that Lavater must have found "lines in [Count Bernstorff's] face to prove him a statesman of the first order; because he has a knack at seeing a great character in the countenances of men in exalted stations, who have noticed him, or his works" (179).

Whether or not Godwin, Wollstonecraft, Edgeworth, Lewis and others completely endorsed the principles on which Lavater based his analyses, "[e]ach of these writers used interpretations of facial details in presenting their fictional characters, indicating their absorption of a point of view sympathetic with that of Lavater" .

It is thus not unreasonable to assume that Mary Shelley inherited an ambivalent vision of physiognomy from her parents. Furthermore, the success of Lavater's physiognomic treatise coincided with and contributed to the development of the novel of sensibility in the late 18 th century, where meaning is conveyed by the body rather than by language, facial expressions being given pride of place 3 . The first decades of the 19 th century pursued this exploration of the correspondence between the sensible and the spiritual, often formulated in terms of the relationship between the "inside" and the "outside" of the human body, with the publication of novels such as Sense and Sensibility by Austen and Frankenstein, in which Shelley echoes her parents' conflicting stance towards physiognomy and explores the dangers as well as the appeal of this approach. Time and again, the dangers of judging a situation on the "face" of it are underlined in Frankenstein. Justine is sentenced to death because of her behaviour and of false evidence while Victor finds himself wrongly accused of Clerval's murder because of appearances: "they observed that it appeared that I had brought the body from another place, and it was likely, that as I did not appear to know the shore, I might have put into the harbour […]" (126, emphasis added). Situations prove misleading, and so may faces: Victor reconsiders his physiognomic interpretation of M. Krempe, overcoming his initial distrust and separating Krempe's "repulsive" appearance from his character. In Krempe's case, Victor distinguishes between inside and outside: "I found even in M.

Krempe a great deal of sound sense and real information, combined, it is true, with a repulsive physiognomy and manners, but not on that account the less valuable" (30).

Victor here applies caution, although belatedly, as recommended by Lavater who advocated critical distance. No such distance benefits his creature though. As Scott J.

Juengel observes, quoting Lavater, "Victor's interpretations of the creature's countenance are invariably consistent with the most fundamental of physiognomical tenets, that 'beauty and deformity of the countenance is in a just and determinate proportion to the moral beauty and deformity of the man'" (360). Whereas Victor's first impression of Krempe was belied by a better acquaintance with him, his first impression of the creature, which fills him with "breathless horror and disgust", serves as an unalterable basis for all ulterior readings of his behaviour. When Victor sees "one hand […] stretched out," he interprets this gesture as made "seemingly to detain [him]" (36), so as threatening since he runs away -the adverb "seemingly" making explicit the fact that Victor interprets the monster's appearance. Nowhere in the novel will he revise this judgment or envisage that he may have misread this gesture or his creature's face. As we know, the monster's account of himself differs, and so may the reader's, who can interpret this outstretched hand for instance as an infant's reaching out to the "father" that Victor, after all, purported to be. Victor reacts like everyone else on seeing the monster, that is, according to the latter, on a prejudice (or judgment formed a priori): they are prejudiced against me. I have good dispositions; my life has been hitherto harmless, and, in some degree, beneficial; but a fatal prejudice clouds their eyes, and where they ought to see a feeling and kind friend, they behold only a detestable monster. (93) Plainly, according to the monster, his "inside", or moral sensibility, does not match his "outside", or physical appearance. So why is Victor able eventually to see through Krempe's "repulsive" face but not to read correctly the creature he has fashioned? In the next part of this essay, I would like to take up an analogy frequently made by critics that the creature is but a "woman in disguise" (Gilbert and Gubar 237) and suggest that behind the monster, Shelley examines a certain representation of femininity in her society and in fiction.

Physiognomy, women and Elizabeth Lavenza

The ideology of physiognomic correspondence finds its way into the fictional representations of the 18 th and 19 th centuries with various aims and effects, concerning both male and female characters. Smollett's Roderick Random possesses flaming red hair which matches all too well his fiery personality, for instance. In Frankenstein, Victor's thoughts and emotions can be visible on his face, as when "Elizabeth read [his] anguish in [his] countenance" (63). But the construction in the course of the 18 th century of the morally transparent body as an ethical constraint on women rendered this a particularly crucial issue for them and affected the descriptions of female characters. This process, started well before the publication of Lavater's theories, was already explored for instance in Burney's Evelina (1778), but during the lifetime of Mary Wollstonecraft and in that of her daughter4 , the success of physiognomy must have buttressed what rested hitherto on an ideological and religious basis. Sentences like this one, from James Fordyce's Sermons to Young Women (1766) This breach of her most sacred law [chastity], the justice of Nature has generally branded with a look and manner particularly characteristic and significant; as, on the other side, she has always (I think, always) marked the genuine feelings of modesty with a look and manner no less correspondent and impressive (I 50), or this: "Having no bad passions to conceal, your thoughts and manners will be transparent" (II 145), from the same source, must have taken on an additional meaning; the advice and guidelines given in the many conduct books of the period, whose weight on female writers is analysed in particular by Mary , received a scientific veneer which arguably made their message even more difficult to resist. The presentation of female characters, particularly in female-authored novels, bears witness to this difficulty. Such is the case with the description of Elizabeth Lavenza in 1818, or rather with the two descriptions provided in part I, which do not rest on quite the same epistemological premises. The second one works in the traditional manner of Lavater's physiognomy (and of conduct books), from the outside to the inside, from the physical trait to the intellectual one which it signifies: "An open and capacious forehead gave indications of a good understanding, joined to great frankness of disposition. Her eyes were hazel, and expressive of mildness" (51). Limited to a surface reading, this passage, which is reminiscent of what we saw regarding 1831 Elizabeth in part I, focuses on "indications" and "expression" that are signs but no assurance of a "good understanding," "frankness" and "mildness". Here Victor limits his description to the surface, never telling us (or rather Walton) what Elizabeth's personality is really like.

Since this is a retrospective narrative, and since, besides, Victor has been acquainted with Elizabeth since childhood, he is supposed to be well aware of Elizabeth's character: he should not have to read on the surface what he already knows, all the more so as this jars with the sense of depth conveyed by the first description of Elizabeth in 1818 (excerpt A in Part I). Short as it is, this first portrait stands out when compared to the heroines of previous novels, especially male-authored, in the sense that Shelley has Victor present his cousin from the inside out. Victor begins by portraying Elizabeth's moral and intellectual worth ("docile," "good-tempered," "playful,"

with "strong and deep feelings," etc.) before turning to her appearance with the sentence "[h]er person was the image of her mind". Elizabeth's "person" confirms what he knows of her "mind," it does not signify it, or not only. Instead of appraising her personality based on her appearance, he finds confirmation in her looks of what he knows of her character; to put it differently, his knowledge of Elizabeth's feelings and understanding comes before his account of her face, in the way he presents it, working from the depths to the surface, if I may use this metaphor. This reverses the order of presentation found in many novels, where "appearance" precedes "essence," even in the case of characters supposedly known to the narrator. The first introduction of Fielding's Sophia Western by the omniscient narrator of Tom Jones begins with "the outside of Sophia," shifting to the inside a few paragraphs later with a phrase whose wording almost literally reverses Shelley's: "[h]er mind was every way equal to her person" (136). Closer chronologically to Frankenstein's Elizabeth, another omniscient narrator, that of Scott's Waverley (1814), concludes Flora McIvor's physical description with the following sentence: "[h]er sentiments corresponded with the expression of her countenance" (107), before moving to the depiction of said sentiments. Or again, in St Leon (1799), which Shelley had re-read in 1814 and again in 1815, Godwin's firstperson narrator describes his future wife thus 5 : Marguerite Louise Isabeau de Damville was, at the period of our first meeting, in the nineteenth year of her age. Her complexion was of the most perfect transparency, her eyes black and sparkling, and her eyebrows dark and long. Such were the perfect smoothness and clearness of her skin, that at nineteen she appeared five years younger than she was, and she long retained this extreme 5 For a thorough analysis of the role played by physiognomy in Godwin's fiction, see Scott J. Juengel, "Godwin, Lavater, and the Pleasures of Surface", Studies in Romanticism 35, n° 1 (Spring, 1996), 73-97. Of course my choice of male authors and of novels here may seem limited and biased. Nevertheless they are fairly representative of works read and sometimes re-read by Shelley shortly before or during the conception and writing of Frankenstein (St Leon and Waverley, two novels which greatly influenced her) or no doubt read by her during her childhood or early teenage years; Godwin had called Tom Jones "one of the most admirable performances in the world" in "Of English Style" (The Enquirer, 1797 [462]). According to the Shelleys' reading list, Mary Shelley had read (most probably reread) Amelia in 1817. Incidentally, Sophia Western may very well be an inspiration for Shelley's Eastern Safie, both characters being dark-haired, dark-eyed orphans who escape their tyrannical fathers' commands to join the all-worthy man they love. juvenility of form. Her step was airy and light as that of a young fawn, yet at the same time firm, and indicative of strength of body and vigour of mind. Her voice, like the whole of her external appearance, was expressive of undesigning, I had almost said childish, simplicity. Yet, with all this playfulness of appearance, her understanding was bold and correct. Her mind was well furnished with every thing that could add to her accomplishments as a wife or a mother. […] (33-34) The purity of her mind seemed to give a celestial brilliancy and softness to the beauties of her person. (35) The "transparency" of the "celestial" Marguerite's complexion functions as the visible sign of her purity; having no "bad passions to conceal," her "thoughts and manners" are transparent, to paraphrase Fordyce.

I would like to suggest that in this respect, Shelley has Victor describe Elizabeth, in this first passage at least, in a manner which corresponds better with the logic found in certain contemporary female authors when presenting similarly transparent characters, although her reading list does not include them. Here is Adeline in Ann Radcliffe's Romance of the Forest (1791):

The observations and general behaviour of Adeline already bespoke a good understanding and an amiable heart, but she had yet moreshe had genius. She was now in her nineteenth year; her figure of the middling size, and turned to the most exquisite proportion; her hair was dark auburn, her eyes blue, and whether they sparkled with intelligence, or melted with tenderness, they were equally attractive: her form had the airy lightness of a nymph, and, when she smiled, her countenance might have been drawn for the younger sister of Hebe: the captivations of her beauty were heightened by the grace and simplicity of her manners, and confirmed by the intrinsic value of a heart "That might be shrin'd in crystal, And have all its movements scann'd." (29).

The narrative voice moves from an estimate of Adeline's character, based on her behaviour to Madame de La Motte in the previous paragraph, to direct characterization of her mind ("she had genius") to a description of her physical appearance, before returning to the "intrinsic value" of a heart which "confirm[s]" Adeline's beauty: the outside confirms the inside and vice-versa. The unidentified quotation resorts to the image of the crystal and its transparency to highlight the heroine's purity and the perfect correspondence of her mind and body.

Mind and body correspond but are completely separated in the case of Jane Austen's ironically transparent Marianne Dashwood 6 . Her disposition is described at the end of the first chapter of Sense and Sensibility (1811): "She was sensible and clever; […] generous, amiable, interesting" (6), some thirty pages before her physical appearance in Chapter X:

Her form, though not so correct as her sister's, in having the advantage of height, was more striking; and her face was so lovely, that when in the common cant of praise, she was called a beautiful girl, truth was less violently outraged than usually happens. Her skin was very brown, but, from its transparency, her complexion was uncommonly brilliant; her features were all good; her smile was sweet and attractive; and in her eyes, which were very dark, there was a life, a spirit, an eagerness, which could hardly be seen without delight. (35)(36) This portrait seems included as an afterthought, merely to explain the impression made by Marianne on Willoughby while the distance between the description of inside and outside in effect breaks the link between them, even though the character is endowed with "transparent" skin. among other things thanks to the shift between the literal and the metaphorical registers). With his visible arteries, the monster's complexion grotesquely evokes a desirable feature in a woman's appearance which Lovelace for instance dwells on in his description of "this lady is all glowing, all charming flesh and blood; yet so clear, that every meandring vein is to be seen in all the lovely parts of her which custom permits to be visible" (399, emphasis added). Precisely because of its transparency, the monster's hideous surface prevents potential interpreters from accessing his inside, from reading him properly; they all stop at the outside, with the obvious exception of the blind De Lacey. Frankenstein thus questions the very basis on which

Victor's knowledge rests. Far from allowing one access to the inside, to the depths, the surface becomes an obstacle when reading it is posited as the only mode of access to truth, largely because the subjectivity of the interpreter, his or her prejudices, may not be taken into accounta pre-determined interpretation thus being understood as objective. Once again, the monster literalizes what remains metaphorical for the other characters, here especially Victor: when he looks into a "transparent pool", he views not the depths of the pool, not its bottom, but the reflection of himself on the "mirror"like surface (78). The image of the mirror makes clear the risk of seeing one's self in the other, and it does so, in this seminal passage of the novel, at the very moment when self-awareness begins, when subjectivity is constituted, revealing that it is built into human beings' access to the world. Physiognomists obviously run the same risk.

Analysing the physiognomical readings performed by the virtuous heroes of sentimental novels, Barbara Benedict draws the following conclusion: "[b]oth physiognomists and sentimental heroes see virtuously because they see naively: locked in a Lacanian mirror stage, they see themselves in the other" (320). The facereader, from this perspective, can only see himself or herself in the other's countenance, consciously or not, just as the text-reader may be tempted to interpret a novel based on his or her mind-set; the mirror suggests that it is his own ugliness which

Victor sees in the monster.

Is it his own virtue that he sees in Elizabeth then? The failure of Victor's reading of his creature does not necessarily entail that the legibility of the human body is an illusion or that a correspondence between outside and inside may never exist; nothing in the novel leads us to that his interpretation of Elizabeth's character is incorrect, or for that matter that Elizabeth is wrong when reading anguish in Victor's countenance in the excerpt quoted above. Because of the many links uniting the monster and Elizabeth, it does however question the stress on feminine transparency so prevalent at Shelley's time in literature and in society, which appears so often in conduct books and in the description of idealized female characters like Godwin's Marguerite because, as in the 1831 version of Elizabeth, it amounts to a denial of the human characteristics associated with a sense of depth, feelings, understanding etc.

If the monster really is a female in disguise, then by implication there is nothing beneath the surface and no need for Victor to reconsider his first judgment, as he does with Krempe. The difference between the two brief descriptions of Elizabeth mentioned above may help us understand the extent of Shelley's critique. When Victor sees Elizabeth as a "playfellow," "a friend," a "companion," a "future wife" only in a distant future, his depiction of her mingles surface and depth (20). But when he returns home after six years at Ingolstadt, the "girl" has become a "woman," a very possible bride in a very near future (53). Victor's focus on the surface in his second reading of Elizabeth can be said to be motivated by his fear of female desire, obvious in the dream in which Elizabeth's warm body becomes his mother's corpse or when he tears the female monster's body to pieces; this has been the subject of many feminist readings of the novel. Beyond Victor, it is her society's reduction of women to surfaces that Shelley questions by showing the dramatic consequences that may result from it. The superficiality of a woman's upbringing was denounced in particular by Mary Wollstonecraft, who explained how the stress on a woman's appearance led that woman to become mere surface: "Taught from their infancy, that beauty is woman's sceptre, the mind shapes itself to the body" (Vindication 58) 8 . Victor's impossibility of going beyond his interpretation of the monster's surface, his refusal to allow that there might be a beautiful inside behind the horrible outside makes blatantly visible, on a literal level, what women were confronted with in Shelley's time and the dangers and potential destructiveness of such an approach to the feminine for men and women alike. Working from another starting-point, Joyce Zonana reaches a similar conclusion:

Because he is regarded as pure flesh, the monster's fate is comparable to that of women in patriarchal society: no matter how hard he tries, his status as 'creature' blinds his creator (and all other humans who can see) to his status as 'rational being'" (176) 9 .

However pertinent and convincing this analysis may be, it does not account for the ambiguous manner in which the access to knowledge through physiognomy is represented; Frankenstein does not contain simply a criticism of the cult of transparency and of its face-reading preachers, if only because, as mentioned above,

Victor seems to be right in his assessment of Elizabeth's character (at least, nothing contradicts it within the diegesis). In the last part of this essay, I would like to examine the appeal that such an approach may have for a Romantic writer like Shelley.

Paradise Lost

Frankenstein exposes the attempt at equating "inside" and "outside," at seeking for a perfect correspondence between what one shows and what one thinks or feels as dangerous and destructive ideology. Yet physiognomy also represents an ideal in several respects, and it seems to me that its appeal lingers on in the novel. First, it pretends to offer a world of meaning and community, a hermeneutic system where with the requisite skill and a little caution, the interpreter supposedly possesses a key to understand others and to connect with them, since he or she also has human features which in turn may be read. As Barbara Benedict explains, "[t]he reciprocity of […] physiognomist and face […] suggests a world of ideal unity and legibility" (323). This unity is also that of the individual human being, who thus finds a way out of the dichotomy which opposes matter and spirit; the utopia of "a morally transparent anatomy" (Juengel 357) so prevalent in the 18 th century 10 rests on a doctrine postulating the unity of the human being, a fundamental coherence, a connectedness between body and soul. Beyond, it postulates coherence between words and reality, 9 In this respect, these conclusions are close to those reached by Peter Brooks in his highly influential essay "What is a Monster?". Adopting a psycho-analytical approach and insisting on completely different elements in the novel, notably the creation of the monster as a mother substitute, he wonders if "the Monster is not in fact a woman who is seeking to escape from the feminine condition into recognition by the fraternity" and speculates on "Mary Shelley's attempts to escape the generic and cultural codes that make heroines into objects to be looked at" (218). to assert that Shelley simply rejects the dream of transparency and the ideal of unity it relies on, a Romantic ideal where opposites can be reconciled, like the world Walton dreams of, where "the seat of frost and desolation" that is the pole can be converted into "the region of beauty and delight" (7), or a world where the boundaries between life and death would be "ideal," i.e. imaginary, as in Victor's visions (33). Of course, such an ideal is destructive: several members of Walton's crew die and the Frankenstein family is nearly annihilated. But its ultimate attraction lies in its claim to unite human beings to the divine. That Lavater should have been a pastor is no coincidence; he was looking for God in human faces and devised a system relying on "a faith in the sign, the unity of signifier and signified12 , God and man, appearance and reality" (Benedict 312). In other words, he was looking for a lost paradise, the place where, as Jean Starobinski explains in his work on Rousseau, "c'était la transparence réciproque des consciences, la communication totale et confiante" (19). For many writers of the late 18 th and early 19 th century, however aware they may have been that they did not live in such a world, that quest found its embodiment in the transparent female character. The vision of woman constructed in the course of the 18 th century, that of a child-like being who can retain that child-like transparency, a dream of immediacy that 1831 Elizabeth, in her celestial simplicity, embodies more than her predecessor, testifies to the lingering power of that myth. That this type of character usually met with an untimely death shows how conscious those writers were of the lethal character of the transparency myth, but that did not prevent them from being attracted to Lavater's theories, as we saw above, perhaps precisely for no other reason than to debunk them.

It seems to me that the 1831 text provides a more damning condemnation of this myth and of the epistemological process it relies on because its Elizabeth, limited to a mere mirror-like surface, reflects whatever Victor wishes to see. The sense of depth in the portrait of 1818 Elizabeth, however fleeting, hints at a different approach and begs the question that sophisticated readers may scoff at: if Elizabeth's person is "the image of her mind," could the same be said for the creature's? Is Victor's reading of the creature really erroneous? After all, the monster is the ultimate unreliable narrator. We literally only have his word for it that he helped the De Laceys (how could Safie and Felix's letters prove that?) or saved a young girl13 . We are led to believe him because of his eloquence, but what prevents us from seeing him, for instance, as a forebear of Frederick Clegg in Fowles ' The Collector (1963), making up excuses for himself, pleading the purity of his intentions and blaming society for his isolation while kidnapping and letting a young woman die? If we confront his words with his actions, what emerges is that he murdered a young boy and framed an innocent woman, thereby condemning her to death. He relates that his first action was to steal food from a poor old man (72-73), while his last act before venturing on the Arctic sea was to "carr[y] off their store of winter food" from villagers and steal their dogs (148). What if the features selected by Victor for his creature were really "beautiful" (35), but the monster's evil mind shone through them? As readers, we are confronted with two possible types of interpretation. In the first one, we are to take everything at "face value", transparently: the monster's person is ugly because his mind is ugly. In the second one, opacity reigns and nothing can be taken for what it seems. Because they rely on completely opposed epistemological modes, the two interpretations should be mutually exclusive and yet they co-exist in the novel. This partly accounts for the

  , whose face, as ThomasDutoit points out, is "opaque" (853). But this opacity is an ironical one since "[h]is yellow skin scarcely covered the work of muscles and arteries beneath" (35). His literally transparent skin is the first trait mentioned in Victor's famous description of his creature, and it echoes Elizabeth's metaphorical one a few pages before (we saw in part I how closely the monster and Elizabeth are connected,

	Furthermore, despite her transparency, Marianne Dashwood long remains a
	mystery to her sister and to the reader since it is impossible to know whether or not
	she is engaged to Willoughby until the novel is more than half way through. Austen
	articulates a dialectics between the opacity and the transparency of her female
	protagonist which greatly resembles what Shelley does with her monster in
	Frankenstein 7 . It might seem paradoxical to speak of transparency with regard to the

No ethereal creature belonging to a different species like 1831 Elizabeth, Austen's lively and dark-eyed heroine also shares 1818 Elizabeth's "strong and deep" feelings (20) and sharply problematizes the cost of transparency, since the correspondence between her feelings and her bodyshe makes a point of showing what she feelsleads her to the brink of death. In fact, from Richardson's Clarissa to the early 19 th century, transparency has become a trope used by novelists such as Burney, Austen or Shelley to describe a certain type of female characters who have an unfortunate tendency to die young; Elizabeth Lavenza comes after a long series of heroines, often, like Godwin's Marguerite, similarly ill-fated. Even a survivor like Sophia

Western in a comic novel is indirectly but explicitly linked with death since Fielding's narrator resorts to a few lines taken from an elegy, Donne's "Elegy on Mistress Elizabeth Drury," to describe Sophia's metaphorical transparency: "Her pure and eloquent blood/ Spoke in her cheeks, and so distinctly wrought/ That one might almost say her body thought" (135). 7 I am not suggesting that Shelley was in any way directly influenced by Austen since to my knowledge there exists no trace of her reading Sense and Sensibility or Pride and Prejudice (1813), whose first title was "First Impressions" and which interrogates the role played by subjectivity in knowledge of the other. Rather, I wish to point out that the intellectual and cultural climate of the 1810s has led the two main female novelists of the decade to explore and to some extent denounce the "transparency myth". creature

  when Victor insistsin vain, which should alert us to the flawed nature of his system -on the "connected" aspect of his story to the magistrate (142). It thus professes to offer a world of truth where deceit would be impossible; looking at a person, male or female, would suffice to know exactly who he or she is, in terms of identity and of character, as is the case with Burney's Evelina, the living image of her mother, or with Richard of York in Perkin Warbeck, who asks a gypsy to "read" him": "read my palm; read rather my features, and learn indeed who I am", i.e. the son of Edward IV and another doomed transparent character in Shelley's fiction (187)11 . Transparency is a fundamentally ethical stance according to which appearance should correspond to essence, a stance which Austen's erring but sometimes admirable Marianne chooses in defiance of the hypocritical world she lives in. Austen certainly denounces Marianne's standpoint and the character serves as a counterexample, but the profound ambiguities of Sense and Sensibility and its notoriously unsatisfactory ending make this a difficult position to maintain unequivocally. It would be just as difficult in my view

10

Barbara Stafford calls physiognomy "the 'universal science' of the Enlightenment" (quoted by Juengel 354). See Barbara Maria Stafford, Body Criticism: Imagining the Unseen in Enlightenment Art and Medicine, Cambridge, Mass.:

MIT Press, 1991.

as

As William St Clair rather bluntly but aptly puts it, "women were a problem in Britain throughout the revolutionary and romantic period" (506).

Austen was very probably aware (and wary) of Lavater's theories, according to Graeme Tytler (307), which arguably plays a role in her presentation of Marianne.

For an analysis of the "tremendous extent to which […] social, moral and biological taxonomies are shaped by aesthetic principles" in Frankenstein, seeHeymans (119).

On the analogy between palmistry and physiognomical seeBenedict 316.

For two different and stimulating approaches to the linguistic aspect of transparency (or lack thereof), seeBrooks 1978 and Cross.

Lipking states the case for or against the monster and Victor very wittily and convincingly (420-421), concluding with Mary Shelley's deliberate ambiguity, "the courage of her lack of conviction" (433).


Miloš Burger
email: milosb@ff.bg.ac.rs

Jörg Hermann

Stark broadening measurements in plasmas produced by laser ablation of hydrogen containing compounds

Keywords: Stark broadening, Spectra simulation, Hydrogen, Calcium, LIBS

We present a method for the measurement of Stark broadening parameters of atomic and ionic spectral lines based on laser ablation of hydrogen containing compounds. Therefore, plume emission spectra, recorded with an echelle spectrometer coupled to a gated detector, were compared to the spectral radiance of a plasma in local thermal equilibrium. Producing material ablation with ultraviolet nanosecond laser pulses in argon at near atmospheric pressure, the recordings take advantage of the spatially uniform distributions of electron density and temperature within the ablated vapor. By changing the delay between laser pulse and detector gate, the electron density could be varied by more than two orders of magnitude while the temperature was altered in the range from 6,000 to 14,000 K. The Stark broadening parameters of transitions were derived from their simultaneous observation with the hydrogen Balmer alpha line. In addition, assuming a linear increase of Stark widths and shifts with electron density for non-hydrogenic lines, our measurements indicate a change of the Stark broadening-dependence of H α over the considered electron density range. The presented results obtained for hydrated calcium sulfate (CaSO 4 •2H 2 O) can be extended to any kind of hydrogen containing compounds.

Introduction

Stark broadening of spectral lines is under investigation since the discovery of the effect in 1913. With the diversification of the available plasma sources and the increasing interest for plasma diagnostic tools, the theoretical and experimental studies dedicated to Stark broadening became popular in the 1960's [1,2]. Since that time, several review papers have been published to summarize the results obtained by a large number of research groups all over the world [3][4][5][6][7]. Despite of the numerous efforts in the past decades, precise Stark broadening parameters are still only partially available, even for the most prominent transitions. This is mainly due to the difficulties of calibrating the Stark broadening measurements using an alternative and independent measurement method. Recently, Thomson scattering was applied to measure electron density and temperature in laser-produced plasmas [8,9]. However, the application of this method to high-density thermal plasmas feature favors the establishment of local thermal equilibrium [START_REF] Eliezer | Generalized valid-510 ity condition for local thermodynamic-equilibrium in a laser-511 produced plasma[END_REF][START_REF] Cristoforetti | Thermodynamic equi-513 librium states in laser-induced plasmas: From the general case to 514 laser-induced breakdown spectroscopy plasmas[END_REF].

The expansion dynamics of plasmas produced by laser ablation strongly depend on the irradiation conditions and the surrounding atmosphere. The use of infrared radiation favors the absorption of laser photons by the background gas, leading to an elongated shape of the plasma [START_REF] Boueri | 517 Early stage expansion and time-resolved spectral emission of 518 laser-induced plasma from polymer[END_REF]. This condition enables rapid intermixing of the ablated vapor with the surrounding atmosphere [START_REF] Ma | Ultraviolet versus infrared: Effects of ablation laser 522 wavelength on the expansion of laser-induced plasma into one-523 atmosphere argon gas[END_REF]. Contrarily, the use of shorter wavelength radiation increases the laser-material energy coupling. The plasma screening effect [START_REF] Mihailescu | Laser-plasma interactions[END_REF][START_REF] Burger | Shielding effects 528 in the laser-generated copper plasma under reduced pressures of 529 He atmosphere[END_REF] is reduced, and the plasma is characterized by a hemispherical shape [START_REF] Mercadier | Diagnostics 532 of nonuniform plasmas for elemental analysis via laser-induced 533 breakdown spectroscopy: demonstration on carbon-based mate-534[END_REF].

If, in addition to the use of the short laser wavelength, the ablation process occurs in an argon atmosphere, the ablation plume appears spatially almost uniform. This was illustrated by the analysis of the spectral shapes of resonance lines and strongly Stark-shifted transitions [START_REF] Hermann | Comparative 536 investigation of laser ablation plumes in air and argon by anal-537 ysis of spectral line shapes: Insights on calibration-free laser-538 induced breakdown spectroscopy[END_REF].

Stark broadening parameters of calcium lines are of interest to laboratory plasma diagnostics, as well as for theoretical modeling. In LIBS plasmas for example, Ca is often present as an impurity. Also, due to its large abundance all over the universe, calcium presents a constituent of many stellar plasmas, and Ca and Ca + lines are of a great importance in astrophysics [START_REF] Dimitrijević | Stark broadening of neu-541 tral calcium spectral lines[END_REF].

The most intense lines and in particular the ionic resonance lines were investigated extensively in the past [START_REF] Chapelle | Experimental and theoretical 544 electron impact broadening of some Mg II and Ca II lines of 545 astrophysical interest[END_REF][START_REF] Hildum | Stark broadening of calcium ion reso-547 nance lines[END_REF][START_REF] Purić | Stark shifts of some isolated spectral lines 549 of singly ionized earth alkaline metals[END_REF][START_REF] Jones | Measure-552 ment and calculation of the Stark-broadening parameters for the 553 resonance lines of singly ionized calcium and magnesium[END_REF][START_REF] Kusch | Broadening and shift of calcium lines 556 by microfields[END_REF][START_REF] Hühn | Broadening and shift of calcium lines by 558 van der Waals interaction with argon atoms and by electron im-559 pact[END_REF][START_REF] Hadžiomerspahić | Stark 561 broadening and shift of some isolated spectral lines of singly 562 ionised earth alkaline metals[END_REF][START_REF] Baur | A shock tube study of line broadening 564 in a temperature range of 6100 to 8300 K[END_REF][START_REF] Fleurier | Stark profiles of some 567 ion lines of alkaline earth elements[END_REF][START_REF] Goldbach | Stark-570 width measurements of singly ionized calcium resonance lines 571 in a wall-stabilized arc[END_REF][START_REF] Srećković | Measured Stark width and shift of 573 393.367 nm Ca II resonance spectral line[END_REF][START_REF] Aguilera | Measurement of Stark 576 widths and shifts of Ca II spectral lines[END_REF]. The resonance lines are generally strongly self-absorbed, and their practical usage for plasma diagnostics is often doubtful. Stark broadening calculations, based on the semiclassical perturbation formalism, have been performed for many Ca [START_REF] Dimitrijević | Stark broadening of neu-541 tral calcium spectral lines[END_REF][START_REF] Dimitrijević | Stark broadening parame-579 ter tables for neutral calcium spectral lines[END_REF] and Ca + transitions [START_REF] Dimitrijević | Stark broadening parame-582 ter tables for Ca II lines of astrophysical interest[END_REF][START_REF] Dimitrijević | Stark broadening of Ca 585 II spectral lines[END_REF]. The correlation of Stark broadening with the energy gap between the upper-level of the transition and the ionization potential was also investigated [START_REF] Tapalaga | Stark 588 width regularities within neutral calcium spectral series[END_REF].

However, Stark parameters of many Ca transitions in the visible and UV ranges are still missing in literature.

In the present work, we take advantage of the spatially uniform character of the plasma produced by UV nanosecond laser ablation in argon at near atmospheric pressure. Samples of hydrated calcium sulfate were ablated to obtain spectral line emission from hydrogen, calcium, oxygen and several impurities. Comparing the measured emission spectrum to the spectral radiance computed for a uniform plasma in local thermodynamic equilibrium, we were able to characterize the plasma and to deduce the Stark broadening parameters for many atomic and ionic lines. With respect to the traditional methods based on space-resolved spectroscopic measurements and complex data analysis via Abel inversion [START_REF] Chapelle | Experimental and theoretical 544 electron impact broadening of some Mg II and Ca II lines of 545 astrophysical interest[END_REF][START_REF] Fleurier | Stark profiles of some 567 ion lines of alkaline earth elements[END_REF][START_REF] Cirisan | Stark broadening measurement of Al II lines in a 592 laser-induced plasma[END_REF], the presented method appears eas-ier to handle and gives rapid access to a large number 95 of data. Indeed, using an echelle spectrometer of large 96 resolving power, the recording of a few spectra at dif- with the gas is negligible, and the laser spot diameter is 124 small compared to the plasma radius. In that case, the 125 blast wave model may be applied to describe the plume 126 expansion dynamics. The conditions are fulfilled for ul-127 traviolet nanosecond laser pulses [START_REF] Boueri | 517 Early stage expansion and time-resolved spectral emission of 518 laser-induced plasma from polymer[END_REF][START_REF] Mercadier | Diagnostics 532 of nonuniform plasmas for elemental analysis via laser-induced 533 breakdown spectroscopy: demonstration on carbon-based mate-534[END_REF]. If argon is 128 used as a buffer gas, the spatial distributions of electron 129 density and temperature within the ablated vapor are al-130 most uniform and the spectral radiance of the plasma 131 can be calculated using [START_REF] Gerhard | Quantitative 596 analyses of glass via laser-induced breakdown spectroscopy in 597 argon[END_REF] 132 The Stark width is obtained using [START_REF] Griem | Stark broadening of the hydrogen Balmer-α line in 507 low and high density plasmas[END_REF][START_REF] Tognoni | From sample to signal in laser-induced breakdown spec-606 troscopy: a complex route to quantitative analysis[END_REF] 151 The spectra were recorded for different delays of the detector gate t g with respect to the laser pulse. The gate width ∆t g was adjusted for each delay so that ∆t g < t g .

I λ = U λ (1 -e -αL ), (1
∆λ S tark = w       n e n re f e       m , (3)
We denote the measurement time t = t g ± ∆t g /2. To enhance the signal-to-noise ratio, data acquisition was performed by averaging over 500 ablation events, applying 5 pulses to 100 different irradiation sites. The sites were separated by a distance of 150 µm. of 10 for that part of the spectrum. The plasma emission is dominated by spectral lines of singly charged calcium ions. In addition, transitions of Ca neutral atoms and of species from several impurity elements are observed.

Results and discussion

Plasma characterization

We identify the strongly broadened H α transition in the red range of the spectrum. The atomic fractions of both major and minor elements deduced from the best agreement between measured and computed spectra are given in Table 1.

The spectrum measured for t = (475 ± 75) ns (see Fig. 2) is displayed in Fig. 3 for several spectral ranges, together with the computed spectral radiance. We spatially non-uniform plasma [START_REF] Hermann | Comparative 536 investigation of laser ablation plumes in air and argon by anal-537 ysis of spectral line shapes: Insights on calibration-free laser-538 induced breakdown spectroscopy[END_REF]. Here, the symmetric shape observed for the Mg I 285.21 nm line (c) shows that the plasma is spatially uniform in agreement with 3 × 10 15 cm -3 , whereas the temperature diminishes from about 14,000 to 6,000 K.

Stark width and shift measurements

The strong variation of electron density over the measured time-interval and the spatially uniform character of the laser-produced plasma are now explored to measure the Stark widths and shifts of spectral lines. We emphasize that the calculation of the spectral radiance allows us to predict the optical thickness of each transition, and thus to exclude strongly self-absorbed lines from the analysis. For some transitions such as resonance lines of neutral atoms, the optical thickness critically depends on the observation delay. At early time, when the plasma temperature is high and ionic species dominate (see Fig. 1), the ground state population num-334 ber densities of neutral atoms are small and their reso- The transition between both regimes corresponds to a 360 delay ≈ 1000 ns for which the electron density is close 361 to 1 × 10 17 cm -3 . We thus describe Stark broadening 362 of H α using Eq. (3) with w = 1.10 nm according to lit-363 erature [START_REF] Gigosos | Computer sim-611 ulated Balmer-alpha, -beta, and -gamma Stark line profiles for 612 non-equilibrium plasma diagnostics[END_REF][START_REF] Konjević | Hydrogen Balmer lines for low electron density plasma diagnostics[END_REF] and m = 0.7 or m = 0.9 for electron 364 densities below or above n re f e = 1 × 10 17 cm -3 , respec-365 tively. It is noted that the expression equals that pro-366 posed by Gigosos et al. [START_REF] Gigosos | Computer sim-611 ulated Balmer-alpha, -beta, and -gamma Stark line profiles for 612 non-equilibrium plasma diagnostics[END_REF] and Konjevic et al. [START_REF] Konjević | Hydrogen Balmer lines for low electron density plasma diagnostics[END_REF] 367 for n e < 1 × 10 17 cm -3 whereas it differs at larger elec-

97

  ferent delays enables the determination of Stark broad-98 ening parameters of a large number of spectral lines.

99 2 .

 2 Method and calculation details 100 2.1. Principle of Stark broadening measurements 101 The method for the measurement of Stark broaden-102 ing parameters consists of the following three succes-103 sive steps: (i) the plasma temperature T , the electron 104 density n e , and the relative fractions of elements C were 105 deduced for spectra recorded at different times (delay 106 between laser pulse and detector gate) using the itera-107 tive procedure decribed in Ref. [37]. Here, n e is de-108 duced from H α for which accurate electron density mea-109 surements are expected for n e -values of the order of 110 10 17 cm -3 [10]; (ii) Once the plasma is characterized, 111 the Stark widths and shifts of non-hydrogenic lines are 112 deduced from best agreement between measured and 113 computed spectra. The plasma being characterized pre-114 viously, the calculation of the line profiles accounts 115 for Doppler-and resonance broadening; (iii) The Stark 116 broadening parameters w and d of the non-hydrogenic 117 lines were deduced from the linear increase of Stark 118 width and shift with n e . 119 2.2. Calculation details 120 Material ablation with pulsed lasers in a background 121 gas at near atmospheric pressure leads to almost hemi-122 spherical expansion if the interaction of the laser beam 123

152 where w

  is the Stark width at the reference electron den-153 sity n re f e . The Stark shift is obtained from Eq. (3) replac-154 ing w by the Stark shift at the reference electron den-155 sity d. We assumed linear dependence of Stark width 156 with electron density (m = 1) for all non-hydrogenic 157 lines. For the H α transition, different m-values were 158 reported in literature. The values obtained from the-159 ory vary from 0.68 to 0.83 whereas m ≈ 0.35 was re-160 ported for experiments [10]. In the present work, we 161 use for n e ≤ 1 × 10 17 cm -3 the expression proposed by 162 Gigosos et al. [40], using Eq. (3) with w = 1.10 nm, 163 n re f e = 1 × 1017 cm -3 , and m = 0.68. For larger electron 164 densities, we use a slightly different expression with 165 a somewhat larger experimentally determined m-value 166 (see section 4.2). We stress that Stark broadening of H α 167 is recognized as a reliable tool for n e -measurements in 168 laser-induced plasmas [41]. 169 The lower level population number density in Eq. (2) is 170 obtained by calculating the plasma composition assum-171 ing local thermodynamic equilibrium (LTE) [42]. The number densities of plasma species computed for LTE 173 are displayed in Fig. 1 for the elemental composition 174 of the here investigated hydrated calcium sulfate sam-175 ple. The calculations have been performed by setting 176 the kinetic pressure of the plasma to atmospheric pres-177 sure [42]. As the pressure is kept constant, the atomic 178 number densities of elements and thus the total atomic 179 number density of the plasma decrease with increasing 180 temperature. 181 In the considered temperature range, atomic and ionic 182 species dominate the plasma composition. Molecular 183 species significantly contribute to the plasma composi-184 tion only for T < 5, 000 K. According to the moderate 185 dissociation energies of the involved diatomic species 186 [43], their number densities decrease rapidly with tem-187 perature, representing a fraction < 1% for T = 6, 000 K. 188 For T ≤ 15, 000 K, neutral atoms are the dominat-189 ing plasma species according to the large ionization po-190 tentials of the most abundant elements H and O [44]. 191 The ionization potential of Ca being of only 6 eV, the 192 electrons originate essentially from the ionization of 193 calcium in the temperature range up to 9,000 K. For 194 T > 9, 000 K, the ionization of sulfur contributes signif-195 icantly to the plasma ionization whereas T > 12, 000 K 196 is required to enable strong contributions of oxygen and 197 hydrogen. The temperature dependence of the Ca 2+ 198 number density is similar to those of O + and H + . This is 199 due to the ionization potential of Ca + that is close to the 200 ionization energies of O and H. For T > 15, 000 K, the 201 ionic species dominate the plasma and O + and H + ions 202 are the most abundant species.203 3. Experiment 204 The experiments were carried out with a frequency-205 quadrupled Nd:YAG laser (Quantel, model Brilliant) 206 delivering pulses of 4 ns duration and 40 mJ energy 207 at the wavelength of 266 nm. The laser pulse energy 208 was attenuated to 6 mJ by turning the beam polarization 209 with the aid of a half-wave plate and crossing through 210 a polarization analyzer. The laser beam was focused 211 onto the sample surface using a plano-convex lens of 212 150 mm focal length. According to a spot diameter of 213 100 µm of the Gaussian beam, a laser fluence of about 214 80 J cm -2 was obtained on the sample surface. The 215 pellet samples were prepared from commercially avail-216 able hydrated calcium sulfate powder using a hydraulic 217 press, and placed on a motorized sample holder in a 218 vacuum chamber of 10 -4 Pa residual pressure. During 219 the experiments, the chamber was filled with argon at 220 5 × 10 4 Pa pressure. The plasma emission was captured 221 by imaging the plume with two lenses of 150 and 35 222 mm focal lengths onto the entrance of an optical fiber of 600 µm diameter. The optical axis of the lenses was tilted by 15 • with respect to the surface normal. According to the image magnification of about 1:5, a cylindrical volume of about 3 mm diameter was observed. The fiber was coupled to the entrance of an echelle spectrometer (LTB, model Aryelle Butterfly) of 0.4 m focal length and a resolving power of 8.9 × 10 3 . Photon detection was ensured using an intensified charge-coupled device matrix detector (Andor, model IStar). The spectral resolution of the apparatus was measured using a low-pressure argon-mercury lamp. An intensity calibration of the spectroscopic apparatus was performed in the visible and UV spectral ranges using a calibrated tungsten lamp (Oriel, model 63358) and a deuterium lamp (Heraeus, model DO544J), respectively.

Figure 2 :Figure 3 :

 23 Figure 2: Spectrum recorded during ablation of hydrated calcium sulfate for t = (475 ± 75) ns.

  observe a good agreement between measured and computed spectral shapes for all presented transitions. It is shown that the lines are significantly broadened. Some transitions such as Ca II 370.6 nm (a) and Ca I 646.26 nm (d) are characterized by large Stark shifts. A slight difference in intensity is visible for some lines and in particular for Ca I 430.3 nm. The mismatch is attributed to the low accuracy of the transition probabilities [44]. The time-evolution of the laser-induced plasma was investigated by recording spectra for different observation delays with respect to the laser pulse. The characteristic behavior is illustrated in Fig. 4 where the spectral shapes of H α (a), Ca I 585.74 nm (b), and Mg I 285.21 nm (c) are shown for different times. We observe strong broadening at early times followed by consecutive narrowing of the line profiles with increasing time. In addition, Ca I 585.74 nm and Mg I 285.21 nm exhibit large red-shifting at early times. Transitions of large Stark shift are characterized by asymmetric line shapes if they are emitted from a

Figure 4 :

 4 Figure 4: Measured (black line) and computed (red line) spectral radiance of several transitions for different observation times.

Figure 5 :

 5 Figure 5: Saha-Boltzmann plots of calcium for various observation times.

15 Figure 6 :

 156 Figure 6: Temporal evolution of electron density (a) and excitation temperature (b). The dashed red line (b) stands for the minimum n evalue required for LTE according to the McWhirter criterion [47].

335Figure 7 :

 7 Figure 7: Stark shift vs Stark width of calcium lines deduced from measurements at various delays.

Fig. 8

 8 Fig. 8 two slightly different slopes, indicating that the 357

  359

368

  tron densities by the m-value exclusively. According to 369 the good agreement between measured and computed 370 Stark widths for n e ≈ 1 × 10 17 cm -3 reported in litera-371 ture [10] (see section 2) we estimate the uncertainty to 372 10% for n e -values close to n re f e . The error increases with distance from the reference electron density due to 374 the uncertainty of m. 375 376 4.3. Determination of Stark broadening parameters 377 After the implementation of the electron density 378 measurement procedure using H α , we explore now 379 the linear dependence of Stark widths and shifts on 380 n e for non-hydrogenic transitions to determine their 381 Stark broadening parameters w and d. Therefore, the 382 Stark widths and shifts of non-hydrogenic transitions 383 were measured for the spectra recorded with different 384 delays and and plotted as functions of electron density 385 as shown in Fig. 9. According to the precise linear 386 increase, the relative errors arising from the linear

Figure 9 :

 9 Figure 9: Stark widths of Ca I and Ca II transitions vs electron density.

  )

			1×10 19
		-3 ) Number density (cm	1×10 14 1×10 15 1×10 16 1×10 17 1×10 18	H SH	O 2	O S CaS Ca + Ca CaO	S	+	Ca 2+	O S +	2+	N e	H	+
			1×10 13	5000 SO		10000 OH	15000				20000 O 2+
							Temperature (K)
		Figure 1: Number densities of species versus temperature computed
		for a CaSO 4 •2H 2 O plasma in LTE at atmospheric pressure.
	140	velocity, k is the Boltzmann constant, f lu and n l are the
	141	absorption oscillator strength and the lower level pop-
	142	ulation number density of the transition, respectively.
	143	The normalized line profile P(λ) is calculated consider-
	144	ing Doppler and Stark broadening that are the dominant
	145	mechanisms of spectral line broadening in strongly ion-
	146	ized laser-produced plasmas [38]. Depending on the rel-
	147	ative values of Doppler and Stark widths, the line shapes
	148	are described by Gaussian, Lorentzian or Voigt profiles.
	149	The Doppler width is calculated according to plasma
		temperature and atomic mass of the emitting species.
														133
														134	where U λ is the black-body spectral radiance, L is the
														135	plasma diameter along the observation direction, and α
														136	is the absorption coefficient given by [1]
														137	α(λ) = πr 0 λ 2 f lu n l P(λ) 1 -e -hc/λkT .	(2)
														138	Here, r 0 is the classical electron radius, λ is the wave-
														139	length, h is the Planck constant, c is the vacuum light
														2

150

Table 1 :

 1 Atomic fractions of the constituents of the hydrated calcium sulphate pellet deduced from the LIBS spectra C LIBS . The reference values C re f correspond to the chemical formula CaSO 4 •2H 2 O.

			Spectral radiance (arb. units)	5 10 15 20 25 30	Ca I 649.38 nm	Ca I 649.96 nm	H	1250 ns 475 ns measured computed (a) 350 ns
							6000 ns
				0
						652	656	660
				24
							(b)
			Spectral radiance (arb. units)	4 8 12 16 20	Ca I 585.74 nm 350 ns 475 ns 1250 ns 6000 ns
				0
						584	586	588
							(c)
			Spectral radiance (arb. units)	4 8 12	225 ns Mg I 285.21 nm 350 ns 475 ns
					1250 ns
				0
					285.0		285.2	285.4
							Wavelength (nm)
	Elmnt. C LIBS (%) C re f (%)
	Ca	9.1	8.3
	S	8.3	8.3
	O	47	50.0
	H	35	33.3
	Cu	0.04	-
	Fe	0.014	-
	Li	0.017	-
	Mg	0.4	-
	Si	0.08	-
	Sr	0.012	-

  Bulajic et al. [46]. It is

				Ca I 422.67	Ca I 612.22
						Ca I 616.22
			4			Ca I 643.91 Ca I 649.38	Ca II 393.37
								Ca II 396.85
				Ca I 410.85
			0							Ca II 315.89
										Ca II 317.93
	)
	g	u	-4	Ca I 430.25 Ca I 442.67	Ca I 657.27
	/A	ul	-8	Ca I 558.87 Ca I 445.48 Ca I 443.48
	ln (		-12	350 ns 475 ns
				1250 ns
			-16	2500 ns 6000 ns			Ca II 370.69 Ca II 373.69	Ca II 500.15 Ca II 502.00
				2	4	6	8	10	12	14	16	18
						Upper level energy (eV)
										301

Table 2 :

 2 Figure 8: Stark width of a non-hydrogenic transition vs H α Stark width. We deduce slightly different m-values for H α Stark broadening (see Eq.3) for the n e -ranges below and above 1 × 10 17 cm -3 . Wavelength λ, configuration and term of upper and lower excitation levels of transitions according to NIST[START_REF] Kramida | Nist Atomic Spec-626 tra Database[END_REF]. The measured Stark width w and shift d and the values reported in literature w lit and d lit are given for n e = 1 × 10 17 cm -3 . ∆w/w and ∆d/d are the relative errors of the measured Stark width and shift, respectively. Ref.[START_REF] Aguilera | Measurement of Stark 576 widths and shifts of Ca II spectral lines[END_REF], c Ref.[START_REF] Fleurier | Stark profiles of some 567 ion lines of alkaline earth elements[END_REF], d Ref.[START_REF] Kusch | Broadening and shift of calcium lines 556 by microfields[END_REF].

						225 ns
						350 ns
		Ca I 585.7 nm Stark width (pm)	6000 ns	700 ns 900 ns 1250 ns 1750 ns 2500 ns m 0.7	500 ns	9
				H	Stark width (pm)
	388	analysis are small compared to the absolute errors
	389	associated to the electron density measurement using
	390	H α . Thus, for isolated lines of measurable Stark width
	391	over a large n e -range, the errors of the deduced w-and
	392	d-values are close to those of the most accurate n e -
	393	measurements, evaluated to about 15%. For transitions
	394	having measurable Stark width in a restricted n e -range
	395	only, the measurement errors of w and d are naturally
	396	larger.
	397
	398	The deduced broadening parameters are presented in
	399	Tables 2 and 3 for the spectral lines of calcium and other
	400	elements, respectively. Assuming an accuracy of elec-
	401	tron density measurements of about 15% for n e -values
	402	close to 10 17 cm -3 , the estimated w-measurement error
	403	ranges from 20 to 30% for most transitions. For some
	404	lines, the accuracy is lower due to larger contributions
	405	of apparatus-and/or resonance broadening to the line
	406	profile. Compared to Stark broadening parameters re-
	407	ported in literature (see last two columns in the Tables),
	408	a mismatch larger than the estimated accuracy is ob-
	409	served for several lines. Depending on the multiplet,
	410	the values reported in literature are larger or smaller
	411	than the broadening parameters we report here. The
	412	large dispersion w-and d-values measured in different
	413	experiments is attributed to two main causes: (i) the
	414	uncertainty of electron density due to the difficulties of
	415	calibrating the n e -measurements. Indeed, absolute val-
	416	ues of electron density are exclusively obtained through
	417	the calculation of Stark broadening parameters leading
	418	to a large variability of n e that depends on the chosen

Table 3 :

 3 Wavelength λ, configuration and term of upper and lower excitation levels of transitions according to NIST[START_REF] Kramida | Nist Atomic Spec-626 tra Database[END_REF]. The measured Stark width w and shift d and the values reported in literature w lit and d lit are given for n e = 1 × 10 17 cm -3 . ∆w/w and ∆d/d are the relative errors of the measured Stark width and shift, respectively. Ref.[START_REF] Djeniže | The C I 247.8561 nm resonance line stark broadening parameters[END_REF], f Ref.[START_REF] Skočić | Stark broadening in the laser-induced Cu I and Cu II spectra[END_REF], g Ref.[START_REF] Djeniže | Stark broadening and transition probability ratios in the Mg I spectrum[END_REF], h Ref.[START_REF] Bukvić | Mg II h and k lines Stark parameters[END_REF], i Ref.[START_REF] Djeniže | Mg II spectral line broadening in helium, oxygen and argon-helium plasmas[END_REF], j Ref.[START_REF] Bukvić | Line broadening in the Si I, Si II, Si III, and Si IV spectra in the helium plasma[END_REF], k Ref.[START_REF] Aragón | Measurement of Stark broadening parameters of Fe II and Ni II spectral lines by laser induced breakdown spectroscopy using fused glass samples[END_REF], l Ref.[START_REF] Aragón | Stark width measurements of Fe II lines with wavelengths in the range 260-300 nm[END_REF].

	Species	λ	Lower level		Upper level		w	∆w/w	d	∆d/d	w lit	d lit
		(nm)	Config.	Term Config.	Term (pm)	(%)	(pm)	(%)	(pm) (pm)
	C I	247.856 2s 2 2p 2	1 S	3s 2 2p3s	3 P o	14	30	8		6.8 e	2.6 e
	Cu II	212.604 3d 9 ( 2 D)4s	3 D	3d 9 ( 2 D)4p	3 F o	6	30	1.1		8.2 f	-
		213.598
	Mg I	277.669 3s3p	3 P o	3p 2	3 P	7	40	1	100	-	-
		277.827
		278.141
		278.297
	Mg I	285.212 2p 6 3s 2	1 S	3s3p	1 P o	17	30	8.5		-	-
	Mg I	382.935 3s3p	3 P o	3s3d	3 D	270	20	-45		110 g	-2 g
		383.230
		383.829
	Mg I	516.732 3s3p	1 P o	3s4s	3 S	90	20	50		33 g	9 g
		517.268									35.5 g	8.4 g
		518.360									35 g	7.4 g
	Mg II	279.077 2p 6 3p	2 P o	2p 6 3d	2 D	30	20	9		162 h	22 h
		279.799									144 h	19 h
	Mg II	292.863 2p 6 3p	2 P o	2p 6 4s	2 S	50	20	23		29 i	57 i
		293.651									30 i	68 i
	Si I	250.689 3s 2 3p 2	3 P	3s 2 3p4s	3 P o	14	25	8		14.1 j	-
		251.431									11.2 j
		251.611									11.7 j
		251.920									11.2 j
		252.410									10.4 j
		252.850									10.7 j
	Fe II	238.203 3d 6 ( 5 D)4s	a 6 D 3d 6 ( 5 D)4p	z 6 F o	5	30	2		-	-
		238.862
		239.562
		239.924
		240.488
		241.051
	Fe II	259.587 3d 6 ( 5 D)4s	a 6 D 3d 6 ( 5 D)4p	z 6 D o	6	30	0.8		-	-
		259.836
		259.939									4.5 k	-
		260.708
		261.187
		261.382
	Fe II	273.954 3d 6 ( 5 D)4s	a 4 D 3d 6 ( 5 D)4p	z 4 D o	9	30	3		5.3 l	-
	O I	777.194 2s 2 2p 3 ( 4 S o )3s 5 S o	2s 2 2p 3 ( 4 S o )3p 5 P	105	35	15		-	-
		777.416
		777.538
	Sr II	407.770 4p 6 5s	2 S	4p 6 5p	2 P o	41	20	-3.4		-	-
		421.551

e

ements by their simultaneous observation with the H α 450 transition. By varying the delay of the detector gate with 451 respect to the laser pulse, the electron density was var-452 ied by more than two orders of magnitude from 3 × 10 15 453 to 5 × 10 17 cm -3 whereas temperature was changed 454 from about 6,000 to 14,000 K. Assuming a linear in-