"Gold" as element and "gold" as substance — as conceived by Mendeleev

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[This is a guest post by Conal Boyce]

Your wonderful arabesque on the world of 'kedi'* (and the disappearance of cats for a time — perhaps to a different planet, because they had grown weary of trying to school us humans?) reminded me that you are a connoisseur of languages plural, not just Chinese. In that connection, you might find my 2019 article** on Mendeleev interesting.

[**"Mendeleev’s Elemental Ontology and Its Philosophical Renditions in German and English", HYLE – International Journal for Philosophy of Chemistry, Vol. 25 (2019), No. 1, 49-70.]

Mendeleev had a crystal clear understanding of the distinction between 'gold' as an abstract element and 'gold' as a substance held in the hand, and he even used words for those concepts that should have been readily exportable out of Russia to another country: элемент for 'element' and вещество for 'substance'. Simple, eh? But through a 150-year 'telephone game' in academia, involving slovenly 'translations' from Russian to English, Russian to German, German to English, and UK English to American English, his clear idea was gradually ground down into a kind of unrecognizable mush, until a certain professor at Georgetown U.*** recently reinvented Mendeleev's wheel, using obscenely inappropriate English words (including the obscenity 'basic substance' instead of 'element'), and even attributing the very idea itself to Kant of all people, presumably because of something about 'duality'. Strange but true.

[***Earley, J.E. Sr.: 2009, ‘How chemistry shifts horizons: Element, substance, and the essential’, Foundations of Chemistry, 11, 65-77.

In principle, a Telephone Game sounds simple to describe, but my article is tortuous because I know how ossified the Establishment is, and how unreceptive to this kind of exposé it will be unless one documents everything in excruciating detail. Accordingly, I bought $500 worth of Philosophy of Chemistry books, and educated myself on the lexicon of that field, and let the HYLE editors guide me on all the right names to drop, so that I would appear to be a card-carrying member of the club. Otherwise, no one would listen. All-told the project burned up 5 months of 18-hour days last year. Although chemistry is my second career (or vocation)****, it's not that I even cared that much about the scientific aspect of this particular project; rather, it was the linguistic travesty (and philosophical mess) that I found outrageous, and crying out to be addressed at long last. We're all aware of many aggravating aspects of the internet, but there is one thing at least that is very welcome about it:  in this internet age, academic hacks can no longer hide behind a linguistic smoke screen, confident that the mysteries of, say, Russian-to-German translation, will keep their shoddy work from being discovered!

[****Conal's Ph.D. was in Chinese literature and music.]


Here are the Abstract and Keywords of Conal's article in HYLE:

Abstract: We contrast two facets of elemental ontology, one so straightforward that it can be taught as the adjunct to a grade-school chemistry demonstration, the other involving eight decades of discourse at the graduate-school level. To explore the latter, we begin by critiquing the Lavoisier / Mendeleev relation as presented by Fritz Paneth in 1931 in German. Following the 2003 reissue of Paneth 1962 (an English translation), one observes a gradual shift such that Paneth seems the source of the substance / element distinction that was drawn by Mendeleev in 1869. Eventually, in 2009, a certain wheel is reinvented: Mendeleev’s. We advocate that the focus be returned, overtly, to Mendeleev, and to two of his words in particular, substance (веществo) and element (элемент). When suitably framed, those two words alone capture the essence of his elemental ontology.

Keywords: Mendeleev, elemental ontology, abstract element, basic substance, Grundstoff.


Selected readings


  1. ycx said,

    July 27, 2020 @ 9:22 am

    As a PhD biochemist with an amateur interest (read: zero training) in linguistics and philosophy, I'm not sure whether I see the purpose of exclusively using the two Mendeleevian concepts of "element" and "substance" in the modern day in a professional manner. The distinction between the concepts (but not the words themselves) could probably be used more effectively in a pedagogical manner.

    Modern day chemistry has advanced to the point that we now know exactly what types of atoms are present in any given substance, down to the exact isotopic ratios. Accordingly, we now know that that pure gold "substance" is made up of atoms all containing 79 protons metallic-bonded to each other. This has led to the modern definition changing to the point that an element as defined by IUPAC encompasses both the Mendeleevian "element" and "substance". https://goldbook.iupac.org/terms/view/C01022

    Modern usage of "element" can therefore refer to either the Mendeleevian "substance" or "element", and the specific meaning can be inferred from context easily as a professional in the field. I do agree that it may be more helpful in a pedagogical sense to explain the two historic meanings to further reduce the risk of misunderstanding the two concepts, but the two concepts are so inextricably linked at this point that it's no longer helpful to distinguish them as different words.

    Also, the Mendeleevian "substance" also has multiple issues that stem from its coining in the 19th century, to no fault of Mendeleev. There is no consideration of allotropic compounds (graphite, nanotubes, fullerenes, diamond) since all of these allotropes would be considered "carbon substance" with no clear way to distinguish them.

    I think the article is missing the central point of the Earley 2009 paper, which is that the advance of understanding of chemistry has led to a shift in the usage of terms from their original meanings, and the meanings are likely to continue shifting as new discoveries are made. The change is therefore every bit as expected as linguistic shifts. It's the exact opposite of the claim being made in the article that the "establishment" is ossified. To the contrary, the linguistic usage of the words has shifted significantly with improvements in our understanding of chemistry.

    The article reads more to me like someone criticising the use of the word "literally" figuratively on an online forum, complete with over-the-top tirades.

  2. Scott P. said,

    July 27, 2020 @ 12:04 pm

    Accordingly, we now know that that pure gold "substance" is made up of atoms all containing 79 protons metallic-bonded to each other.

    Isn't this part of the distinction Mendeleev was trying to make? A lump of gold will not be made up entirely of atoms with 79 protons. There will always be impurities.

  3. Victor Mair said,

    July 27, 2020 @ 12:22 pm

    From Peter Golden:

    Very interesting. However, as one whose last brush with academic chemistry was sometime around 1961, there is nothing of substance (there is that word again) that I can say. Russ. золото going back to Old ( Church) Slavonic злато, is found in virtually all of the Slavic languages (e.g. Belarus. золата, Ukr. золото, Bulg. злато, Czech zlato, Polish złoto [ pronounced zwoto] etc.). It denotes the substance, the element (abstract) etc. and is sometimes used as a praiseful descriptive, e.g. человек он — золото (as a person he is gold). The adj. золотой “golden” is used in virtually all the senses that it is used in English. Золотистый denotes “goldish, with a golden coloring.”

  4. Victor Mair said,

    July 27, 2020 @ 12:42 pm

    A note from the author of the HYLE article that is mentioned in the LL guest post dated 27 July 2020:

    The referenced article appears in HYLE under the following title: "Mendeleev's Elemental Ontology and Its Philosophical Renditions in German and English." Its original title, the one that the journal editor talked me out of, was this: "How Mendeleev met the black-box challenge of HgO formation/dissociation, with a look at long-standing translation issues, resolved via Russian, French and German primary sources." Anyway, given that the burden of the article was thus to unravel some thorny, 150-year-old linguistic issues, I made an effort to avoid going down a certain rabbit hole, along the following lines, which came immediately to mind for Victor Mair when I mentioned the article: On learning of Mendeleev's use of 'red mercury' for his ontological meditation, we think next of Lavoisier's "roasting of the calx of mercury" (which releases the 'O' in HgO), which in turn invokes the world of western alchemy (especially since Lavoisier used a retort!), which brings us in turn to eastern alchemy, so that we students of Chinese language and literature are brought home to the mystique of dānshā 丹砂; cinnabar (= mercury sulfide, HgS); the many uses and connotations of 'vermillion red'; and perhaps even A Dream of Red Pavilions. I say there are two kinds of people in the world: Those who are entranced-for-life by a single glimpse of a certain reddish-orange powder 'turning into' mercury in a heated test tube, and those who say, "Yes, I now see a silvery substance in the test tube; and the point is…?"

  5. Conal said,

    July 27, 2020 @ 1:18 pm

    ycx remarks that "Mendeleevian 'substance' also has multiple issues that stem from its coining in the 19th century, to no fault of Mendeleev. There is no consideration of allotropic compounds (graphite, nanotubes, fullerenes, diamond) since all of these allotropes would be considered 'carbon substance' with no clear way to distinguish them."

    This tells me that ycx is quite unfamiliar with Mendeleev's writings, since Mendeleev himself makes repeated references to precisely the carbon/graphite/diamond distinction (granted that he didn't know about fullerenes of course!)

    As for ycx's idea that context tells us which 'modern' meaning of the word 'element' is intended ('element' or 'substance'), that quite misses the point of the article. Moreover, his idea is contradicted by the way that Earley, Mahootian, Ruthenberg, Scerri, et al. use the term 'substance': they absolutely do not trust the context to clarify its meaning, and instead always specify 'BASIC substance' versus 'SIMPLE substance' (needlessly ugly terms that correspond to Mendeleev's 'element' vs 'substance'). If we want to talk about 'context', the place to mention context would be in connection with the symbol 'Hg' since it encompasses both the abstract element mercury AND any instance of tangible liquid mercury — for ever — until resolved by context. That's the philosophical point, which is as true today as it was in Mendeleev's time.

  6. Victor Mair said,

    July 27, 2020 @ 2:32 pm

    From Conal Boyce:

    The first comment, by 'ycx', reminded me that there is both a linguistic side and a philosophical side to the discussion.

    He goes immediately to what he believes the 'modern' usage is, linguistically, as if that is the only topic to address and clarify.

    In many lengthy exchanges on a different forum, one that is composed mainly of Periodic Table geeks, I've noticed how odd it is that many people do not even realize that there IS a philosophical issue here — the idea of an element as something abstract and eternal, something 'out there' in the cosmos that exists with or without being named by us humans and studied in a test tube. Some people immediately understand this philosophical aspect of The Periodic Table of Elements, while others, whose whole life has been spent in chemistry, seem curiously blind to it as a topic, and need to be led to it, step by step, like a horse to water — which might still not be imbibed at the river bank!

    From his remarks, I suspect that 'ycx' might be one of those who does not even see what the philosophical side of the discussion is.

    In contrast, for Joachim Schummer, founder and editor of HYLE, it is all about big-P Philosophy, and that was one reason he didn't like my title, and proposed a rather academic sounding title instead for the article, one that would downplay the technical and linguistic aspects of the article, while pointing up the aspects that would appeal to his professional-philosopher type colleagues in Europe.

    No doubt there are parallels you can see, that I don't see, between you and Joachim Schummer — as founders of journals that have both linguistic and philosophical facets to them.

    (Informally speaking, one may say that the Philosophy of Chemistry field has two founders, Joachim Schummer in Karlsruhe, Germany, and Eric Scerri at UCLA, both around the same time — in the mid 1990s I think it was. Schummer made it hard as hell to get my MS 'acceptable' in his eyes, i.e., looking like it was written by a card-carrying professional philosopher-of-chemistry, but I guess the 5 months of 'torment' was worth it.)

  7. A1987dM said,

    July 27, 2020 @ 2:41 pm

    @ycx: two allotropes are the same element but arguably different substances.

  8. Chris Button said,

    July 27, 2020 @ 5:08 pm

    Any insights into the etymology of oranges :)


  9. Bill Benzon said,

    July 28, 2020 @ 6:51 am

    Wonderful (I think). I have a long-standing interest in ontological conception and have used "NaCl" and "salt" as an example. In middle school science we learn that they are the same, which comes as something of a revelation. But, alas, they aren't quite the same. As I say in an article I published some years ago in the Handbook of Metphysics and Ontology*:

    In everyday life steel bars and window panes are solid objects. For the scientist, the glass of the window pane is a liquid, and the solidity of both the window pane and the steel bar is illusory, since the space they occupy consists mostly of empty regions between the sub-atomic particles which constitute these objects. These facts, however, have no bearing on the ontological categories of common sense. Sub-atomic particles and solid liquids do not exist in the domain of common sense. Common sense employs different ontological categories from those used in the various specialized disciplines of science.

    Similar examples of differences between common sense and scientific ontologies can be multiplied at will. The common sense world recognizes salt, which is defined in terms of its colour, shape, and, above all, taste. But the chemist deals with sodium chloride, a molecule consisting of sodium and chlorine atoms; taste has no existence in this world. To common sense, human beings are ontologically distinct from animals; we have language and reason, animals do not. To the biologist there is no such distinction; human beings are animals; language and reason evolved because they have survival value. Finally, consider the Morning Star and the Evening Star. Only by moving from the domain of common sense to the domain of astronomy can we assert that these stars are not stars at all, but simply different manifestations of the planet Venus.

    In all of these cases the common sense world is organized in terms of one set of object categories, predicates, and events while the scientific accounts of the same phenomena are organized by different concepts. In his seminal discussion of natural kinds, Quine suggested that science evolves by replacing a biologically innate quality space, which gives rise to natural kinds (in our terms, the categories of a common sense ontology), with new quality spaces. However, Quine has little to say about just how scientific ontology evolved from common sense ontology.

    *Hans Burkhardt and Barry Smith, eds. Handbook of Metaphysics and Ontology, Muenchen: Philosophia Verlag GmbH, 1991, pp. 159-161.

  10. Bill Benzon said,

    July 28, 2020 @ 7:41 am

    BTW, as you likely know, commentary about GPT-3 has been burning up a certain part of the Twitterverse. I've been reading a bit about it, and even staged a competition between GPT-3 and Marcus Christian (an African-American poet) on sonnet writing – think of it as an up-dating of the John Henry story. I wonder how GPT-3 does on the substance vs. element distinction.

    FWIW, while a lot of what is being said around and about GPT-3 IS ill-conceived hype, I do think it an interesting achievement, worth serious study.

  11. Rodger C said,

    July 28, 2020 @ 8:15 am

    In what sense is sodium chloride a molecule?

  12. Victor Mair said,

    July 28, 2020 @ 10:06 am

    @Bill Benzon

    Thank you very much for introducing us to GPT-3. I would be very happy if someone knowledgeable on the subject would write a guest post about it.

  13. Conal said,

    July 28, 2020 @ 10:54 am

    I was very glad to see NaCl (table salt) mentioned in one of the comments. For many readers, NaCl is already a familiar example. To make his ontological point, it happens that Mendeleev chose HgO, probably as a nod to Lavoisier. But almost any compound may be cited to make the same point, which goes like this: Chlorine is a greenish poisonous gas. Somehow that gas can become a 'harmless' constituent of table salt; and the salt in turn can be broken up (by extreme heat) into separate quantities of sodium and chlorine again. What is it that exists 'before, DURING and after' the salt? We can't say 'sodium and chlorine'; but we can write 'Na' and 'Cl'. And the latter is just as much a philosophical statement about what is eternal in the cosmos as it is a chemical statement. Hence, 'ontology' in the title of my article, because that's what Mendeleev, likewise, was trying to teach us, 150 years ago. (He is famous for his Periodic Table; here we are introduced to an entirely different part of his writings, largely unknown to the public, or even to chemists, for that matter.)

  14. Antonio L. Banderas said,

    July 28, 2020 @ 11:38 am

    What do you mean that NaCl is a molecule?

  15. Bill Benzon said,

    July 28, 2020 @ 12:08 pm

    NaCl is a chemical compound whose existence takes the form of molecules each containing an atom of sodium and an atom of chlorine.

    * * * * * *

    Ontology, yes!

    And an ontological confusion is at the heart of much of the discussion of GPT-3 (GPT=Generative Pre-trained Transformer). As I explain in a recent blog post (1. No meaning, no how: GPT-3 as Rubicon and Waterloo, a personal view):

    There are no “words” as such in the database on which GPT-3’s language model is based. Words have spelling, pronunciation, meaning, often various meanings, grammatical usage, and connotations and implications. All that exists in the database are spellings, bare naked signifiers. No signifieds, that is to say, semantics and more generally concepts and even percepts. And certainly no referents, things and situations in the world to which words refer. The database is all utterly empty signification, and yet it exhibits structure and the order in GPT-3’s language model derives from that order.

    In the common sense ontology words are relatively simple things having a variety of attributes: spelling, pronunciation, graphic form, gestural form, meaning, and grammatical usage. Linguists, of course, are very much interested in those things, and see words, not as simple things, but as compound objects embodying the intersection of various strata, to use a term favored by Hjelmslev, of language systems.

    When Victor, for example, posts about various topolects of Chinese, I see only "bare naked" signifiers as I don't understand any of those topolects. I don't see those characters as (constituents of) words. I merely see the characters, the signifiers.

    GPT-3, and a host of other models in natural language processing, works only with strings of signfiers (the database consisted of 300 billion tokens) and produces only signfiers. We look at the output strings and (almost) inevitably take them for full-blown words. That's what they look like, no? And these strings often make sense. So they've got to be words. They aren't, and when we see meaning, we're reading something into them that isn't there.

    The trick is to understand how such systems can exploit the structure existing among tokens in massive databases to produce such convincing simulacra of language. No one knows. Those models are black boxes. What they do isn't at all clear and it isn't easy to open the hood, as it were, to examine the engine.

  16. Philip Taylor said,

    July 28, 2020 @ 12:41 pm

    Bill, may I take issue with one part of your statement above ? You wrote "To common sense, human beings are ontologically distinct from animals; we have language and reason, animals do not". I take issue on at least three grounds : (1) human beings areanimals, so one cannot meaningfully compare and contrast them; (2) some non-human animals clearly have language, the cetaceans being the most obvious example; (3) some non-human animals can reason, something that was brought home with a vengeance recently when I relocated the bird feeders from the bird feeding station to a convenient washing line to prevent the rats from gaining access to them. Within 48 hours, several rats had worked out that if they climbed the nearby shrubs and climbed to the extremeties of the branches nearest the washing line, the branch would sag and allow the rat to gain access once again to the feeders. These rats had never had occasion to climb the shrubs before, and I for one believe that they reasoned how to re-gain access to the bird feeders rather than achieving their goal by pure good fortune..

  17. Bill Benzon said,

    July 28, 2020 @ 1:03 pm

    Philip, I said "To common sense…" But then went on to say, "To the biologist there is no such distinction" (between humans and animals). You're speaking more in the ontology of a biologist than in the common sense ontology. If there were no distinction between humans and animals in the common sense ontology, then killing animals would be murder, and be treated as such by the criminal justice system, and our whole industrial apparatus of meat production wouldn't exist. Nor would we treat cats and dogs as pets much less use animals as beasts of burden, at least not without compensating them for their labor at a fair rate. Etc.

  18. Bill Benzon said,

    July 28, 2020 @ 1:47 pm

    For those interested in following the debate on what's up with these Natural Language Processing systems, I recommend a recent blog post suggested to me by John Lawler: To Dissect an Octopus: Making Sense of the Form/Meaning Debate, by Julian Michael. It takes as its point of departure a recent paper by Emily M. Bender and Alexander Koller, Climbing Towards NLU: On Meaning, Form, and Understanding in the Age of Data (ACL 2020).

  19. David L said,

    July 28, 2020 @ 1:47 pm

    Chlorine is a greenish poisonous gas. Somehow that gas can become a 'harmless' constituent of table salt; and the salt in turn can be broken up (by extreme heat) into separate quantities of sodium and chlorine again. What is it that exists 'before, DURING and after' the salt? We can't say 'sodium and chlorine'; but we can write 'Na' and 'Cl'. And the latter is just as much a philosophical statement about what is eternal in the cosmos as it is a chemical statement.

    I suppose I am one of those horses that balks at being led to water and refuses absolutely to drink, but for the life of me I cannot see what philosophical point is at issue here. Of course, in Mendeleev's time, the underlying nature of elements and the way they could join together was almost wholly unknown, but now these things are known and understood. Chlorine and sodium can be combined to form salt and they can be uncombined again to revert to chlorine and sodium. Chlorine is a poisonous gas. Sodium is a highly reactive metal. Put them together and you get salt, an essential nutrient. What is the puzzle here? What is the philosophical conundrum?

    (As a couple of commenters have suggested, NaCl is not a molecule. See the 5th paragraph here, for example).

  20. Philip Taylor said,

    July 28, 2020 @ 2:13 pm

    Two replies in one. Bill, I am not a biologist; my views on the differences between humans and non-human animals I hold only through common sense, not as a result of any scientific training. David, the "puzzle" is "where did the poisonous gas go ? where did the metal go ?". I confess I don't see a great deal of merit in the debate, but I nonetheless believe that I understand on what it is based.

    But the question I would ask is "Does NaCl actually contain Na or Cl, or does it in fact contain only the protons, neutrons and electrons from which the Na and Cl were once composed ?" In other words, when two (or more) elements form a compound, does that compound contain the elements from which it was composed, or does it instead contain only their sub-atomic particles ?

  21. Bill Benzon said,

    July 28, 2020 @ 2:25 pm

    Philip: I'm not a biologist either. But I studied biology in high school.

    But am I to conclude that you regard killing animals as equivalent to killing human beings and that you do not eat meat, red, white, or fish?

    As for NaCl not being a molecule (David L.), Whoops! My bad. The situation is even more complicated than I'd thought. But my basic point obtains, "table salt" is conceptually different from "sodium chloride" and that difference matters. The concept of sodium chloride did not exist prior to the 19th century. But table salt, how far back do you want to go? I mean, do you want to stop at the point where people began eating on tables or do you want to go way back to when people recognized saltiness in their food?

  22. Rodger C said,

    July 28, 2020 @ 4:15 pm

    @Bill: I'm not sure if Philip is a vegetarian (I suspect he is), but you write as if you'd never encountered the concept.

    And I'm with David L: As someone with an undergraduate minor in chemistry, I can't make out what you're saying that has to do with anything but the history of knowledge, as opposed to some ontological distinction.

  23. Bill Benzon said,

    July 28, 2020 @ 4:28 pm

    Oh, I'm not talking about ontology in the sense of how the world really works. That's something of a mystery.

    I'm talking about our conceptualization. There are plenty of people who know little or nothing about NaCl but are quite familiar with table salt. And there are plenty of people who are quite happy treating animals as being categorically different from human beings regardless of what biology tells us. How many vegans/vegetarians argue that laws should be changed so that animal slaughter should be treated the same as murder?

  24. Andrew Usher said,

    July 28, 2020 @ 7:25 pm

    The distinction is, as I see it, sufficiently clear that it's doubtful Mendeleev was the first to think of it, even if he was first to express it in writing. Chemists been to be able to say that a compound like NaCl 'contains' certain elements, though it clearly does not contain those substances that correspond to the elements. It is incorrect to say that sodium metal and chlorine gas are somehow more real as substances, than is salt, simply because they can be identified with elements i.e. consist of but one type of atoms ignoring impurities. A single atom of gold is as much the element as is an ounce, but can't be made the substance we call gold.

    No concepts, though, are found in nature as such; they are all creations of man. When biology tells us correctly that humans are animals, it does not mean that the categories 'human' and 'animal' are more than groupings that we use because they are useful. And the idea that that means it's wrong to separate humans from other animals is political or ideological, not scientific; any species or group of species can be discussed separately, if it's useful to do so. And in the case of human beings, no one impartial can help agreeing that it's very useful indeed.

    Saying that 'humans have language and reason; [other] animals do not' is an essential truth despite the details. Yes, non-human animals can communicate, and apparently think, but it is a provable fact that they do not have language or reason as we do; they can not extend their communication or thinking to arbitrary complexity as we can (and linguists consider an essential distinction of true language).

    k_over_hbarc at yahoo.com

  25. Adrian Bailey said,

    July 28, 2020 @ 11:42 pm

    Is this use of the royal we still commonplace in academic writing?

  26. Michael Vnuk said,

    July 29, 2020 @ 4:10 am

    Bill Benzon quoted himself: 'Finally, consider the Morning Star and the Evening Star. Only by moving from the domain of common sense to the domain of astronomy can we assert that these stars are not stars at all, but simply different manifestations of the planet Venus.'

    'Star' has a different meaning in both domains. What's the big deal? And stars of stage and screen are something else.

  27. Victor Mair said,

    July 29, 2020 @ 4:55 am

    @Adrian Bailey

    Don't make your readers go through the whole o.p. and all the comments to find what you're talking about.

    I found it, but had to spend some time rereading. It would have been so easy for you to specify in an efficient phrase.

  28. Philip Taylor said,

    July 29, 2020 @ 6:13 am

    Bill, what I wrote was "(1) human beings are animals, so one cannot meaningfully compare and contrast them; (2) some non-human animals clearly have language, the cetaceans being the most obvious example; (3) some non-human animals can reason [e.g., rats]". How, from those three statements, can you find any evidence (or even suggestion) that "[I] regard killing animals as equivalent to killing human beings and that [I] do not eat meat, red, white, or fish" ? The two concepts are as different as chalk and cheese.

    Statement (1) sets out the basic premise — all humans are animals, but not all animals are human; statements (2) and (3) demonstrate that not all non-human animals lack the very traits that you would ascribe only to humans (language, the power to reason). Because "animals" is a superset of "humans", it is not meaningful to ask without further qualification whether killing animals is equivalent to killing humans. If (as I very much suspect) you are using "animals" as a shorthand for "non-human animals", then I do not regard "killing non-human animals" as equivalent to "killing human animals" but to my mind they differ only on relative terms. Both can be wrong when conducted by sentient beings such as ourselves, but cannot be wrong when conducted by natural predators such tigers. Tigers do not have the concept of "right" and "wrong" (at least, as far as we know today), so when they kill that killing is neutral, no matter whether it be of a human or of a more common prey species. When we kill (we who should be able to perceive the difference between right and wrong), then we need to factor in our motivation for so doing. If we kill for sport, then clearly that is unquestionably wrong. When we kill out of vengeance, it is more understandable but still wrong; the same when we kill in the interests of scientific research. But when we kill for food, then we are in the same position as the tiger — we are killing in order to survive [1]. And that is not "wrong", because that is how the entire animal kingdom (of which we are just one small part) operates — not all animals kill other animals in order to live, but all kill something (where that "something" may be (e.g.,) grass, in the case of cattle, but even then the odd insect or two will sometimes be inadvertently killed and ingested in the process). Killing can only be wrong when the killer is sentient and when he or she kills for reasons other than to survive.

    As it happens, I am, for better or worse, a meatoholic, even 'though I would prefer not to be, but I nonetheless value all life, which is why I am currently trying to live-trap my rat infestation and relocate them rather than doing as most would and seeking to kill them. If I cannot succeed in live-trapping and relocating them, then I may have no recourse but to killing, but I would infinitely prefer not to have to follow this route.

    Apologies for the long response, but I felt that the points I am seeking to make above are worth making.
    [1] Some would argue that the same is true in the case of killing for scientific research, where that research is intended solely to benefit other animals (including humans). I can see some merit in both sides of that debate.

  29. Conal said,

    July 29, 2020 @ 7:49 am

    The horse-to-water metaphor itself clicked with David L., but after that he confessed that"for the life of me I cannot see what philosophical point is at issue here." In this longish comment, I will try 'sneaking up' on the ontology facet of Mendeleev's work, to see if I can show it in a different light. (But first: In several of the comments I see the notion of "Mendeleev-back-THEN who didn't know much vs. we-who-know-so-much-TODAY." That's almost comically wrongheaded. Mendeleev knew a hell of a lot. And the issue isn't 'then and now'; the issue with his philosophy is that even today many people still have not caught up with him, in large part due to slovenly translations out of Russian circa 1900 which are still referenced by Anglophone writers since no one has yet provided a competent translation of his admittedly voluminous works. That's what my article tries to remedy, in part, by focusing on the original Russian of one of the passages in his writing that is 'famous' in Philosophy-of-Chemistry circles.)

    Who 'owns' the Periodic Table? Let's begin with a quick history review. In the 1860s, the Periodic Table (hereafter 'PT') appeared in France, Germany and Russia thanks to the following three individuals: Alexandre-Émile Béguyer de Chancourtois (1862); Julius Lothar Meyer (1864); and Dimtri Mendeleev (1869). Personally, I'm all for Chancourtois, but in the history books, Mendeleev gets the credit. Why? [A] Because he excelled at noisy self-promotion (and he had the right look: a 'Karl Marx' beard, the kind in which many generations of mice might have lived, for all we know); [B] because he was prolific — see, for example, the repository at http://www.chem.msu.ru/rus/mendeleevia/txt/; and [C] he was able to look beyond chemistry and articulate the philosophical (ontological) facet of his table of elements.
    Now in all three cases, it was the person's knowledge of chemistry that led to his formulation of a PT; moreover, the Periodic Table of Elements is proudly taped to the wall in every chemistry classroom, whereas it will probably not be seen on the wall of a physics or philosophy classroom. Accordingly, the naive student may be forgiven for assuming that, "Of course, it is the Chemistry Department that 'owns' the Periodic Table." But if we step back and look at the broader landscape, it is in the areas of Philosophy and Astrophysics (and sometimes nuclear physics) that we find a more persuasive 'owner' of the PT. Why? Because in those fields, the outlook is cosmic. For those fields, the PT is an assertion about the eternal building blocks of the universe itself; in sharp contrast to that ontological take on the elements, a chemist's typical view of the PT goes like this: "Hm, potassium (K) is in the same column as sodium (Na); I wonder if potassium chloride (KCl) might work as a salt-substitute?" (Yes, KCl is widely sold as a substitute for NaCl, for people who wish to limit their sodium intake.) That's a very clever and fun way to look at the PT, but it is by and large provincial. Earth-bound. Biped-simian-centric. Now for that terrible word 'ontology':

    I think part of the horse-led-to-water problem might turn on the hideous lexicon of the professional philosopher. Once we've disposed of the UK atrocity 'maths', surely there are few uglier words in English than this pair, which might seem to have something to do with a fatal disease: 'epistemology and ontology'. And that is a kind of tragedy, since it is important to be able to talk conveniently about 'the part of philosophy that is the study of how we know things' (epistemology) and 'the part of philosophy that is the study of what and how a particular thing exists or fails to exist' (ontology). Perhaps our metaphorical horse arrives at the River Ontology and thinks, "That doesn't even look like water. I don't trust it; it smacks of ivory-tower parlor-games. I'll pass." If the ugliness of the word 'ontology' is the main problem, it might help a bit to mentally substitute the German equivalents, which are: Erkenntnistheorie and Ontologie /ɔŋkoloˈɡiː/. Or, since LL begins and ends with Victor's focus on Chinese, let's consider the corresponding terms in that language: rènshílùn 認識論 and běntǐlùn 本體論, which are even easier on the ear than the German words, and likewise avoid  the off-putting recondite look 'epistemology' and 'ontology'. hth

  30. Bill Benzon said,

    July 29, 2020 @ 8:19 am

    Philip: As I'm sure you know, Darwinian evolution has been and continues to be resisted because it asserts a continuity between humans and animals. People who so resist evolution do not think of animals as a superset of humans and animals alike. That is a distinctly different conception of the world from one in which humans are descended from apes and so a member of the set of animals along with gerbils, crows, octopi, spiders, millipedes and so forth.

    That (kind of) difference is what I am interested in. I am further asserting, perhaps incorrectly, that the common sense view of the world is much closer to the pre-Darwinian conception. When one operates within a modern biological conceptual framework, whether one does so informally as a non-biologist or more formally as a biologist, that common sense view does not exist. The legal status of animals, however, is not grounded in the biological conceptual framework. It is based on an earlier conception in which humans are higher kinds of creature.

    That earlier framework is sometimes known as the Great Chain of Being and can be traced back to the Greeks. As it developed it came to include several orders of angelic beings: archangels, seraphim, and cherubim. They are not, so far as I know, recognized by our legal system. The system does, however, recognize oaths sworn in the name of God, who is at the very top of the chain.

  31. David L said,

    July 29, 2020 @ 9:38 am

    @Conal Boyce: My only response, alas, is that I still have absolutely no idea what you are talking about.

  32. Philip Taylor said,

    July 29, 2020 @ 11:19 am

    Bill, let me be frank — as far as I am concerned people who reject the concept of Darwinian evolution quite possibly also subscribe to the flat-earth theory and deny both the existence of climate change and of our (human) responsibility for it. I have no idea whether you fall into any of those camps, but just in case you do, let me clarify that this is my assessment of a group of people, not of any one individual.

  33. Bill Benzon said,

    July 29, 2020 @ 11:41 am

    Philip: I don't fall into any of those categories.

    And I'll be equally frank: You don't seem to have any idea what I'm talking about.

  34. Philip Taylor said,

    July 29, 2020 @ 11:55 am

    Then I can only apologise for wasting both your time and that of the other readers of this forum.

  35. Victor Mair said,

    July 29, 2020 @ 12:01 pm

    Can some compassionate soul come up with a bit of upāya ("expedient means") to help David L. get a handle on the ontological facets of Mendeleev's work?

  36. Bill Benzon said,

    July 29, 2020 @ 2:49 pm

    Philip: I will say this: I'm sorry that we got sideways with one another. However it is useful to me to know that what is obvious to me, from having studied it for (at this point) decades, is not at all obvious to others, others who are intelligent, knowledgeable, and sophisticated, but haven't been, well, whatever.

  37. Philip Taylor said,

    July 29, 2020 @ 2:53 pm

    I couldn't impose on you to explain what "whatever" is, I suppose, Bill ?

  38. Bill Benzon said,

    July 29, 2020 @ 3:57 pm

    Been immersed in a certain approach to conceptual structure? Not much help is it.

    Way up thread I mentioned an article I had published. The final draft is available online: Ontology of common sense. This working paper is in the same vein: Ontology in Knowledge Representation for CIM

  39. Philip Taylor said,

    July 29, 2020 @ 5:33 pm

    OK, thank you Bill — two quick comments before I go to bed. 1) Keil found a common sense ontology in which sentient beings (primarily humans) and non-sentient beings (non-human animals) are types of animal, animal and plant are types of living thing. So there Keil and I agree, while it would seem that you disagree. 2) "If we consider how they are constructed, then computers are clearly functional artifacts. If we consider how we interact with them, then they have kinship with sentient beings, for we interact with them through language". I am not convinced that how we interact with something is necessarily significant. I interact with bread dough by punching it, and I interact with my opponent in the boxing ring by punching him, but I would not use those facts in order to seek to draw any parallel between bread dough and a boxer. My common sense tells me that computers are not sentient, and I have considerable doubts as to whether they ever will be. If they ever were to become sentient, then it would only remain for them to be able to reproduce in order for mankind to be able to claim that he had created life.

  40. Jake said,

    July 29, 2020 @ 6:16 pm

    Phil asks: "Does NaCl actually contain Na or Cl, or does it in fact contain only the protons, neutrons and electrons from which the Na and Cl were once composed ?"

    Evidence is that it is the former : http://physicsopenlab.org/2018/01/22/sodium-chloride-nacl-crystal/

    Also @Bill you quoted yourself as saying "For the scientist, the glass of the window pane is a liquid". This is an urban legend, glass is a (kind of) solid.

  41. Philip Taylor said,

    July 30, 2020 @ 2:45 am

    Thank you Jake. As you clearly have expertise in these matters, may I ask a related question ? Referring back to the mercury/cinnabar discussion, is it known (a) whether a single atom of mercury exhibits the reflectivity/sheen of liquid mercury, and (a) if it is known, and (b) it does not, is it known how many atoms of mercury need to be co-located before (a) they exhibit the reflectivity/sheen of liquid mercury, and (b) before they also exhibit the liquid characteristic ? Clearly the actual numbers do not matter from an ontological perspective, but I am nonetheless intrigued by the question.

  42. Bill Benzon said,

    July 30, 2020 @ 6:15 am

    Hmmm… Unless you consulted Keil directly, Philip, you are using what I say in my article to argue against me. Fair enough I suppose. However…. It's been a long time since I read Keil (I published that article almost 30 years ago) and I don't have the book immediately available, so I can't see what kind of questions he asked of the children. But I am suspicious that he had to characterize their categories with terms they would never use, such as sentient beings vs. nonsentient beings.

    What's at issue is a moderately technical matter in semantics of how properties are inherited in a set of closely related terms. But this is not the place to try to hash that out. For one thing, diagrams would be very helpful, in fact, necessary. And I can't see how to slip them in. But if you are at all interested, take a look at that other paper, Ontology in Knowledge Representation for CIM. I discuss the matter starting on page 3, Ontology and Assignment.

    As for the significance of how we interact with things, how often do you converse with the moon and the starts, with rocks, and blades of grass? When you do so, do they talk back?

  43. Rodger C said,

    July 30, 2020 @ 8:26 am

    @Philip: A single atom of a metal can't have metallic sheen, because it's a property of the shared electrons in a mass of the metal.

  44. Rodger C said,

    July 30, 2020 @ 8:30 am

    And of course liquidity is of course also a property of a relation among atoms. As for exactly how many are needed to exhibit either quality, I suspect one would have to consult the angels dancing on them.

  45. Bill Benzon said,

    July 30, 2020 @ 9:36 am

    …the angels dancing on them.

    I suspect those angels are fairly high on the Great Chain of Being, certainly higher than we are. I am not, however, informed on the capacities and duties allotted to archangels, seraphim, cherubim and so forth so I don't know of what sort those dancers might be.

  46. Daniel said,

    July 30, 2020 @ 12:02 pm

    I'm late to comment, but I somewhat disagree with Conal's interpretation of Mendeleev's paragraph. The linked paper elides phrases that are deemed to be extraneous, and I don't think they are, or he would not have written them.

    I do agree with the overall thrust that there is an important ontological distinction that Mendeleev introduces using the term "element", but I don't think "substance" is the word he uses to contrast with "element". Rather, "substance" in all cases refers to the idea of underlying reality (note the sub- prefix). This sounds a lot like christological language: "of one substance with the Father".

    It appears to me that Mendeleev is acknowledging that the term "simple body" is being used like our modern word 'element', with two distinct ontological uses: (1) as a "homogeneous substance", that is, a material composed of one kind of atom, (2) as part of a "complex substance". In the second use, he actually says "the substantial part", which may refer to the fact that this combination is not visible, that there's something substantial about it. I think that this is an apt way to imply chemical bonding.

    Mendeleev then proposes to use the word "element" to describe the second use of "simple body" and restrict "simple body" to the first use. We can see this because he later writes that mercury oxide does not contain two "simple bodies" but two "elements".

    We can see that "substance" is then used later to mean underlying reality in the use of the phrase "substance of". He writes that mercury oxide contains the "substance of these simple bodies". (I will say I don't understand why he doesn't say that it contains the substances [plural] of these simple bodies".)

    I think "substance of" can refer to different levels of depth. Mendeleev uses three examples: (1) Mercury oxide contains the substance of mercury and oxygen. (2) Water contains the substance of ice. (3) Bread contains the substance of grain. In each case, the underlying reality is at a different level. In example 1, the underlying reality contains Hg and O atoms, as these are rearranged chemically to form mercury oxide. In example 2, the underlying reality contains water molecules, as the distinction between water and ice is one of arrangement of molecules. In example 3, the underlying reality contains the polymers of starch and protein, which are rearranged (forming gluten) and even chemically modified (browning) on the way to becoming bread.

    In short, I think the passage can be interpreted so that all parts make sense.

    I will say that it has always bothered me that 'element' in chemistry is used in both senses. I would use 'element' in the way that Mendeleev defines it. The modern use of 'element' to mean a chemical composed of just one type of atom is irritating. I would say that it is an 'elemental'
    material or chemical.

    In closing, I will say that the book, _Elements: A Visual Exploration of Every Known Atom in the Universe_ by Theodore Gray, gets this right. Although it most prominently displays the elemental form, it also shows common compound materials, both natural and synthetic, where the element is notably present.


  47. Philip Taylor said,

    July 30, 2020 @ 12:21 pm

    Your informed comment would encourage me to trust your recommendation of Elements: A Visual Exploration of Every Known Atom, Daniel, but I am afraid that I find the Amazon blurb a complete and utter turn-off :

    The Periodic Table is huge and intricate and seen to be a thing for only Scientists to worry about. This book allows all to have access to what the symbols and two-letter Scrabble words that everyone thinks must be cheating actually mean and also where we can encounter them in everyday life. From Batteries to Toothpaste, Einsteinium to toy cars, it's truly awe-inspiring to find out how many of these elements we really know in other forms. Gray allows us to see materials in their stunning raw form and then tells us their history, discovery and where they are used. This is the coffee table book of the Science world but also an amazing collection by a man that is passionate about how the materials featured make up the world around us and wanting to make this accessible to a wider audience.

  48. Philip Taylor said,

    July 30, 2020 @ 12:26 pm

    Thank you, Roger, but I should clarify that I wasn't asking exactly how many angels can dance on the head of a pin, more "to the nearest power of ten", how many atoms of Hg are necessary before sheen and liquidity are observable (at a microscopic level, of course).

  49. David L said,

    July 30, 2020 @ 1:50 pm

    Daniel, thank you for that very clear account.

    I somewhat agree with your penultimate paragraph, and I can think of cases where it would be worthwhile (for clarity rather than pedantry) to insist upon the distinction. In practice, though, as ycx said right at the top, the context almost always makes plain what meaning is intended.

  50. D.O. said,

    July 30, 2020 @ 2:45 pm

    Philip Taylor, someone should actually know the answer, but we can make a rough estimate. A typical distance between atoms in a condensed state is a few Angstrom and a typical visible light wave length is about a few hundred nanometers. It makes it about 1000 atoms in a row to reflect visible light. You won't get away with creating a metallic state with a row of atoms, need at least 2 dimensions for that. As for the third dimension, I am not sure you really need any depth, so I guess about 10⁶ if you can make them into a monoatomic layer. You won't observe its sheen with a naked eye, obviously. The metallic state itself will form with much less. I will take a pass on viscosity.

    I think I can answer your question way upthread, In other words, when two (or more) elements form a compound, does that compound contain the elements from which it was composed, or does it instead contain only their sub-atomic particles ?. The chemical identity of an element is contained in its nucleus and is determined by the number of protons. The chemical compounds whether of molecular, ionic, or metallic type are formed by rearranging the electronic clouds. Which means that the identity of the elements are preserved, but the properties of the atoms are not. From where I sit, that means that "compound[s] contain the elements", but you may judge for yourself.

  51. Bill Benzon said,

    July 30, 2020 @ 3:42 pm

    @D.O. LOL! Isn't the world marvelous?

  52. Jake said,

    July 30, 2020 @ 3:47 pm

    @Philip : I agree with Roger, and also should mention that a single atom of any element is much smaller than visible light and doesn't really have a 'color' as such (emission lines aside).

    The liquid nature is a hard question with a lot of caveats, and is firmly in the realm of 'condensed matter physics'.

  53. Jake said,

    July 30, 2020 @ 3:49 pm

    Sorry for the useless post there, I had it typed up this morning and didn't actually hit 'send' until this afternoon, neglecting to re-load the page.

  54. Conal said,

    July 30, 2020 @ 4:09 pm

    Phil asked: "Does NaCl actually contain Na or Cl, or does it in fact contain only the protons, neutrons and electrons from which the Na and Cl were once composed ?" To which Jake responded with a link where we see a nice graphic of NaCl crystal structure. Fine. So far so good. But there are other ways to make the point that are less abstract. If one had the means to turn some salt molten, at around 800 degrees C, one could do an electrolysis experiment, the result of which would be actual sodium metal and chlorine gas, as in the set up shown here…
    … the point being, that we (thanks to Mendeleev's insight) do not really care what's inside the 'black box' of NaCl or any other compound. The salient point is that the constituents C-O-M-E B-A-C-K O-U-T, as 'themselves', unscathed, as it were.
    Granted, most people are afraid of playing with molten salt, but with HgO (i.e., with Mendeleev's 'red mercury') one can do the parallel experiment at considerably lower temperature — in a test tube heated to around 500 degrees. My favorite such experiment, one that can be carried out 'in the kitchen' at room temperature, is the dissolution of SnCl2 into tin and chlorine, as shown here:
    Let's return to Phil's train of thought about protons, neutrons and electrons: Suppose we peered inside some salt and saw only a chaotic scrambling of free quarks (UP and DOWN quarks that had somehow escaped from their protons and neutrons, which is currently thought to be impossible), swimming about freely in some incomprehensibly loony Dance of the Quarks, i.e., at a structural level even lower than that of protons and neutrons. Even then, Mendeleev's way of dealing with the 'black box' still holds, 150 years later, because, again, WHATEVER it is that goes on inside the NaCl, both the Na and the Cl can be made to "come back out as themselves." THAT'S what this is all about, both 'chemically' and philosophically, i.e., ontologically. (Sure, as alluded to by Daniel, there are complexities, and even some outright absurdities in Mendeleev's Russian that must be navigated, so my use of the word 'substance' (in this fairly informal context) was indeed a deliberate over-simplification. Please don't guess about Mendeleev's Russian, though; rather, respect the fact that my article must be read in 'math' style, as each page builds logically on the preceding page[s], as I retrace the sad and stupid story through the original sources, in Russian, German, French and English.)
    Another angle on NaCl: Here is a demonstration of NaCl formation, de novo, from sodium and chlorine:
    From there, we can try using our imaginations to picture the violence and nonintuitive nature of the corresponding experiment, via electrolysis at 800 degrees C, by which the sodium and chlorine would "come back out again as themselves," thus declaring 'Na' and 'Cl' to be building blocks of the cosmos, not just of our sprinkled salt.

  55. Andrew Usher said,

    July 30, 2020 @ 9:45 pm

    I first mentioned what several others have raised above: a single atom of an element does not have the properties of the solid or liquid 'element'. This is, as I went on to say, a major argument for the distinction: your one atom of mercury can't be mercury substance, but must be mercury element, by definition.

    Whether a compound really contains the elements in its chemical formula or just their subatomic particles is essentially a semantic and not factual question. Here, again, we prefer the most useful answer: the elements are 'contained' in the compound, because they can be extracted out of it by chemical processes, and other reasons.

    That experiment with SnCl2 is actually electroplating, though with surprising results!

  56. Leo said,

    July 31, 2020 @ 1:48 am

    Philip Ball discussed this problem in Chemistry World recently.


    With my apologies to Conal Boyce, Ball's thoughtful article credits Paneth with the substance/element distinction.

    As the article points out, "our whole notion of the periodic table mixes the two [definitions] awkwardly". The entries in the table are ordered sequentially by their atomic number – invoking the "element" concept that defines, say, carbon as any atom containing six neutrons – yet the two-dimensional structure of the table reflects the bulk properties of substances, grouping together alkali metals, noble gases, etc.

  57. Leo said,

    July 31, 2020 @ 1:50 am

    Obviously I meant "protons" in the above comment! What a gaffe.

  58. Philip Taylor said,

    July 31, 2020 @ 2:18 am

    My very sincere thanks to you all. I have just one reservation remaining. Just because « the original two elements 'come back out' » does not, of itself, convince me that 'they were there all along', because I could disassemble anything into its component parts and then re-construct it, but the fact that no different elements ever 'come back out' does, to my mind at least, appear to clinch the case.

  59. Andrew Usher said,

    July 31, 2020 @ 6:54 am

    It is not true, either, that the periodic table mixes the two notions. Yes, the periodic table does organise the properties of the elements as substances – but that's just a by-product of organising _all_ their chemical properties. In fact, historically, elements could be slotted in to the periodic table without having ever isolated the free elementary substance.

    Though it is not required for understanding of the periodic table, this is of course a consequence of the physical principles of electron configurations.

  60. Conal said,

    July 31, 2020 @ 7:46 am

    Andrew Usher asserts, "That experiment with SnCl2 is actually electroplating." Not so. Sometimes we see the word 'electrolysis' and think immediately of a copper-plating or silver-plating hobby in the garage, but this kind of electrolysis is fundamentally different. First, I probably should have mentioned that the solution that we see in the petri dish is stannous chloride. (Here is a nice short video that shows how stannous chloride is prepared, from tin and hydrochloric acid:
    https://www.youtube.com/watch?v=ybXIlEU3s5M .)
    Now back to the other video where we see tin crystals growing, by time lapse photography. The metal we see is pure tin (Sn); there is nothing to be 'plated' (unless we wish to say whimsically that the tin is 'plating itself'). As the tin crystals develop near one wire, chlorine gas is 'evolved' near the other wire. The point is that whatever atoms of tin and chlorine went into the stannous chloride (SnCl2), it is tin and chlorine atoms that come back out eventually, if the compound is dissociated. Nor is time a factor in these formation/dissociation processes (as Schopenhauer, of all people, was keenly aware, by the way). Returning now to Mendeleev's example, whatever mercury and oxygen atoms go into a 'red mercury' compound (HgO powder), even after 50 billion years, the mercury will 'remember' what it is and come back out again as mercury atoms — even if, inside the compound, it had taken on the form of 17 octillian nano-sized piglets quietly squealing for the duration. In other words, in the 'black box' approach used by both Lavoisier in 1779 (discovery of oxygen) and by Mendeleev circa 1869 (elemental ontology lesson), one really doesn't care what is inside the 'black box'; all one cares to explore is what goes INTO the notional box and what comes OUT of it: namely, elements, all of which 'remember' who they are.

  61. Bill Benzon said,

    July 31, 2020 @ 10:58 am

    …form of 17 octillian nano-sized piglets quietly squealing for the duration.

    I wonder what GPT-3 could make of that.

  62. Andrew Usher said,

    August 1, 2020 @ 7:22 am

    I didn't mean 'electroplating' literally, as in the result, but that the process was that of electroplating – running a current through a metal solution to get the metal to deposit on the cathode. That would be a more appropriate word to describe the process, anyway, than 'dissolution' or 'dissocation'.

    By the way, no chlorine is being evolved at the anode, and the video doesn't claim it. Presumably the tin is instead oxidised (as you'd expect from the potentials) and 'SnCl4' is being produced instead.

    But you main point is right, and is of course what led to the definition of elements in the first place. Elements are the conserved quantity in all chemistry.

  63. David Marjanović said,

    August 1, 2020 @ 12:21 pm

    Disclaimer: I have only skimmed the longer comments.

    Is this use of the royal we still commonplace in academic writing?

    Depends on the language and the discipline. In French it seems universal (but a single female author will write things like nous sommes étonnée, with "we are" in the plural but "astonished" in the feminine singular). In English in the natural sciences it has pretty much died out, but still seems to occur elsewhere.

    And of course liquidity is of course also a property of a relation among atoms. As for exactly how many are needed to exhibit either quality, I suspect one would have to consult the angels dancing on them.

    Research in "clusters" has been going on for some 30 years now. The answer for liquidity seems to be a pretty low number of atoms, like a dozen or less, but there is definitely no sharp cutoff for a metal.

    As the article points out, "our whole notion of the periodic table mixes the two [definitions] awkwardly". The entries in the table are ordered sequentially by their atomic number – invoking the "element" concept that defines, say, carbon as any atom containing six neutrons – yet the two-dimensional structure of the table reflects the bulk properties of substances, grouping together alkali metals, noble gases, etc.

    What it really does is reflect the arrangement of the electron orbitals, which depends directly on the number of protons. The bulk properties depend directly on the arrangement of the electron orbitals.

  64. Leo said,

    August 1, 2020 @ 2:42 pm

    @David Marjanović and Andrew Usher:

    I take your point that the structure of the periodic table reflects the electron configuration of the elements, as seen from an "element" perspective, as well as their bulk properties as seen from the "substance" perspective. Clearly, the periodicity in the former, which is more fundamental, causes the emergent (and historically earlier recognised) periodicity in the latter – at least for most of the table. But I think the point being made by Philip Ball and his interviewee is that the chemistry community is not sure what to do when the correspondence between electron structure and bulk properties starts to break down. Take the lanthanides and actinides. Some versions of "the" (!) periodic table place lanthanum and actinium in the f-block (https://periodic.lanl.gov/index.shtml), others in the d-block (https://www.rsc.org/periodic-table). So there is more than one periodic table.

    My educated but non-expert understanding is this: once you get to the f-electrons, relativistic effects become non-negligible, and the bulk properties of elements no longer depend on their atomic number in the same predictable way as for lighter elements. However, if chemists were unanimous about whether to order the periodic table in terms of electron configuration or bulk properties, there would not be any uncertainty over its structure. In fact they continue to dispute it, which suggests they have not settled the matter of whether the periodic table should purely reflect the underlying physics or leave some room for chemical phenomena.

  65. Leo said,

    August 1, 2020 @ 3:01 pm

    (My above comment is a response to David Marjanović and Andrew Usher)

  66. Philip Taylor said,

    August 2, 2020 @ 4:53 am

    Conal — your "squealing nano-pigs" analogy very much resonates with my own feelings as expressed above, with one difference : I would express it as "… all of which 'remember' who they were", thereby allowing for the possibility that, once bound into a molecule, the elements (qua elements) temporarily cease to exist.

  67. David Marjanović said,

    August 2, 2020 @ 7:45 am

    So there is more than one periodic table.

    Yes and no: there are different 2D representations of it. Ideally there should be loops coming off the page.

    I've seen very wide tables where the lanthanides and actinides were simply integrated in the table instead of added under it as footnotes.

    Relativistic effects are important elsewhere: they're responsible for some of the odder features of gold and mercury, for instance.

  68. Andrew Usher said,

    August 2, 2020 @ 9:08 am

    You basically have it, but the periodicity that was noticed first was periodicity in chemical properties generally, not in properties of the elemental substance alone – based on the latter, it would have been hard to see periodic patterns in most of the metals, or to see any pattern (besides not being typical metals) in oxygen, sulphur, selenium, tellurium – for those last, chemists had to actively ignore differences of the elemental substances, which made no sense before quantum theory. Finally many elements had not been isolated as a pure substance when the periodic table was constructed, and the heaviest elements recently added never will be – but that is no difficulty, as most of the chemical properties are, or can be defined, based on the behavior of the atoms separately.

    The place of lanthanum and actinium is not a right or wrong issue – both are defensible, as is not making a choice at all. The chemical properties of that group of elements are so similar that it's not possible to have a consensus that lanthanum or lutetium should be the one to go below yttrium in the table.

    David Marjanovic:
    I think, too, there can't be a sharp threshold for liquidity with the number of atoms accumulated (at least without fixing an arbitrary temperature, which I would not consider permissible).

  69. Conal said,

    August 3, 2020 @ 1:29 pm

    Picking up on Philip Taylor's elaboration on the 'squealing nano-pigs' analogy (in his August 2 post), it occurs to me that there is something in Data Communication Theory that might look — from a distance — to be analogous to the round-tripping of Na and Cl through NaCl, or of Hg and O through HgO, etc. But there is a subtle difference to note. Near the beginning of Claude Shannon's Mathematical Theory of Communication (1948) there is a block diagram in which he depicts the system in this symmetrical, easy-looking five-part scheme:

    Message Source, Transmitter, CHANNEL, Receiver, Message Destination.

    But soon we learn that the actual system contains these steps:
    Analog-to-DIGITAL translation of the Message, and encoding of the message into the Transmitter; DIGITAL-to-analog translation to create signals to be sent down the CHANNEL; analog-to-DIGITAL translation at the Receiver, to recapture the encoded Message; decoding of the Message, and DIGITAL-to-analog translation to make it audible at the Destination (i.e., in the telephone receiver or other device).
    It would not be reasonable to say that this communication system 'remembers' what the original Message was; rather, the system is a vast set of instructions crafted by Bell Lab engineers, and each instruction 'knows nothing' of those that precede and follow it. Now back to molecules and their constituent elements: In that context, there are no 'instructions given by engineers' (or by some analog to the engineers); rather, each atom remembers 'who it is' by virtue of its PROTON-COUNT ALONE. I realize it's a long way from 'proton-count' to my silly nano-pig image, but the point of that image was this: For philosophers, the focus is on the 'round-tripping' of elements through the molecule; on the fact that what goes IN comes OUT, rather miraculously (even after several billion years); not on the details of what transpires inside the molecule (or crystal lattice) in the interim, no matter how baffling or arcane those details may be.

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