2011 Paul D. Bartlett, Sr. Lecture - Who Discovered The Periodic Table?

[Applause] thank you very much for that very kind introduction it's a pleasure and an honor to be here thank you all for coming um let me see where I should start with this um so we have to dim the lights a little bit I think to see what's going on here but the title of the talk is who discovered the periodic table and I actually have no idea who discovered the periodic table and I'm going to tell you why and that's what's going to take up most of the rest of the time here uh when you open a chemical textbook today you will see a periodic table you'll probably see it before then when you walk into a chemistry classroom when you open up your textbook there'll be a historical sidebar there but you'll have a picture of someone who will be the discoverer of the periodic table that person will have a long Grizzly beard that person will almost always be Dimitri Ivanovich Mendeleev who is a chemist who worked in St Petersburg but if you have an especially ecumenical textbook or if you had a German textbook about a century ago they might also include a guy with a beard named Julius lotar Meyer if you have a really interesting historically sophisticated textbook it might also include a guy named Gustav hinrix or John Newlands all of these guys also have long beards um mendeleev's periodic table was in was discovered or invented depending on what term you want to use in 1869 or 1871 depending how you figure Myers was discovered in 1864 1870 1868 1871 again depending on how you figure and the reason why people make these assessments that X discovered the periodic table is because they kind of think of it like it's a rock like you found this rock and that's what it is the periodic table I've discovered at first but that's not what the periodic table is the periodic table is a complicated mixture of information and if you know what the periodic table is what its Essence is you look for the person who found it first and then you've got it the discoverer I don't know what that Essence is so I don't know who found it first but let me explain what I mean this obviously is the periodic table of elements I know that in many of you this instills bad memories from high school um it's really quite a lovely construction um so what this thing does is it has two basic axes running this direction sort of left to right are increasing atomic number from 1 to 100 and whatever depending where we are on this table this one's a little old we have some more um atomic number is the number of protons that are in the nucleus of an atom which determines how many electrons are outside the atom and therefore its chemical properties none of that's true in the 19th century no one knows about protons the electron is discovered in 1897. uh Mendeleev doesn't believe in the electron uh there's all sorts of reasons why the electron is not a good way of thinking about it so in the 19th century that's not how they order it they order it by atomic weight which is this number down here you can do that for most of the way and generally the atomic numbers increase as you move across and down there's a couple of sticking points tellurium is actually heavier than iodine and nickel and Cobalt are wrong but basically they all increase that particular way so why would you want to do this well when you array them in order of atomic number or generally increasing atomic weight you find that they you end up with vertical periodicities that is every so often the same properties recur and that's extremely interesting that all of these elements act similar and they act similar with a kind of regularity and therefore you can read a huge amount of information off of this table if you know something about manganese you know something about technetium which doesn't exist naturally in nature but you know what its properties would be like because it's below it it's an amazing condensation of information there's lots of things about this that weren't true in the 19th century these rare Earths are really tricky and they didn't really know many of these in the 1860s and this thing was discovered in the 1890s 1900s the noble gases they don't know about those either but the basic idea is to have these two axes where you do chemical properties which is related to the bonding power of an element or it's valency and you have atomic weight or atomic number on the other axis and that way you get the properties and the weights correlated two-dimensional Grid it's extremely sophisticated none of this stuff is true in the 19th century in terms of what it is so that's what it is today what was it or what is the essence of the periodic system so let me tell you before I get to that what I'm going to do today I'm going to talk about three different things first I'm going to provide an analysis using the periodic system as an example of how we should and should not think about priority disputes in the past the history of science is littered with people claiming they discovered the same thing first it's one of the many ways in which science is done two people come up with a discovery very close by whoever gets it first gets the credit it's a very important feature of science but there are some ways of thinking about this that are helpful in some ways that are not and I'm going to use this as an example second I'm going to talk about how the periodic system emerged for the case of Mendeleev and for Meyer and in particular the pedagogical context in which they came up with the system that is how they built it into their teaching and how teaching in fact generated those the tables that they used and I'm going to do that in order to point out that they're not talking about the same system they have things that look identical to us but they think they mean different things and the third thing I'm going to do is provide a brief history of why that periodic table priority dispute happened and why it got so nasty so fast and it did because of very local tensions between Germans and Russians in Saint Petersburg there's a very particular German Russian conflict going on that's very very local with a set of maybe 15 people involved that spirals into a big fight about who discovered this law of nature first so I'm going to do those particular three things hopefully that's not too many things so what is the periodic system of elements uh is it the abstract idea that there should be a system that organizes all knowledge that this abstract idea should exist is it recognition that there's a periodic law or some kind of regularity that undergirds it is it putting them in a two-dimensional some sort of tabular format two by two format if so which one there are about a hundred a little less than 100 topologically distinct versions of the periodic system that you can look at they're in two or three dimensions so which one of those this is by many this is the standard one but it's in many respects not adequate uh by depending on what you want to do with it it's not good for spectroscopy and other things like that um even if we just consider the issue of what the law is supposed to be we find that historians chemists and philosophers have a lot of disagreement about what the periodic table Essence is what the essence of the system is depending on which of these you pick you find the person who did it first and you find a Discoverer so possibility number one is recognition that what I said earlier that the periodic variation of properties that happens with Rising atomic weight uh or you could say that recognition plus putting it in a two-dimensional Grid or possibly a three-dimensional grid of some kind classifying all of the known elements not just some in the 1830s and 40s various people classified three elements and showed that there was a regularity with those we don't consider them discoverers of the periodic system so you have to do all the elements not just a few how about leaving gaps in the 1860s by the end of that decade 63 elements were discovered there are 92 naturally occurring elements they obviously didn't know about a lot of them so some people when they made their periodic systems left holes where they thought something should be but has not was not discovered yet they could use the periodic system to look at the pattern and try and correct some of the empirical values that you find like say oh that Atomic weight's wrong it should be this because the system requires that it be this that's called retrodiction in philosopher language um or you can predict properties of new elements that is look at those gaps and find something new in it and produce it as a law of nature to predict something new so these are all candidates different people have proposed each of these things as being an essence of the system so depending on what you choose you get an answer to the who question so the first candidate is Alexandra courtois who in the very early 1860s published in a French Mining Journal something he called the telluric screw the vitilariq which you can see here and he arrayed all the elements by increasing atomic weight and Drew lines through them and he noticed that there's a vertical periodicity in their properties so if you believe that you believe that number one and number two you end up with him being first and again there's the beard thing going on um John Newlands a Brit is another possible candidate he discovered what he called the law of octaves he classified All the known elements and he doesn't use atomic weight he just puts he assumes we know what they all are already and he lists them from one to n and he puts them in order and notices that their properties repeat every eighth element so he calls this the law of octaves based on music and you get the families going along this way which you know is very impressive uh William odling another British chemist comes up with a system that looks very similar and he's closer to number three um in that he classifies All the known elements and also he has a little bit number four he leaves some gaps where he thinks things should be Gustavus hinrichs is the Dane who moves to the Midwest and comes up with the first spiral system and then lotar Meyer who does four and five and then finally Mendeleev so depending on which of these things you think is most important you give credit to one person we now universally seem to believe that predicting new elements was The crucial feature of the periodic system so this guy gets the credit that's a decision we've made now that was not obvious to people then so I want to give you a brief history of how people have thought about these systems in the past and how we've come to give Mendeleev the credit and there's an interesting sub story a philosophically interesting sub story beneath that so um I'm not going to sit here and sort of say who's right and who's wrong I told you in the beginning I don't know and I wasn't kidding um but this is an interesting uh parlor game to sort of guess who's first who was who did it right what the periodic system is but it's not very good history and so we're going to do some slightly better history tonight hopefully and maybe make you like the periodic table a little bit more so this issue there's something odd happened in the 1860s right a whole bunch of periodic tables happened all through the 1860s there are none before and there are none after well at the end of the decade you have a table so there's no reason to have more but why were there so many in the 1860s the 1860s is an incredibly interesting time and there's a reason why all this independent Discovery happens roughly around this period so the fact that it's independent is in itself a little tricky issue because some of these people knew about other of these people when they published their systems so they're not all totally independent of each other but most of them didn't really know about someone else's system until they'd already started to work on theirs so what happened in the 1860s well in the 1860s in both inorganic and organic chemistry just about every concept every notion every theory was up for grabs everything was being revised and that's because a lot of interesting Innovations had happened in organic chemistry and interesting element Innovations had happened in physical chemistry such as spectroscopy being able to identify Elements by their spectral lines so huge amounts of new information happen in 1860 in September in Karl's rule which is a small town in the south of Germany um then south of the German states Germany is not a country yet uh there's a congress organized by an organic chemist named August kekule to try and standardize some of the concepts in chemistry because it's all too confusing we have 18 different formulas for vinegar no one can agree on anything we need to standardize this stuff because we can't teach properly if no one can agree with everybody else so he gathers call out internationally for chemists it's one of the first International conferences in a science it's not the very first but it's one of the first and um at this conference the star speech is given by this man stanislausaro an Italian chemist who later becomes a senator when the Italian State unifies um and kanitzado gives this speech saying we should revive his countrymen Amadeo Avogadro's 1811 theory about how to calculate atomic weights and if we do that and rigorously and vigorously apply it to everything we can standardize all the atomic weights so that everybody uses the same system that would involve changing some things so the atomic weight of carbon most people thought at the time was six if you apply Avogadro it's 12. oxygen goes from 8 to 16 and some of the ones get cut in half so you get all these new Atomic weights when you have all the atomic weights on the same scale it becomes very easy to order them in order and see the pattern so you need to have this particular speech and this particular standardization to happen before any of the reform can happen before you can have any periodic system but as soon as this speech happens people start making periodic systems all across Europe two people in in particular two young postdocs who were in carlsrua to listen to this conference uh later cited as incredibly important in their development their names are Dimitri Mendeleev and lothar Meyer both of them are there they don't meet each other but they both hear this speech and it triggers them on a path to find a periodic system there's another reason why they can discover why the periodic system happens in the 1860s and not earlier and not later there are very few Rare Earth elements that Island on the bottom of the table those have very similar properties so you don't see a periodicity with those the same way you see a periodicity with the basic elements and the transition elements so when there are very few of those it's easy to see the pattern in the system but if you try to incorporate each of those the system would look strange and people spend a lot of the 1870s and 80s trying to figure out what to do with these elements they thought a mentally I thought it was the uh the iceberg of the system the thing that was going to sink the system um so in the 1860s there's this unique moment when you have a lot of new information it's all standardized but you don't have too much information which is very important so you get six periodic systems within this decade none earlier and had they waited longer probably none later so what does this have to do with pedagogy this is sort of part two of The Talk uh I'm going to look at two particular textbooks written by these two guys here's Dimitri Mendeleev his textbook is called the principles of chemistry which comes out in Russian the first edition from 1869 to 1871. it has two very big volumes I'll talk about that in a minute and then Julius lotar Meyer comes out with a book called The Modern theories of chemistry in German that comes out in many editions the first is 1864. both of these books go through many editions that expand grossly in size over time and they become totems of Their Own Kind I'm going to focus on the Periodic system and how it emerged in each of these textbooks to change the question a bit not who discovered what but what did they want to do with it what do they want to do with the periodic system what they think it was for and that is something you can see and what it was for was for teaching students the question is what do you want to teach the students and that's different depending on who you talk to and that will give us a clue to one of the big mysteries in the periodic system which is why does this guy not predict any elements he has the system he has the gaps he fixes old elements but he doesn't predict new ones and the usual answer is to put a bluntly that he's chicken that he's not bold and this guy's bold and he's Bolder than this guy and this guy just doesn't do it that's not right um there's plenty and I'll explain why I think that's not right and this often gets tied in with a lot of nationalist stereotypes about Germans being cautious and Russians being Reckless all that stuff's not true um sorry if you thought it was true it's not um so let's start by talking about pedagogy for a bit and first let's talk about mendeleev's pedagogy both where he learned and where he taught he's actually very confined in place he doesn't go a lot of places Mendeleev was born in 1834 in Siberia a town called tabolsk when he um is college age his mother takes him to Moscow to try and enroll him at Moscow University to the oldest university in Russia he's not let in so then they go up to Saint Petersburg and try and enroll him in the University there he's not let in there either so he gets into his father's alma mater I'm not going to say anything in this particular context about getting in legacies but he went to his father's Alma Nevada uh which is the uh the chief pedagogical Institute which is located on the campus of Saint Petersburg University and has many of the same faculty members who teach in both places but it's designed to train teachers Mendeleev is trained to be a chemistry teacher uh he does very very well and he ends up getting the equivalent of he gets a candidate degree which is somewhere in between a doctorate and it's it's around a doctorate it's a little bit different than that but he gets that in uh in at St Petersburg University at the chief pedagogical Institute and then his advisor sends him off on a postdoctoral trip for two years from 1859 to 1861 to Heidelberg Germany and he goes to Heidelberg for a bunch of reasons uh there's a lot of chemistry happening there in that period of time the chief chemist there is Robert Wilhelm Bunsen but Hermann Von hell holds and Gustav kierhof both are there it's a very exciting place in the physical sciences Mendeleev doesn't study with any of those guys he uh spends his time in his apartment he makes a lab there and does interesting work on organic chemistry and he hangs out with one untenured professor of chemistry who I'll talk about in a little bit but mostly he hangs around with Russians and that one German guy um but he learns a lot of chemistry and then he comes back and after adjuncting for a while oh and while he's there Heidelberg is conveniently close to Karl's Rua so he ends up uh getting up he ends up going to Carl's Rua hearing the Congress he comes back to St Petersburg in 1861 in February two weeks before the Surfs are emancipated uh then he adjuncts for a little bit and gets a job in 1864 at the St Petersburg Technological University Institute Training Engineers he does that job for three years and then he succeeds his mentor at St Petersburg University in 1867 where his job is to teach General chemistry uh and so what he uh is supposed to do is teach that big intro class which is required for anybody in the Natural Sciences faculty uh and now he's got a problem uh because he has to give them a textbook so they can learn the chemistry that he has to give but the problem is that in 1860s all these Transformations have happened in chemistry and he doesn't have a Russian book he can assign so there are two basic options the first is to find an English or French or German textbook that's up to date and translate it he'd done that before for some other teaching jobs earlier but uh he can't really do that because by the time he gets it translated it'll be out of date because the Transformations are so rapid so he decides to write one of his own and that's where the idea for the principles of chemistry comes it's also more lucrative to have one of your own because you can assign your textbook to your students and you get royalties and and he he thinks about that very seriously becomes part of a divorce settlement leader but I'm not going to talk about that um so he wants to write a book the principles of chemistry and he's got a contract and it's a it's a fantastic book you probably have it here um it's got two volumes the first volume is designed to teach you the basic principles of how to think like a chemist that is how do you find oxygen how do you purify it in nature what is it good for what do you use it in where like Etc like which kinds of minerals have lots of oxygen content and so on and so what he does is go over 600 Pages as volume 1 and 600 Pages as volume 2. in volume one he goes lovingly over the four organogens hydrogen oxygen nitrogen and carbon and then in the last couple chapters he deals with the four halogens which is a known family of fluorine chlorine bromine and iodine and that's a family that everybody knows reacts the same way so he deals with eight elements in volume one and he's very happy with it and he sends it off in late 1868. to the Press so they can print it but now he's got to write volume two which has to be the same length and he's got 55 elements to put in the book and it's I don't envy him on this particular position so he has to figure out what to do so the first thing he does is put the alkali metals that column which has sodium and potassium in it because he knows those things everybody knows they're a family too so he deals with them and then he juxtaposes them together in around February 1869 exactly when is tricky and notices that the the increase in atomic weight between say sodium and potassium is similar to the increase of atomic weight between uh potassium that's between sorry chlorine and iodine and then he's like oh look at that it's almost the same increase of atomic weight these things are increasing at the same amount maybe there's a pattern here and he has this brainstorm and realizes that he can put other elements in groupings and find these similar patterns and he starts thinking about writing the group writing the book not in terms of individual elements in loving detail but families and that way compressing the book so that's the idea and he takes this idea and he produces this in February 1869. this is mendeleev's first periodic system he calls it a system it's not a table he never uses the word table it's like our modern table if you turn it clockwise 90 degrees and reflect it in a mirror and and instead of the weights increasing this way they go down and you can see that the families are here here are the halogens fluorine chlorine bromine iodine sodium potassium and so on you can see that he puts these These are the opposite ends of the table now the fluorine column and the sodium column and if you cut the table there and rip it apart you get our modern day table but he doesn't do that because he started by comparing these two and he builds the table out so you can see that the original table Bears the signs of its use in a textbook that's where he made it there's a couple of things that many things that are fascinating about this system I'm going to only point out three of them the first is that it's not done there's all these things over here that are not in the right order he doesn't know where to put them so we just kind of threw them on the end and said I'll deal with those later the second is that he has mistakes in it so uranium is right here with atomic weight 116. if you guys go to the nuclear talk uh very soon you'll learn that uranium has an atomic weight of 238 so it's about half so it hadn't been fixed yet later on Mendeleev fixes it he doubles it because he's like that's not right 116 can't be right and the third thing is that there are these question marks here at 45 here at 68 and here at 70. these are elements that he thinks are gaps but he doesn't just say Gap he says a gap and he predicts their atomic weight so the predictions are here from the very beginning it's extremely interesting by 1871 he finishes the book and sends it to the publisher and this is what the system looks like it's very much like our current system and it has an overleaf this goes out of the book so you can have it outside while you read the book so you have a periodic system that you can use while you read it's designed again for a textbook so it's an extremely pedagogically oriented table Mendeleev also always stressed that it was for teaching so repeatedly he talks about it in many instances so here's an example um quote I will add still another remark it is that the use of the periodic law facilitates the learning of chemical facts by beginners which is what we still use it for I have come to this conclusion during the courses of lectures that I have given for two years and during the preparation of my triteage in organic he says it in French now published in Russian which Treatise is based on the periodic law that's written in English that article um so Mendeleev was a very flighty and very difficult person and a very um cantankerous colleague but he was extremely dedicated to undergraduate teaching and that's what he thought this was for but the fact that it's for teaching and embedded in a textbook highlights also some features of mendeleev's conservativism pedagogically he likes the table because the table doesn't require you to make any hypotheses this sounds a lot like Newton he writes a letter to Emil Erlenmeyer the German chemist in 1871. I want only that you will pay attention to the fact that I do not set up any hypotheses because in my view these often seduce students as false keys and thus tends to slow down the development of science that's extremely interesting because Mendeleev is basically hostile to most chemical theories uh he's skeptical towards atomism and valency which we think the periodic system now is about correlating atomism and valency a mentally I thinks both are dodgy he doesn't like the idea that atoms have substructure that they might have something like protons and neutrons that make them up that's called prout's hypothesis in the 19th century he thinks it's wrong he doesn't believe in the electron when it's discovered in 1897 he doubts the existence of noble gases when they're first discovered in 1894 eventually he accepts those and he doesn't believe in radioactivity even though he visits the curie's labs generally Mendeleev is consistently hostile to chemical speculation which is extremely interesting and that pedagogy it's pedagogical in orientation he doesn't like theorizing in front of students because students like The theories too much they don't have the right skepticism towards it and the table is perfect for this right because the table doesn't have any explicit theory in it it's just an ordering of elements by atomic weight and they can use it to think chemically without getting seduced by hypotheses there's one exception to mendeleev's pedagogical conservativism it's kind of a big exception but notice that Mendeleev in all of these things he's on the wrong side right like every time he makes a decision he's wrong um that's interesting because this is we've forgotten all about this because the one exception is so important and that is that Mendeleev predicts elements and he's right three times stunningly he never thought it would happen this fast but in 1871 he publishes the system with the full predictions very detailed what kind of crystalline structure they'll have what the density of the elements are going to be their specific Heats their weights their valency or their combining power which is what he uses through oxidation level in 1875 uh the bubbledraft discovers gallium in 1879 another element is discovered called Scandium that's discovered uh this is discovered in France Scandium is discovered in Sweden Norway and germanium is discovered you can guess in 1886. um this nationalism is a theme that runs through the rest of what I want to say today uh so uh so this is an extremely uh theoretically bold thing to do I mean he is kind of bold in doing this but he's not theoretically bold in almost any other context and he doesn't do this in the textbook he does this In Articles it's not for students this is what you can do to chemists but students be very very conservative with he also has a theory of credit that he embeddeds in his explication I don't want to get into this very much but he um has a vision that you should give credit love was Jacob's credit for oxygen because love was yet discovered it or explained it in the most comprehensive way even though Priestly found the substance first so likewise if other people found a table first but didn't predict they didn't fully understand the system and so he should get credit for it he uses history for that purpose too so uh and therefore if it's full credit that's the really the issue that's extremely important then we know who should desert get credit for the periodic system the person who makes predictions which is the furthest implication you possibly can have and we know who that is it's not lothar Meyer Luther Meyer didn't do that so let's talk about lothar Meyer's particular pedagogical Origins it's very different from Mendeleev Mendeleev was Petersburg a little bit of Germany and then Petersburg for the rest of his life Meyer is very characteristic of German Chemists in that he went everywhere and learned different kinds of chemistry from different people where he went it's very common in 19th century Germany academic freedom means you can go from place to place to place and study a semester here a year there or semester here take courses with different people and he learns different kinds of chemistry physiological chemistry physical chemistry he learns spectroscopy he learns organic chemistry so he moves around he starts in Zurich he's a little older than Mendeleev but he was sickly as a child so he was held back so they're almost exact contemporaries uh Zurich he works with a guy named louvig wurzberg with verifao who's a very important man in cell theory at Heidelberg he goes there not overlapping with Mendeleev really where he works with Bunsen then he goes to koenigsberg and learns some physics and while he's in Heidelberg he also manages he's nearby and he goes to the Carl's rule Congress so it's very itinerant likewise his pedagogical jobs are very itinerant he starts out in Breslau in 1859 which is uh was the oldest university in Prussia I believe it's the oldest one in Prussia now it's in Poland called rozzwav uh but he's there for a few years then he goes to a forestry school at neustad ebergevalda then he goes to a Polytechnic School in karlsruhe teaching Engineers similar to Mendeleev and in 1876 he ends up at tubingen a major research University where he stays the rest of his life so he's very itinerant in this particular process and that's um interesting because he's learned first of all he's learned lots of different kinds of chemistry and then he has to teach lots of different kinds of students and so he is actually very attracted to chemical Theory like atomism and valency because it's useful to teach different kinds of students the basic principles of how to think chemically and so he's extremely excited by atomism and valency so in 1864 he publishes the first edition of modern theories of chemistry it's 137 pages long it's not very big book it's very much unlike mendeleev's the whole point of this book is to juxtapose atomism as one Theory and Structure Theory in organic chemistry to illustrate valency as another theory so he has part one and part two and then they fuse together at the end when he produces this thing which is a periodic table here it's uh four these are valencies four three two one one two and here you have carbon nitrogen oxygen fluorine fluorine chlorine bromine iodine you have all these and he marks the differences in atomic weights between the levels and he notices that it's about 16 to 17 here between these two levels here it's 44 to 46. so he's doing the same thing Mendeleev did in 1864. he doesn't have a full table but this is the basic idea and he's extremely excited about this particular system because it unifies the two theories and things are interesting and you think students should learn about them it's half a textbook and half a polemic with other chemists to say don't dismiss Theory it's really important and in 1872 in the second edition he produces this and that's just that's a periodic table right like that just looks like our periodic tables in the way we would have them now he also in 1870 publishes an article and this is what he's famous for where Mendeleev never did this which is atomic volumes and he has a curve of their atomic volumes and the shape of this curve is periodic it has a structure that's very periodic in it so after Meyer does this theoretical thing you think he's going to predict elements right because he's incredibly bold and very theoretically sophisticated but he doesn't this is what he says right after uh publishing it uh printing the table the first table it is surely not to be doubted that a definite regularity prevails in the numerical values of atomic weights it is rather improbable that it is as simple as it appears if one leaves to side the relatively small deviations and the values of the evident differences impart indeed these deviations can be part of experimental error but this can hardly be the case for all of them and entirely certainly one is not justified as is seen all too often due to a suspected regularity to want to arbitrarily correct and change the empirically determined Atomic weights before experiment has set a more exact determined value in its place this says don't predict anything based on this I know I have two really good theories but experiment's incredibly important don't get carried away don't speculate so after defending theory for so long he wants to not scare off his colleagues and say look don't go too far it's important to be a little conservative in predicting because we don't know how certain our theories are atomism very certain Theory this table not a very certain Theory so don't rely too much on it and that's interesting because Meyer is pedagogically incredibly radical in modern theories 1864 he endorses atomism valency the idea that atoms have substructure Structure Theory all things Mendeleev doesn't believe in uh and he's right on all of them on every issue which he predicted which Theory where he stated I believe this Theory we agree with him and with mentally if we disagree the interesting thing is that prediction point it's just it's a sticking there it's very difficult to deal with because he doesn't predict anything so why is that when we have a paradox here Mendeleev is incredibly conservative about Theory yet he'll predict he thinks that's okay yet Meyer is incredibly radical on Theory he's at The Cutting Edge but he excludes prediction he says that's not okay so why why is that well I think there's two reasons for that the first is the border between chemistry and physics Meyer is very careful in the book to say these are chemical theories atomism and valency they're not like the theories in physics they're not like Newton's Laws and as a result physicists predict that's what they do with their theories we explain with our theories we do something different and so he's very important very interested in setting up a boundary between chemical theories and physical theories Mendeleev always flirted with physics he was always incredibly interested in it and he's trying to erode that distinction between the two disciplines and so the prediction is part of him saying I'm like a physicist I can do the kind of thing you do so there's a deep difference in what they think chemistry is for and you can see that and how they treat their table and the second is about the pedagogic goals they have mendeleev's goal remember is to teach chemists how to think like a chemist teach young students how to think like a chemist and to do that you don't want to seduce them with theory in chemistry articles in journals You can predict all you want because responsible people will read those but you don't expose students to that stuff Meyer is the opposite Meyer thinks you should teach students a proper respect for Theory and part of a proper respect for theory is not going overboard so you can see the pedagogic origin in the table itself so that's what I wanted to say on part two I just think we shouldn't you know be a little too harsh on Meyer Meyer has a whole project here behind not predicting and it's part of what it means to be a responsible teacher Okay the third part of the talk is what I'm going to start now and I want to talk about why this happened why there's a fight between Meyer and Mendeleev right now I've made it sound like they've have like different views but as if they don't talk to each other they talk they write against each other they scream it's extremely vigorous angry fight so why did this happen well it happened because of one word uh so it happened with one word because of this man this man is Friedrich Conrad balstein he's born in 1838 in Saint Petersburg of a German family that lives there he's fully bilingual Russian German and gets educated in for graduate work in Germany and he stays in Germany for a while but he's still very tied to the Russian chemists he eventually goes back to Russia in 1866 and takes up mendeleev's old post to the technological Institute he's the editor of a so he's in St Petersburg in the late 1860s he's also one of the editors of the titrift for hemian pharmacy the Journal of chemistry and Pharmacy which is a German chemical Journal it's not the major one it's a small one but it's one that people do read and he's very eager to get Russians to publish in it so he tells Russians all the time please give me your articles I'll have them translated we'll publish them in German that way people will read you because no one can read you in Russian no one knows Russian so no one who matters knows Russian so they'll read German and that's true in this period um so and for a variety of reasons Russians like the publish in this journal they like to publish in it even before biostein I'll get back to that in a minute so biostein's really busy as is his want and so he has to do a bunch of different kinds of things so he does what most people most Chemists in his position would do is he gives it to a grad student to translate um a guy named ferrisman uh and ferrisman is translating it really quickly and he makes a slight mistake in the translation so Mendeleev says when the periodic uh when the when the atomic weights increase there's a periodicity in their properties they change perid periodically and period is in there so it's really periodic based on math that's the analogy and instead of translating as periodis first man translated as a schofenweiser which means step wise or gradual so Meyer reads that in this 1869 abstract in the title for human Pharmacy which says there's a longer article in Russian but this is an abstract of it Meyer reads it and says oh well Mendeleev is so close he knows that there's a change and the table is very good but it's not gradual or step Wise It's periodic so he writes an article saying Mendeleev is almost there it's periodic and so he goes one step further uh mental AF is kind of incensed he's like what do you mean I said periodic and Meyer says well you know but I read the thing and it says here's gradual and he says well you should have checked the original you knew it was an abstract of something else and Meyer says well there are several priority disputes that start after that the first one which is in 1871 is very very hostile takes place entirely in German and it's basically Meyer saying I don't have to learn Russian come on it's ridiculous I have to be German French English Italian and Swedish enough if we had to learn Slavic no one's going to do anything we're just going to spend all our time reading languages it's awful this obviously doesn't play well in St Petersburg as a strategy um so there's a very nasty dispute that happens this way and bilesh line because he's responsible for the translation he doesn't sell out the grad student he takes responsibility and they never trusted Palestine anyway because he's German they think he's German so uh so it gets very nationalist very quickly and then it dies down by 1873-4 and then in 1880 Adolf Wertz just can't leave it alone Adolf Wertz is in at the sorbon in Paris um he's an Alsatian chemist he's bilingual French German uh and he uh earned the ire of the Germans in 1868 by publishing in the dictionary of pure and applied chemistry the opening line chemistry is a French science grounded by love was yeah the Germans find that not very funny um so there's a big fight that happens in the late 1860s again about who is more chemical and then in 1880 verts writes a letter to the the baritha of the German Chemical Society the leading chemistry journal and says you guys keep saying that Meyer discovered the periodic system but he didn't Mendeleev did he did it first and that gets everybody really mad again because the Germans are mad at this like french guy tweaking them again and trying to steal their credit the Russians get involved again and it just it's very bad and so then in 1882 the Brits tried to step in and solve it and they do temporarily solve it by awarding the Devi medal to both of them so here's the Davey metal and the Royal Society uh gives them to Dimitri moves Mendeleev and lothar Meyer and this is great right because it's alphabetical but Mendeleev is first so it just it does everything so this works for a while by the 1890s after the predictions are all discovered we all everybody changed their minds about what the table was about and they think it's about prediction so then they give all the credit to Mendeleev but in the 1880s that's not obvious yet so everybody thinks it's about something else and they think they both deserve some kinds of credit so why did this happen like what's a huge mess why why did this take place well I'm going to rephrase the question this happened because Mendeleev published in the titrift for hemian pharmacy he published in that German Journal a translation of a Russian abstract of a Russian article why did he do that he didn't just do it because bauschline asked him to right like because Bob he could have published in other contexts he published in that journal specifically because of something that goes way back to Heidelberg remember I mentioned that Mendeleev went to Heidelberg in 1859 to 61. uh very many Russian academics uh postdocs were sent abroad in this period a lot of the Physicians end up going to Vienna a lot of the law people end up going to Bonn or to Berlin and the chemists predominantly end up going to Heidelberg and there's a little colony of them there and he goes there but while he's there he goes to the Carl's rule Congress but mostly he hangs out with Russians and I said one German that one German is Emile Erlenmeyer emulator is incredibly interesting he's a very theoretically flashy man and he's the editor of the titrift fork immune Pharmacy he's the editor of this particular Journal and the Russians like him he's the only German they don't think is snooty they have a nickname for him yetimich which they he is a term of endearment they correspond with him uh in German and they really quite like this man the Germans don't like Erlenmeyer because in erlenmeyer's journal he publishes their articles and then he writes uh puts footnotes in or even embeds in the texts uh sarcastic remarks uh question marks and so on and he does that even when they didn't publish with him he translates an article from French he puts it in the journal and makes fun of it and this means that no one in Germany reads the side trip they don't like it its sales go down the only people who still read it are Russians because they him and they did know that that was weird so because of their friendship with this guy this is not because the Russians are crazy or dumb or something it's just they know this guy he's very nice to them and they think this is a perfectly fine way of being a chemist because that's what they're learning from him and then in 1865 no one's reading the the the um the article the the side trip so it goes to guttingen it moves away from Heidelberg and then it goes to biostein and two friends they and then Palestine goes back to Saint Petersburg and so the Russian connection continues throughout this period and because of that Russian relationship with this particular Journal Mendeleev is predisposed to publishing in German in this particular weird context which is why he ends up in that journal with that particular translator at that particular time so it's a bunch of very small local relationships between lots and lots of different scientists not very few different scientists both in Germany and in Saint Petersburg that produces a periodic table fight about nationalism it's not because the Russians hate the Germans it's because Mendeleev doesn't like biostein very much but he likes Erlenmeyer and Lynn Meyer has this other relationship with verts it's this very intricate narrative story that we now flatten out and say Mendeleev discovered the system first Meyer didn't and interestingly even though Mendeleev really wanted to have credit for the periodic system that's not the only thing he wanted he he was 35 when he did it and he thought he was going to do much better things later so he wanted always to be something more than just the guy with the periodic system but that's not what happened everybody forgets the stuff he did later this is a statue of him in St Petersburg it's the only statue of him in St Petersburg and he's sitting looking on moskowski Prospect which is the road that connects St Petersburg and Moscow looking at the St Petersburg technological Institute his first job and on the wall behind him you can see there's a periodic table he's sitting in front of the Bureau of weights and measures where he had been director to introduce the metric system into Russia no one remembers that they just remember the system so the whole priority dispute succeeded all too well anyway thank you for your attention [Applause] oh I have a microphone we'll have two microphones for questions and we're also going to turn up the house lights any questions okay let me come around this side in a scientific writing today is it a hundred percent in English or is there still a Leading Edge uh research and and writing in other languages um it depends on the science but in general it's about 97 to 98 English that Trend so by 1980 it's 80 English 14 Russian everything else the other languages in 1880 so a century earlier it was a third or third a third and Russian wasn't on the board French English German Russian is like tiny um now it's almost all in uh English but that's not true in every field mathematics is not quite as anglo-centric I don't know the exact figures but it's below that number and there's a lot of French and German stuff still produced much of it gets translated but some of it doesn't and in certain Fields like astronomy there's still Russian that matters um but even the Russian mathematicians many of them now publish in English there's been a Tipping Point and that's where the transition happens but the transition started to really take place in the 60s that's when you start to see a real transition but for a while Russia was on the rise Japanese was on the rise it's a it's a very complicated intricate story but it's um it really does depend on the science chemistry was overwhelmingly German in 1900 and now is overwhelmingly English and when you have people publishing people still publishing journals but they publish in Chinese is and in English so there's always an English version of the article that they produce because they want to be cited in red and that was also true in the 19th century just you would publish in German and French and English the same piece so different people would read it it's just now English is always the reserve language that's a great question I'm a physicist I'll just say as as an aside I graduated in 1979 and one of my pains was having to learn Russian so I could read articles but you're you're one of the last actually one of the C's I ever got in college this phenomenon of things being discovered by different people often far separate in different places recurs throughout science and I've heard it described actually that it's a it's a completely post facto effect is that we look back and we think we see this but maybe I know this is a little far afield from what we've talked about tonight but the best example I know of would be Newton and leibniz who really had as I understand essentially no contact can you can you talk a little bit to that well they had essentially no it's it's kind of complicated they had no they had we thought they had no contact it turns out that leibniz actually had a copy of a manuscript by Newton and annotated it and now we know that but nonetheless he did a different system if you look at Newton's calculus and leibnizes calculus we can't do Newton's calculus anymore if anybody remembers ever doing x dot and X double dot that's Newton's notation uh it's terrible the DDX thing that's leibniz so they're very different kinds of systems and they wanted to do different kinds of things with it but um that kind of phenomenon where people could discover the same thing at the same time it's some of it's post facto where we look back and we see things that look similar and say they're the same but some of it's very real because people know what the Cutting Edge questions are so they're all working on it and whoever gets their first wins so we have a system of credit that rewards firstness it doesn't necessarily reward bestness it rewards who gets there first um and that's a very important feature of science today this credit system so with um with leibniz and uh and Newton we don't Focus as much on we want to know who did it first we want to know who did which part of it first but we don't Focus so much on what they thought they were doing and that's something I think we should pay more attention to but there's plenty of other examples of this kind of thing and and for leibniz and Newton we don't have a publication because they didn't publish their stuff they had letters and they told people now the standard is published who published his first wins uh interestingly so leibniz thought leibniz thought he didn't get enough credit for calculus so he thought he should get more credit he also wanted a job in England because his boss became the king of England so he wanted to move to England from Hanover so he asked for an adjudication of who got the calculus first and he asked the Royal Society of London to decide it first the president of the Royal Society of London is Isaac Newton so I I don't know what you guys know about Newton but Newton was not a nice man um so it's uh it was it was no take no prisoners very um leibnitz didn't get the credit uh is the short version of that but so this this anxiety goes back a long way there's lots of elements of this you even see elements you start to see elements of it very strongly in the period that we call the Scientific Revolution this kind of Copernicus to Newton's Zone but it is your example is one of the classics this is another classic one that's even weirder because there are six of them it's just a proliferation and that's quite common they're about they're like at least three to four people who are pretty close to the structure of DNA in 1953. and we only give credit to two of them and we give the third guy a Nobel Prize and the woman died and so she couldn't get a Nobel Prize so that but then but Linus Pauling gets no credit like so this system is very interesting in its structure but thank you for the question the periodic table is always appeared to me to be upside down because the ACT tonight's Decay to more stable elements below uh above on the table and we're still looking for hydrogen atom uh uh nucleus to Decay so has anyone thought of uh correcting that oh people have done every everything you can imagine has been done with the table it's been oriented upside down there are cases uh and I kind of like this one so this these two series belong here they're the lanthanides and actinides they belong right here some people have 3D Systems where this thing is tilted out of the board so that way you they all belong where they belong people separate it by Quantum shells whether it's like they separate them out by SPD orbitals people have done everything people have inverted it people sometimes reproduce hydrogen over there and hydrogen all the way over here by the halogens because it's basically both so yeah people have done the inversion of the system but this is the one that catches on this is the one that fits on a wall and this is and that's not trivial right the 3D one doesn't fit on a wall no one wants to use that so there's lots of reasons why this gets stabilized but by 1930 this is stable Mendeleev never uses this system he doesn't believe you should have this Valley in the middle so he thinks there should be a seamless across so he intercalates these three periods here half periods here of the transition metals in between the other ones and you get other patterns when you do that more chemical patterns this one is designed the way it is because of quantum theory we believe that this reveals certain things about quantum theory uh in terms of what you said about um you know mendeley of getting credit today uh it sounds like that is uh really related to the predicting elements um so had there not been the whole priority dispute if he'd published in German originally do you think that would still be the case that Mendeleev would get would get credit uh you mean if he published in German and not made the predictions or no if he published in German and made the predictions you know but hadn't had this whole sort of uh very caustic you know back and forth would he still get the credit today this is so these are counter factuals I'm sort of I have to be officially opposed to them because they didn't happen so it's not in the past it's a guess about the past but I I'll play along and answer what I um so I he would have definitely gotten some credit because at the time when the debate is happening people would have still wanted credit for it and whether or not Meyer wanted to start a fight Meyer seems from his correspondence to be a reasonably peace loving easy going guy other people would have claimed credit for Meyer for the sake of Germans and other people would have claimed credit as they did for the sake of France they claimed that courtois did that so other people would have made it nasty but I think if there hadn't been a translation mistake and he published it normally he would get credit whether he would share it or not share it depends on um a lot of things in particular how much we value prediction and as chemistry becomes more and more like physics not a separate science but part of a joint physical sciences a joint physical science that the standard of of uh credibility the standard of validity changes and I think that changes what gives him the credit so it would have happened even if there hadn't been the fight probably because that transition was happening due to a variety of Transformations but again I officially can't guess oh being a history major I need to inject something else since Germany really wasn't a country until 1870 yeah there might have been a fear to predict between 1860 and 1870 exactly what was going on where Russia at the time was going through a vast Eastern expansion conquering various native people similar to another country going Westward yes so a lot of analysis they both have slavery issues in exactly the early 1860s could that have had an impact do you think on their thinking uh the the Russian expansion or the German lack of unity prediction versus um I don't think so it's interesting thought but I don't think so because I don't think I can I can speak more about Mendeleev because we have more documents for him he does in this period of time he's pretty detached from Imperial politics he's very interested in what's happening locally in St Petersburg and there's a lot of uncertainty in St Petersburg too if you push this this way because there's an attempted assassination on the Czar in 1866 it almost Works uh it does work in 1881 uh Alexander II is assassinated so um there's a lot of uncertainty in the 1860s as well Mendeleev starts out with a job at St Petersburg University and then there's a student rebellion and they shut the university down for a year and a half that's in the early 1860s so he he experiences uncertainty as well doesn't look as certain as it does to us now on the other hand the Germans while they aren't a country there's a German Chemical Society before there's a Germany uh because Deutsche like means something germanness has a cultural unity in a way that actually russianness in this period does not Russia is a multi-ethnic Empire with an enormous diversity of peoples in it and so we uh later on Russia becomes much more especially in its later Soviet incarnations and today much more ethnically conscious than it is in the uh the mid uh 19th century but it's a very interesting thing to think about because this stuff does pop up that is why those elements are named after countries they're named after countries to declare something about their position that that Germany is a place that should have an element after itself Russia has an element too Russia is ruthenium uh which is that that there's withinium right there element 44. uh because that comes from the Latin word for Russia um but that was discovered by a german-speaking person working in Saint Petersburg uh in the early 19th century I want to say 1830s but I can't be specific about that but that's part of declaring Russia a scientific country that matters too so there's there's politics all over this but I don't know if I would be so um so uh deliberate about putting those linkages together okay back here Dr Gordon and due to the time this will have to be the last question uh hello thank you I enjoyed I enjoyed I uh in the back um you mentioned that everybody knows what the questions are what the pertinent questions are in science and it's easy to understand today how that would be because there's an increased flow of information people can communicate and you know we know where the money is but at that time how did people know what the pertinent questions were and what was at The Cutting Edge uh they so people when you first said that I was like did I say that no now I know what you mean yes I did say that and I mean that um people knew that because there were certain topics that they knew were burning this was not one of them when it first came out the periodic system is a byproduct of writing a textbook but certain questions like what the structure of benzene is Benzene was problematic people just didn't know what to do with it and so in journal articles and it's of a much longer time frame but people do read the German the German or the French or the English Journal articles and so over the course of a decade there was an obsession with Benzene people just know this is a problem and that attracts people's attention but it's much slower the issue of uh the the transformation of species people have been gnawing at that particular bone for decades Darwin had been gnawing at it for decades before publishing I mean like everybody had been worried about that he was worried about in the 1840s it didn't publish until 1859. um uh 1858 59 depending how you count um but uh and there was a priority dispute there as well um but but there are certain topics that kind of stand out but otherwise ones like how heredity works that wasn't a burning question Mendel publishes on it and no one cares because it's not a burning issue so but some issues stand out and the issue of how to calculate um a law of gravitation from the trajectories of planets that's a question that's called the inverse problem people are very very worried about that particular problem they know that if you have a central Force you will get elliptical things but they want to know if you have elliptical things do you get a central Force people are working on that extensively to solve it you need to invent calculus so there's a there's a push towards certain kinds of questions but not by no means is there unanimity and there isn't unanimity today there are some questions that we think are really crucial and then there are some people who think it'll be really interesting to know what caused ulcers not an important question that guy got no funding and no one cared about it and then you got a Nobel Prize because it's pretty amazing but he had to experiment on himself because nobody would actually give him any funding um but but but so some questions people will still work on anyway but other questions are really pushed at by the by the by the mechanism and the nature of the time but it's a great question it's much slower but I think still a very recognizable process thank you doctor thank you all very much and thank you for attending tonight's lecture remember next week next Tuesday we have a wait list for the first Nobel Laureate lecture with Carrie molas but next Thursday the 21st nuclear safety America's approach there are still tickets available please go online at lindahall.org thank you and good night

Channel: Linda Hall Library

Views: 1,896

Keywords: science, engineering, technology, history of science, periodic table, Dmitri Mendeleev, Lothar Meyer

Id: hzRTJ75ZpvQ

Length: 57min 58sec (3478 seconds)

Published: Thu Apr 27 2023