Friday, 1 April 2016

Matthewisms dismantled

Mike Sutton is a reader in criminology at Nottingham Trent University who has used google, in order to track down the provenience of certain quotes that are often misattributed. He now thinks he has sufficient evidence to conclude that both Charles Darwin and Alfred Wallace plagiarized Patrick Matthew (1831. On Naval Timber and Arboriculture) and stole Matthew's idea of evolution through natural selection from it.

One part of his exercise in logomachy (Sutton 2014, chapter 4) was to find phrases in Matthew (1831) that were apparently never used before. Concluding that Matthew was first to coin and use these phrases (called Matthewisms), authors who used the same phrase afterwards were taken to have them from Matthew (1831). These authors were called first to be second.

The following authors were all taken to probably have the phrases in question from Matthew (1831), the implication being that they all read Matthew's book and, if they don't cite Matthew, betray this by the use of the phrases in question. The list below is list 2 from Sutton (2014, chapter 4) with comments added, were Sutton's premise is evidentially false.
  • 1832 — Mudie: "rectangular branching"
  • 1833 — Ellerby: "plants so far asunder"
  • 1835 — Main: "luxuriant growing trees"
  • 1834 — Conrad: "admixture of species"
"Mêlange d'especes" was a very common phrase in French science and it is very old. It can be found, for example, in M. Bertrand's Eléments d'Agriculture, from 1775, or in the Encyclpédie Oeconomique ou Systême Général d'Oeconomie Rustique from 1770.
  • 1834 — Roget: "living aggregates"
Matthew (1831) was not the first to use that phrase, though the original use was, again, in French. Cuvier wrote about the "agrégat vivant" in 1829 (see here).
  • 1834 — Low: "long continued selection"
  • 1836 — Rafinesque: "evinced in the genus"
Rafinesques (Flora Telluriana, p. 95) wrote:

"To unite in the single Genus, Carex, plants with 2 or 3 stigmas or styles is still worse; and not to perceive that such a Genus of 300 Species is a fine Nat. family with many Genera distinguished by this and the seminal covering, proves that the absurd linnean principles evinced in the Genus Lichen now a Class! prevail as yet among us. Whoever preserves Carex entire ought to keep Lichen and Agaricus entire, and make a single Genus of Ombellifera."

Compare this with Matthew (1831, p. 107f):

"May we, then, wonder that our plantations are occupied by a sickly short-lived puny race, incapable of supporting existence in situations where their own kind had formerly flourished—particularly evinced in the genus Pinus, more particularly in the species Scots fir; so much inferior to those of Nature's own rearing, where only the stronger, more hardy, soil-suited varieties can struggle forward to maturity and reproduction?"

Why should Rafinesque take his phrase, used to rant against the Linnean system, from Matthew using the same phrase, in order to say something about the degeneration of cultivated plants. And even if he read the phrase in Matthew (1831) and it stuck to his sub-conscience, and it later emerged when writing, what's the point of such psychologising? A phrase that is picked up somewhere and regurgitated in a different context. What can it signify? The phrase transports nothing. That, however, is exactly Sutton's logomachy that he claims that the phrase is the concept (e.g., here and here).

The slightly longer phrase: "proves that the absurd linnean principles evinced in the Genus Lichen now a Class! prevail as yet among us," however, is a very different concept from: "our plantations are occupied by a sickly short-lived puny race, incapable of supporting existence in situations where their own kind had formerly flourished—particularly evinced in the genus Pinus."
  • 1837 —Wilson: "threatened ascendency"
  • 1837 — Anonymous[31]: "nature's own rearing" [Endnote [31]: Spectator Journal.
This is from page 946 of The Spectator (No. 484, for the week ending Saturday, October 7, 1837). Sutton, again, fails to even look at the headline, which would take some scrolling because it is one page 945. In fact, the headline says 'The Theatres.' That is, the context of this phrase is a critique of the play Winter's Tale given at Covent Garden: 

"It is this false system that makes mere puppets of so many actors; in particular, it has spoiled two clever young ladies of the Covent Garden company, Miss Helen Faucit, and Miss Taylor. Miss Taylor's Perdita was not the simple shepherdess, but a court lady assuming the character: instead of a flower of Nature's own rearing, we were presented with an artificial imitation—and not a very good one either."

Are we to believe that the author of this critique must have taken the phrase of "nature's own rearing" from a book on naval timber or that a reader of this critique somehow got wind of Matthew's book from this critique? 
  • 1837 — Dovaston: "sport in infinite varieties"
  • 1838 — Anonymous translator: "portion of the surface of our planet"
As already shown, under the fourth and fifth point (Conrad 1834 and Roget 1834), missing the original of a translation can be fatal for an ostensible Matthewism. Hence, it verges on empty-headedness to give the author as "Anonymous translator" without trying to find out what that original actually was.
  • 1840 — Buel: "infirm progeny"
  • 1840 — Swackhamer: "beat off intruders"
  • 1841 — Johnson: "adapted to prosper"
  • 1841 — Hill: "deeper richer soil"
  • 1842 — Selby: "greater power of occupancy"
Selby (1842. A history of British forest-trees) cites Matthew (1831) on about 25 pages, but only one of these citations is not about technical matters such as timber quality for human purposes, pruning, trenching, planting, treating seeds etc. This citation is at page 391 and it actually rejects Matthew's idea about greater power of occupancy:

"The soil upon which most if the Abietae prevail, is usually of a dry and cool quality; thus, the débris of granitic and other primitive rocks, and barren sandy districts, are very commonly occupied by Pine and fir forests, sometimes of enormous extent; the thick and close manner in which they grow, and the dense shade they produce, effectually preventing the vegetation of other species. Matthew, however, in his able treatise on naval timber seems to think that its indigenous location in such districts arises not so much from preference of soils of the nature above-mentioned, as from its having more power of occupancy in such soils than any other plant of the country; and this opinion he endeavours to support by stating that the Pinus sylvestris, planted in a good or rich soil, attains larger dimensions and its best timber properties, and that it is only driven from this superior soil by the greater power of occupancy, planted in a good or rich soil, attains larger dimensions and its best timber properties, and that it is only driven from this superior soil by the greater power of occupancy possessed by the oak and other deciduous trees, an opinion in which we cannot altogether acquiesce, as we see no reason why the fir, if it grows with such additional vigour in a richer soil, as Mr. Matthew asserts, should, at the same time, be unable to maintain a contest with the oak or other tree." (Selby 1842, p. 391)

Obviously, Selby did not understand the relativity of growth in a richer or poorer soil. That is if the pine does grow better in rich than in poor soil, but the oak grows still much better than the pine there, then the oak will oust the pine from the rich soil. If on the other hand, pine grows worse in poor than in rich soil, but still better than other trees, it will exclude the other trees from poor soil. In modern parlance, soil quality would be called a dimension of the ecological niche (/niːʃ/).

While it is obvious for us to see, in retrospective, that this insight about ecology (competitive exclusion) has been inspired by MAtthew's thinking interms of natural selection abd competition between trees, his contemporaries did not have our retrospective vantage. Selby obviously failed to get Matthew's idea, here. If this proves anything, then that Selby did not receive (read or understand) Matthew's exposition of the idea of natural selection in the appendix. It surely shows that Selby read Matthew (1831) as a work on technicl matters of tree planting, training etc., because 24 of 25 pages that cite Matthew, do so on technical matters.
  • 1844 — Low: "overpowering the less"
  • 1846 — Emmons: "habits of varieties"
  • 1846 — Alabama Supreme Court: "Infirmity of their condition"
  • 1848 — Charnock: "stiffest and most obdurate"
  • 1849 — Emmons: "deteriorated by culture"
  • 1852 — Wilkin: "figure is best accommodated"
"Figure is best accommodated" occurred in a book called "Sir Browne's work: including his life and correspondence" edited by Simon Wilkin and published in (1835). Sutton simply overlooked that this phrase is not by Wilkin (1835) but by Browne (1658). Wilkin just assembled the works of Browne, edited and republished them. This Wilkin-Browne case was first published in a brilliant rebuttal of Sutton's book by Grzegorz Malec (see here).
  • 1853 — Andrews: "impressions and habits acquired"
  • 1854 — Mure: "dogmatical classification"
  • 1855 — Fishbourne: "power to permeate"
  • 1855 — Laycock: "mental or instinctive powers"
  • 1856 — Gazlay: "adaptation to condition"
  • 1858 — Powell: "restricted adaptation"
  • 1858 — Floy: "law manifest in nature"
This is from a sermon by Dr. Hallock recounted in The National Magazine: devoted to Literature, Art, and Religion, vol. 13, p. 183, (vol 12 ends with page 572 and vol. 13 is concatenated). The editor Floy summarizes Hallock's divinations (beware, lots of spiritualist BS): 

"The Road to Spiritualism, in four lectures delivered in the New York Lyceum, by Dr. Hallock, author of "The Child and the Man." [...] Dr Hallock, the high-priest of nature says: "Bring before the man who holds this key these empire-splitting and world-convulsing questions which have vexed it so long, and mark what he will do with them. Ask him: Ought I to starve my body to a skeleton, or mutilate any part of it, for the glory of God and the good of my soul? Should I be a Shaker, or a Mormon, in my relation to woman? He asks you, Are these practices physiologically and socially right? You answer, No. Then they are theologically wrong, and no authority can save them from ultimate disgrace. Physiological, theological, and every other law manifest in nature, must accord, if from no other necessity, then from this, that they have a common end, which is, the development of man."

That is, Hallock simply thought that both the polygamy of the Mormons and the celibacy of the Shakers were unnatural—against the law of physiology, theology and every other law manifest in nature.

This is an embarrassing context for Sutton, and it has absolutely nothing to do with Matthew's law of degeneration: "There is a law manifest in nature, that when the use of any thing is past, its existence is no longer kept up" (Matthew 1831, p. 367). Why should the fact that Floy (1858), in parroting Hallock's gibberish, happened to use the same phrase as Matthew did before, signify that Floy must have read Matthew (1831)?
  • 1858 — Leidy: "impressions in insects"
This is from the Summary of the Transactions of The Philadelphia Biological Society: reported by Henry Hartshorne, M.D., Recording Secretary." As it is published in the Journal of the Lousiana State Medical Society (1858, Vol. 15, p. 673-679), these two societies seem to have had reporting secretaries traveling to and fro. That is, the transaction may have taken place in Philadelphia and only been reported (by Hartshorne, not Leidy) in the Journal of the Lousiana State Med. Society. [Ht to Julian Derry for help getting the full record.]

At Feb. 15th., Dr. T. G. Richardson read an elaborate paper by Dr. George Patic, of Galt, Canada West, upon the Functions of the Spinal Cord, as illustrated by experiments on cold-blooded animals;* endeavouring to show occasion for some modification of the theory of reflex action of Marshall Hall, and for the opinion that perception is one of the attributes of the spinal cord, and especially of the medulla oblongata." (p. 676)

This already sets the stage as a discussion about the question, whether the spinal cord and especially the brain stem are mere autopilots or whether some kind of perception or consciousness can be attributed to them. The Marshall Hall mentioned is associated with the theory of the reflex arc that proposed an automatic reflex involving the spinal marrow only. Hence the contex of the deliberations of the society, here, is neurobiology. (The reference given for the asterisk says: "* See N. Amer. Medico-Chirurg. Review, May, 1858." This was a common practive, to first read a paper, then publish it, so that the members of the society would know in advance, in which issue it would end up and could cite it in advance, ht to Julian Derry.) Anyway, Dr. Leidy was not convinced and argued for the autopilot. This has been reported thus:

"Dr. Leidy remarked that the experiments narrated in the paper did not appear to him entirely conclusive, as the movements described might be automatic. [...] He believed that the conveyance of impressions, in insects, for instance, to the chain of ventral ganglion, should be expected, without supposing perception to produce the apparently voluntary movements."

Leidy even recounts an experiment of his, in which he kept a pigeon alive after removing the cerebrum (that's the big part of the brain with which we consciously think) and how the pigeon would, for warmth, walk into a fire and how he needed to repeatedly pick it out of the ash-pan, or else it would have grilled itself. Thereafter, a lively debate commenced—all neurophysiology.

Compare this with Matthew (1831, p 385f) struggling to unite his idea of natural selection (circumstance-adaptive law as he called it) with the Lamarckian idea of volition and sensation having an effect on evolution:

"This circumstance-adaptive law, operating upon the slight but continued natural disposition to sport in the progeny (seedling variety), does not preclude the supposed influence which volition or sensation may have over the configuration of the body. [...opaque passage omitted...]"

He then seems to say that instinctive behaviour is more likely to be found in insects with shorter life-cycles than in animals with longer ones. For some reason he then calls this lack of continuity of individuals greater continuity of existence and concludes:

"This greater continuity of existence, or rather continuity of perceptions and impressions, in insects, is highly probable [...opaque passage omitted...]."

The whole passage is very opaque and difficult to understand. Mike Weale, for example, thinks Matthew is hinting at racial memory (he does talk about human races in one of the passages I omitted) and swarm intelligence.

In conclusion, this is a case of shoddy referencing on Sutton's part, because the author reporting the Transactions is not Leidy, as he makes his readers believe, but Hartshorne. Leidy may never have used the phrase "impressions, in insects." Moreover, the contexts are neurobiology vs. a trial at uniting Lamarckism with natural selection (circumstance-adaptive law) that is really opaque (may include stuff about swarm intelligence or racial memory).

The question is: Why should the fact that Hartshorne, in reporting the deliberations of the members of his medical society during a session on neurophysiology, used the phrase "impressions, in insects," signify that he has read Matthew (1831) having previously used the same phrase in a different context? While both contexts are science, and this case is not as devastating as the Floy–spiritualism case or the anonymous[31]–theatre-critique case, Sutton's credibility is all gone, as far as I am concerned.

Thursday, 11 February 2016

Genuinely new ideas in ecology and evolution

Dynamic Ecology had a guest post about novelty recently and the comments air the opinion that there's truly nothing new under the sun. For some reason my comments no longer get through there, so here are some examples of ideas that were genuinely new when first published:

1. Autumn lef colours are warning signals to herbivorous insects. (Hamilton and Brown 2001.

Tuesday, 20 October 2015

An ancient lore and a modern error transmogrified into the spinach-iron myth

[Click here to get all posts in this series.]
[31.032016: updated on lore dating back to the 16th century.]

The old narrative:
A misplaced decimal point caused the false reputation of spinach for being the vegetable that was richest in iron. Though still highly popular, this narrative is most likely wrong (see here). The decimal error probably never occurred in that stupidly simple way. Ignoring wrinkles in the narrative, such as that spinach is still rather rich in iron but that it cannot be assimilated well for other reasons, the new narrative can be stated most simply as follows.

The new narrative:
The decimal error is a myth, it never occurred. The false reputation of spinach was due to unreliable methods or poor experimentation. That is, errors were inherent in experimental methods, not data handling (see here).

The complex history
The narrative coming closest to the true history of this issue is probably this: An old lore about the goodness of spinach dates from times long before any of the research implicated in the myth about the decimal point error. And this folklore tenaciously maintains itself, despite repeated refutations by researchers.

In parallel to this tenacious folklore, there's a narrative about research being error prone but also self-correcting. For example, Bunge (1892) did not correct the iron contents of ash analyses for oxygen gained during combustion (see here), but he nevertheless concluded that spinach (and strawberries for that matter) do not have the high values given by Wolff (1871). That is, he drew a basically correct conclusion despite erroneous data treatment. Again, Haensel's (1909) iron contents were an order of magnitude too high for all the vegetables he analysed, but the relation between the data showed that spinach was not exceptional in comparison with the other vegetables. Haensel drew a correct conclusion based on poor data (see here). And so on in the 1930s etc.

Most of this research was not centrally or exclusively concerned with the iron content or spinach. The ash analyses of Wolff, for example, were basic/applied research in biochemistry, while Bunge was interested in finding out how baby mammals got over the suckling period depending on milk that is devoid of iron. The answer to this research question is, they get born with a store of iron that carries them through till weaning.

The myth about spinach's iron richness has been refuted along the way in the late 1800s, the early 1900s, and the 1930s, long before the legend about the misplaced decimal error has ever been aired. But the lore did not go away. Finally, Arnold Bender threw up his hands in despair and suggested that the belief may even be due to a misplaced decimal point. Now we have two legends, the iron richness and the decimal error. Both seem to be highly resilient.

The ancient lore
Once upon a time, when the Linnean system of identifying species was not even standard, Johann Ernst Zeiher (1756, vol. 2, pp. 374-375) wrote about the medical uses of spinach.

The title of the book already indicates that Zeiher translated a work from French into German, but I found no indication of the original. "Vollständiger Unterricht von Küchengewächsen: oder ausführliche Beschreibung aller Küchengewächse [...] Ferner, ihrer Nutzbarkeit für das menschliche Leben, und ihrer Tugenden, zur Erhaltung der Gesundheit, [...] u.s.w. [...] aus dem Französischen übersetzt von D. Johann Ernst Zeiher, ernenneten Professor bey der Kaiserl. Akademie der Wissenschaften zu St. Petersburg [...]". Some online search, however, shows that it must be a translation of: M. de Combles (1752) L'école du jardin potagere, [...] Paris: Chez Boudet ou Le Prieur.

For the French original see: de Combles (1752, vol. 2, pp. 24-25), for a German translation see:  Zeiher (1756, p. 374f). My own translation of it into English follows:
"The qualities of spinach in the medical arts are, to open the body/belly [whatever that means], to relieve the cough and the acerbity/acuteness of the chest: the water distilled from its leaves also has the power to attenuate the heat of the gut/bowel [sic, he uses it in singular], and the burning of a stomach irritated by an inflamed bile. One also uses the leafs for decoctions and emollient compresses. The short-winded [literal translation: tight chested] get great relief therefrom, and sometimes they were completely cured through repeated use of spinach boiled with veal: and this was the only remedy used by Mr. [Guy-Crescent] Fagon, first personal physician of Ludwig XIV, who was heavily burdened by this disease. When applied externally to the belly and the liver, it takes their inflammation and pain away. According to the opinion of a recent writer, the overuse of this plant leads to melancholy bloods: from my point of view, Mr Fagon's experience alone suffices to overthrow this opinion." 
The 18th century seems to have known a lot of lore about the medical powers of spinach, even connected to the Sun King. However, Combles (1752) also accounted for the health effects of shalotte coming before spinach and tarragon coming after. He probably discussed the health effects of each plant he treated.

Robert Hooper (1811. "Quincy's Lexicon Medicum. A new medical dictionary") corroborates that Combles' account of health effects of spinach was widespread:
"This plant Spinacea oleracea of Linnaeus is sometimes directed for medical purposes in the cure of phthisical complaints; made into a poultice, by boiling the leaves and adding some oil, it forms an excellent emollient. As an article of food it may be considered as similar to cabbage and other oleraceous plants." (Hooper 1811, p. 759
Phthisis is a dated term for suffering from consumption (tuberculosis) or other emaciating diseases. 12 years later, Achille Richard (1823, "Botanique médicale ou histoire naturelle et médicale [...]", p. 171) wrote:
"L'épinard est cultivé dans tous les jardins.Il fleurit en mai et juin. Il est peu usité comme médicament, si ce n'est à L'extérieur; on L'emploie en cataplames, et il est très émollient. Mais, comme aliment, son usage est trés-repandu. Il parait être légèrement laxatif; il est peu nourrissant et presque insipide." (For a German translation see p. 266 here)
"Spinach is grown in any garden. It blooms in May and June. It is rarely used as a drug, and if so then only externally; it is used in poultices, and it is very emollient. But as food its use is widespread. It appears to be slightly laxative; it is not nourishing and almost tasteless." (My translation)
The trend, however, seems to downgrade the medical utility of spinach from the account of Combles (1752), giving it as the only remedy for Luis XIV, to Hooper (before 1822), saying it was sometimes used, and Richard (1823), stating it was little used and if so, then only externally.

These accounts are from a time before Robert Koch described the pathogen causing tuberculosis in 1882. Phthisis and Combles' account on cough and short-windedness reminds me of the much later research of Kobert (1914) on the health effects of saponins in spinach against tuberculosis and other lung diseases (see here). That is, early research applying "modern" methods of science (e.g., chemical analyses) naturally derived its hypotheses from earlier experiences described by physicians. One such research endeavour formulated hypotheses associating spinach components (saponins) with effects against tuberculosis.

But how did the ancient lore transmogrify into a myth about the iron richness of spinach? One symptom of tuberculosis is anaemia, a lack of red blood cells or hemoglobin. Tuberculosis, however, is not the only possible cause of anaemia. Another cause is iron deficiency. Hence, other researchers could have taken the same lore documented by Combles (1752) and derived another hypothesis from it associating spinach with iron richness.

An early documentation of this spinach-iron connection can be found in a German encyclopaedia published by F. A. Brockhaus in 1852 (see P.P.S. to this blog entry). As Brockhaus only collected then-current knowledge, the idea must be older still.

The modern error
Throughout this series of reconstructing the data handling of the primary research literature, I maintained that the relevant research was full of data handling errors, but none of these errors was as simple as misplacing a decimal separator (see here).

Surprisingly, I now stand corrected on this claim. A simple decimal-point error did occur in an article published in—wait for it—Science 90, no. 2347, pp. 596-597 (1939). But the research reported there was about the iron content of dried peas and beans instead of spinach.* So how can it be the mythical error recurring in the urban legend about spinach & iron?

[* The full reference is: Aschman, Leah, Mary Speirs & Dorothy Maddox (1939) The availability of iron in dried peas and beans. Science 90, 596-597.]

Let's first take a look at the error itself. Aschman et al. (1939) report the results of an experiment that was pretty similar to the much older experiments by Bunge (1892), for example. They rendered baby rats anaemic by feeding them on milk only (mammalian milk is poor in iron). Then they fed the anaemic rats dried peas and beans, did the proper controls and measured the recovery of the rats. Along the way, they also measured the iron content of the dried products and gave the values as follows:

Anybody with a sharp eye will spot the decimal-point error in the value given for butter beans at the end. And that is what the staff of the Nutrient Section of the Bureau of Home Economics did, when they published abstracts in the Journal of Home Economics 32, no. 7, p. 481:
As you can see, however, this correction of a decimal point error concerning the iron content of butter beans follows directly on an abstract concerning the contents of oxalic acid in vegetables including spinach. Now, one big topic in the debate about the usefulness or uselessness of spinach as a dietary source of iron was oxalic acid, because it binds the iron and thus inhibits the absorption of it by the consumer.

This is probably the ultimate source of the urban legend that spinach got its false reputation for iron-richness through a misplaced decimal point. This particular source of a decimal point error could even explain why Bender (1977. The Spectator. 18 July, p. 18), the researcher who first started to spread that urban legend about spinach, iron and decimal points, associated the real but innocuous decimal point error of Aschman et al. (1939) with the name Schupan [sic] in his memory. Werner Schuphan has indeed published on the content of oxalic acid in spinach (see here).

Friday, 28 August 2015

The very first source for the legend of spinach's iron richness

For an introduction to the whole problem of the spinach-iron myth and its many ramifications read the last 7 posts of this blog (chronology: oldest post deals with oldest literature) and follow the links given in them. Beware, this myth is a mess concocted in over 160 years. What has never been discovered is the first source for spreading the opinion, during the second half of the 19th century, that spinach was a good source for dietary iron.

As you can see from my comments under this earlier blog entry, the data of Thomas Richardson (1848. Beiträge zur chemischen Kenntnis der Vegetabilien. Annalen der Chemie und Pharmacie LXVII Bd. 3.)* may well be this first source that has caused this widespread opinion. Soon after 1848 Educational publications from shortly after 1848 spread the belief that spinach was rich in iron and good for anemic people. For example, an encyclopaedia published by Brockhaus (1852. Die Gegenwart. Eine encyklopädische Darstellung der neuesten Zeitgeschichte für alle Stände. Siebenter Band. Leipzig: F. A. Brockhaus) stated at page 172: "Weiße Rüben enthalten nur eine geringe Menge von Eisen, Spinat dagegen viel." [White turnips contain only a little iron, spinach however a lot.] One year later, Aaron Bernstein published a popularisation of scientific findings in a work called "Aus dem Reiche der Naturwissenschaft: ein Buch für Jedermann aus dem Volke" (Berlin: Franz Duncker, 1853). At pages 157-158, Bernstein praised spinach as an iron rich and organic alternative to medicine for pale children. The patriarchic Hermann Klencke (1867. Chemisches Koch- und Wirtschaftsbuch oder die Naturwissenschaft im weiblichen Berufe. Leipzig: Eduard Kummer. p. 49) lists spinach among the food that is good for the breath and hematosis.

*[this publication hangs in a digital limbo, because it has been attached to the end of the preceding article by C. List (1848. Ueber das sogenannte Terpentinölhydrat. Justus Liebigs Annalen der Chemie 67(3): 362-376.]

Richardson gave the values of various chemical compounds of various vegetables as percent values in relation to the raw ash and as percent values in relation to the pure ash (raw ash minus carbonic acid, charcoal and sand). The iron content, in particular, was given as the percent values of "Phosphorsaures Eisenoxyd," which literally translates as phosphor-acidic iron oxide but chemically means iron(III) phosphate (FePO4). Richardson's data sheet also provides the percent values of the ashes in relation to the fresh matter.

As I have argued elsewhere, it is false to calculate the portion of, say, the iron compound in the fresh matter by simply multiplying the portion of the iron compound in relation to the ash with the portion of ash in relation to the fresh matter. This leads to false values, because the ashes gain mass during combustion. Gaseous oxygen binds to the burning matter, and some products of combustion end up gaseous themselves (e.g. carbon dioxide), while others end up as solid ash (e.g. magnesium oxide). That is, the ashes gain matter through combustion that is not part of the fresh matter.

It is not anachronistic to call the above mentioned calculation a mistake in relation to Richardson's time, because Phlogiston theory had been questioned in the second half of the 18th century already, and experiments had  shown that metals gain mass during combustion. Hence Richardson's contemporaries and followers should have known that simply multiplying the portion of iron compound in ash times the portion of ash in fresh matter would yield false values for the portion of iron compound in the fresh matter.

Nevertheless, Bunge (1892) failed to correct the ash values accordingly in manipulating data from Wolff (1871) as shown here. Therefore, it seems likely that others have also simply multiplied the percent values of Richardson's data and drawn false conclusions. Or, anyway, it is interesting to reconstruct what conclusions might have been drawn from such a data manipulation.

As you can see from the table below, spinach comes out second after radish herbage. Assuming that the herbage of radish was usually not eaten, however, spinach would be the edible item with the highest iron content in Richardson's data set. Hence Richardson (1848) may well be the first source from which the widespread opinion sprang that spinach was a good source for dietary iron in turn.

Item portion of iron phosphate in raw ash times portion of ash in fresh matter portion of iron phosphate in pure ash times portion of ash in fresh mater
Ananas, ganze Frucht   

ditto Schopf   

Spargel                               1,25E-04 1,60E-05
Lauch, Zwiebel                        5,52E-04 6,11E-04
ditto Stengel                         6,76E-04 8,91E-04
Feige, ganze Frucht   

Walnuts, Kern   

ditto Schale

Gurke                                 1,19E-04 1,30E-04
Brocoli (Kohl), Herz                  2,02E-04 2,14E-04
ditto Blätter                        9,86E-04 1,06E-03
Blumenkohl, Herz                      2,80E-04 2,61E-04
Rettig, Wurzel                       1,20E-03 1,41E-03
ditto Kraut                          3,20E-03 4,54E-03
Kastanie, ganze Frucht                1,77E-04 1,93E-04
Erdbeere, ganze Frucht                3,69E-04 4,56E-04
Orange ditto   

Rhabarber, Stengel                    1,66E-04 1,91E-04
ditto Blätter                         2,62E-04 2,87E-04
Spinat                               1,28E-03 1,76E-03
(Kidney Beans) Bohnen                 3,09E-04 3,56E-04
Erbsen, Hülsen                        6,90E-05 8,00E-05
Pflaumen (greengages), ganze Frucht   1,80E-04 2,42E-04
Orleans-Pflaumen, Haut der Frucht     5,39E-04 6,63E-04
Orleans-Pflaumen, Fleisch derselben   9,50E-05 1,49E-04
Orleans-Pflaumen, Kern                5,76E-04 6,28E-04
ditto Samenschale                     9,40E-05 1,05E-04
Kirschen, ganze Frucht                1,47E-04 1,61E-04
ditto Stiel derselben                 4,74E-04 5,57E-04
Birne, ganze Frucht                   6,60E-05 8,00E-05
Apfel, ditto                          5,90E-05 7,20E-05
Artischoke                            4,86E-04 5,55E-04
Lattich                               Spur Spur
Endivie                               6,72E-04 8,71E-04
Stachelbeere                          2,94E-04 3,37E-04
Sellerie                              2,56E-04 2,85E-04
Möhre                                 2,46E-04 2,39E-04
Pastinak                              4,63E-04 5,53E-04
Values in scientific notation: 1,76E-03 means 1.76*10-3 or 0.00176. This portion would be equal to 176 milligram in 100 gram fresh matter.

P.S: The Genealogical World of Phylogenetic Networks has a new post with a phylonetwork illustrating the whole dataset of Richardson (1848).

Thursday, 6 August 2015

Sources of the spinach-iron myth: Schup(h)an's true name

[Click here to get all posts in this series.]

The old narrative:
A misplaced decimal point caused the false reputation of spinach for being the vegetable that was richest in iron. Though still highly popular, this narrative is most likely wrong (see here). The decimal error probably never occurred in that stupidly simple way. Ignoring wrinkles in the narrative, such as that spinach is still rather rich in iron but that it cannot be assimilated well for other reasons, the new narrative can be stated most simply as follows.

The new narrative:
The decimal error is a myth, it never occurred. The false reputation of spinach was due to unreliable methods or poor experimentation. That is, errors were inherent in experiments not data treatments (see here). 

The complex history
Still, not everything about the spinach-iron legend is clear yet. In particular, nobody has yet thoroughly reconstructed where the original data came from, how they have been treated (mathematically) by the various researchers who wanted to reach comparability with their own data, and whether any mistakes were made in these data treatments. At the end of this series of reconstructing data handling, you will see that the whole research endeavour was full of data handling errors, though none as simple as a misplaced decimal point.

Bender's false lead
One of the unsolved riddles in the thicket of myths around spinach is the source of the decimal-point-error myth. While the urban legend is very widespread, the source of this legend remains elusive. A.E. Bender has said as much in his inaugural lecture in 1972 (see here). He later released the decimal-point-error legend upon a wider public through a letter to The Spectator.
"Sir: In a recent article (18 June) spinach is given undeserved nutritional eminence, although, since the facts have never been widely publicised, the author can be excused.
     For a hundred years or more spinach has been (and clearly still is) renowned for its high content of iron compared with that of other vegetables, but to the joy of those who dislike the stuff this is quite untrue. In 1870 Dr E. von Wolff published the analyses of a number of foods, including spinach which was shown to be exceptionally rich in iron. The figures were repeated in succeeding generations of textbooks—after all one does not always verify the findings of others including the 'Handbook of Food Sciences' (Handbuch der Ernährungslehre) by von Noorden and Saloman in 1920.
      In 1937 Professor Schupan eventually repeated the analysis of spinach and found that it contained no more iron than did any other leafy vegetable, only one-tenth of the amount previously reported. The fame of spinach appears to have been based on a misplaced decimal point."
     Professor Arnold Bender, The Spectator (18 July 1977, p. 18)

Who was Schupan?
However, neither the decimal-point error could ever be verified (see here) nor some researcher with the name Schupan be found, who published on spinach and iron during that time.

I was able to trace "Werner Schuphan" instead (mind the h after the p). While he did publish on all sorts of vegetables including spinach, the following publication from 1940 shows that he can hardly have debunked the myth of spinach's exceptional iron richness in 1937: 
"Spinat zeichnet sich – wie wir sehenbesonders durch hohe Gehalte an Carotin, Chlorophyll, Eisen und Reineiweiß und Vitamin C aus." [Schuphan, W. 1940. Über den Einfluss der Chlorid- und Sulfatdüngung auf Ertrag, Marktgängigkeit und biologischen Wert verschiedener Gemüse unter Berücksichtigung edaphischer und klimatischer Faktoren. Bodenkunde und Pflanzenernährung 19(5-6): 265-315]
"Spinach distinguishes itself – as we see – especially through high contents of carotin, chlorophyll, iron and pure protein and vitamin c." [my translation]
As the above quote reiterates the idea that spinach is richer in iron than other vegetables, it is unlikely that he had some years before claimed the opposite.

Schuphan 1937
One article published by Schuphan in 1937 [Untersuchungen über wichtige Qualitätsfehler des Knollenseleries bei gleichzeitiger Berücksichtigung der Veränderung wertgebender Stoffgruppen durch die Düngung. Bodenkunde und Pflanzenernährung 2, issue 5-6, pp. 255-304] dealt with quality issues in celeriac including the so-called Eisenfleckigkeit (iron blotchiness) of tubers. He therein debunked the belief that celery tubers turn brown at the cut surface, because of the oxidation of iron and claims that the colouring is due to resins and essential oils instead.

Another article from Schuphan in 1937 [Der gegenwärtige Qualitätsbegriff bei Gemüsen und die Notwendigkeit seiner Erweiterung auf chemisch erfaßbare Wertmerkmale. Der Forschungsdienst 3: 290-303] discussed the general discrepancy between criteria for the marketability of vegetables (e.g., size, form, colour, solidity) and nutrient quality (e.g., contents in essential oils, proteins, sugar, vitamin c). Most of his examples are taken from his own and others' research on celery. He mentions aside, the effect of P-manure on contents of vitamin c, phosphoric acid and lezithin in spinach, but iron is no issue at all.

That is, Bender's citation of a publication by Schupan in 1937 is probably wrong.

Schuphan and spinach
However, Schuphan is an interesting figure in the spinach legend for other reasons. Firstly, several of his publications suggest that spinach is rich in provitamin A, which makes him a potential source for Popeye's eating spinach for vitamin A (see here). Secondly, he published a study intended to show that the content of oxalic acid in spinach is unproblematic in 1958 (Schuphan and Weinmann: "Der Oxalsäuregehalt des Spinats." Qualitas Plantarum 5(1): 1-22). Thirdly, in 1965 he discovered that high incidences of methemoglobinaemia in babies around Hamburg, Kiel and Berlin was probably due to over-manuring spinach with nitrogen-fertilizer. A subsequent accumulation of nitrite from nitrate due either to false storage, processing or re-heating the prepared food lead to the poisoning, he suggested.*

These publications can at least suggest how the name Schup(h)an, research on spinach compounds, and the debunking of a legend about iron (though in celery) got associated in the mind of Arnold E. Bender.

* Now, I remember vividly how my parents and grandparents would always claim that the spinach mush must be eaten all up, for it cannot be re-heated. Parents always find creative was to turn scientific findings into the claim that the spinach must be eaten, it seems.

Wednesday, 5 August 2015

Sources of the spinach-iron myth: König (1926) woozily

[Click here to get all posts in this series.]

The old narrative
A misplaced decimal point caused the false reputation of spinach for being the vegetable that was richest in iron. Though still highly popular, this narrative is most likely wrong (see here). The decimal error probably never occurred in that stupidly simple way. Ignoring wrinkles in the narrative, such as that spinach is still rather rich in iron but that it cannot be assimilated well for other reasons, the new narrative can be stated most simply as follows.

The new narrative
The decimal error is a myth, it never occurred. The false reputation of spinach was due to unreliable methods or poor experimentation. That is, errors were inherent in experiments not data treatments (see here). 

The complex history
Still, not everything about the spinach-iron legend is clear yet. In particular, nobody has yet thoroughly reconstructed where the original data came from, how they have been treated (mathematically) by the various researchers who wanted to reach comparability with their own data, and whether any mistakes were made in these data treatments. At the end of this series of reconstructing data handling, you will see that the whole research endeavour was full of data handling errors, though none as simple as a misplaced decimal point.

König 1904
J. König (1904. "Chemie der menschlichen Nahrungs- und Genussmittel." Vol 2, p. 353) gives the range of iron contents in spinach as 32.7 to 39.1mg per 100g dry mass (see table below). The text above the table says that these values are from Bunge and Häusermann.

And indeed, Bunge found 0.0327g in 100g dry mass (see here), which is the same as 32.7mg in 100g. The other value of 39.1mg/100g is from Emil Häusermann (1897. "Die Assimilation des Eisens." Zeitschrift für Physiologische Chemie 23: 555-592). Like Bunge, Häusermann's main aim was to induce and study the anemia in animals, but he lists the iron contents of vegetables at the end of his publication. The value for spinach can be found at page 588 and it is taken, in turn, from Boussingault (1872. "Du fer contenu dans le sang et dans les alimants." Comptes Rendus de l'Académie des Sciences 74: 1353-9), or rather from Bunge (1892), who had taken Boussingault's data and transformed it according to König (1889, see footnote: **** here). 

Later, J. König (1926 "Nahrung und Ernährung des Menschen. Kurzes Lehrbuch. Berlin: Julius Springer, p. 31) tried to combine these values with those of a later publication by Haensel (1909. "Über den Eisen- und Phosphorgehalt unserer Vegetabilien." Biochem. Zeitschrift 16: 9-19) it seems. Haensel compared his data for various vegetables and concluded correctly, that spinach was not the richest in iron, despite the fact that his particular value for iron in spinach was roughly ten times higher than Bunge's (see here). König seems to have grappled with this inconsistency in the research record as follows:
"Eine besondere Bedeutung wird auch dem Eisen in der Nahrung zur Bildung des Hamoglobins zugeschrieben. Von dem durchschnittlichen Eisengehalt des erwachsenen Körpers von 3g sollen etwa 1/6 auf Hamoglobin entfallen. Hiervon werden täglich 80-100 mg in Freiheit gesetzt. Diese werden von Leber, Milz und sonstigen Drüsen größtenteils gespeichert, so daß der tägliche Bedarf in der Nahrung nur 20-30mg betragen solI. Solche Mengen Eisen sind auch wohl in einer gemischten Nahrung vorhanden. Die größten Mengen Eisen finden sich in grünen Gemüsen, nämlich in 100g 30-60mg Fe203 (die Höchstmenge im Spinat); andere Nahrungsmittel enthalten nur den 10. Teil und noch weniger." König (1926, p. 31)
"Special significance for forming the hemoglobin is attributed to the iron in the diet. About 1/6 of the average 3g iron in an adult body if in the hemoglobin. Of these, 80-100mg are liberated daily. These are mostly stored in the liver, spleen and other glands so that the daily requirement in dietary iron amounts to 20-30 mg. Such amounts of iron are also well available in a mixed diet. The largest amounts of iron can be found in green vegetables, namely in 100g 30-60mg Fe203 (the maximum quantity in spinach); other foods contain only the 10th part of this and even fewer." (my translation)
At page 82 König cites Haensel (1909) and another, but not on spinach. My translation below is not garbled, the original is:
"Unter den Mineralstoffen wird auch dem Eisen der grünen Gemüse wegen der blutbildenden Eigenschaft eine besondere Bedeutung zugeschrieben. R. Berg fand in 100g frischem Gemüse Spuren (Wirsing) bis 150 mg Eisen (Bleichsellerie); E. Haensel 3,9 mg (Zwiebel) bis 68,9 mg Eisen (Kohlrabiblätter) oder 31-37,9 mg Eisen in 100 g Trockensubstanz."
"Among the minerals a special importance is also attributed to iron of the green vegetable because of the blood-forming capacity. R. Berg found in 100g fresh vegetables tracks (Savoy) up to 150mg iron (celery); E. Haensel 3.9mg (onion) to 68.9mg iron (Kohlrabi leaves) or from 31 to 37.9mg of iron in 100 g of dry matter."

Coming full circle, page 86 correctly states that spinach contains no more iron than other green vegetables and refers back to page 82, where, as we have seen, nothing is said about spinach.