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Return to: A Case Study of Academic Misconduct, Peer Review Failures and Journal Coverups of Published Errors



Two Views of Helmont's Willow Experiment




Hershey's May, 2002, JCST Letter

It is hard to believe a scholar would publish, and a referred journal would allow to be published, numerous obscure historical facts on Helmont without a single literature citation to support them. Yet Allchin (JCST, September 2000, pp. 33-37) did and got nearly every fact wrong. The Helmont part of Allchin (2000) was also nearly verbatim from the uncited Allchin (1993). The editor of Allchin (1993) apparently had serious reservations and took the extremely unusual step of publishing reviewers' criticisms of Allchin's manuscript. Reviewers (Anonymous 1993) urged Allchin (1993) to add citations but he refused. Allchin (2000) faulted Hershey (1991) for criticizing Helmont's 1648 willow experiment out of historical context. However, virtually every criticism Hershey (1991) made of Helmont could have been made in Helmont's era and some were.

Allchin (2000) was wrong that growing plants in water alone was inconceivable in Helmont's time. Bacon (1627) grew terrestrial plants in water as did several others of Helmont's era (Webster 1966). Allchin (2000) was wrong that Helmont had no conception of distilled water. Helmont said he used distilled water in his experiment (Krikorian and Steward 1968), and distillation as a purification method was well known in Helmont's era (Multhauf 1956).

Allchin (2000) thought criticizing Helmont for not using replication lacked historical context. However, Boyle in the 1640's (Hoff 1964) did three Helmont-type experiments before he had read Helmont's experiment (Krikorian and Steward 1968). Boyle found 0 pounds soil missing, then repeated the experiment and found 1.5 pounds missing (Hoff 1964) which revealed substantial experimental error. Woodward (1699) criticized the accuracy of Helmont's weighing and soil drying methods.

Contrary to Allchin (2000), Helmont's use of a pot and sinking the pot were not innovations. Growing trees in pots, especially oranges overwintered in caves or orangeries, was common in Helmont's time (Muijzenberg 1980). Plants had been grown in pots since ancient Egyptian times (Baker 1957). Gerard (1633) illustrated a planted pot sunk in the ground. Allchin's (2000) idea that Helmont sunk his pot to keep location constant is a guess. Hershey (1991) discussed other possible reasons for sinking the pot but no one knows the real reason. Perhaps Mrs. Helmont didn't want a huge, ugly pot sitting in the yard for five years!

Allchin (2000) wrote: "Carbon dioxide [was] a substance wholly outside his conception." However, Helmont coined the term "gas", discovered carbon dioxide and is the "real founder of pneumatic chemistry" (Leicester and Klickstein 1963). Helmont even described several sources of carbon dioxide including belches, fermenting wine and burning charcoal, which is of plant origin (Pagel 1972). Thus, Helmont knew that plant matter released carbon dioxide upon burning.

Allchin (2000) stated that it was "historically outlandish" to portray Helmont as both "hero and fool." However, in his era Helmont was regarded exactly that way because his "combination of mysticism, magic, alchemy, and new science irritated even his contemporaries" (Heinecke 1995). Even Helmont admirer, Robert Boyle had that hero-fool view because Boyle thought a mysticism-heavy treatise written by Helmont was misattributed to Helmont by his detractors (Heinecke 1995). Boyle couldn't comprehend how Helmont, who made many important scientific discoveries, could also produce such unscientific nonsense.

In Hershey (1991), I suggested "class discussion" and a weighing demonstration but teachers were free to use Hershey (1991) with any teaching strategy. They did not have to simply give it to students as Allchin (2000) complained. As in many American Biology Teacher articles, I provided mainly content, not pedagogy.

Allchin (2000) misattributed the statement "willows do not live by water alone" to me (1991). That quote was by Allchin (1993) himself.

The above comments were intentionally abbreviated at the editor's suggestion. Please email me if you wish more details.

David R. Hershey
dh321z@yahoo.com

References

Allchin, D. 2000. How not to teach historical cases in science. Journal of College Science Teaching. 30:33-37.

Allchin, D. 1993. Reassessing van Helmont, reassessing history. Bioscene 19(2):3-5.

Anonymous. 1993. Anonymous reviewers' comments on reassessing van Helmont, reassessing history. Bioscene 19(2):30.

Bacon, F. 1627. Sylva Sylvarum. London: J. Haviland.

Baker, K.F. 1957. The UC System for Growing Healthy Container-Grown Plants. (University of California Agricultural Experiment Station Manual 23). Berkeley, CA: University of California.

Gerard, J. 1633. The Herbal or General History of Plants. New York: Dover.

Heinecke, B. 1995. The mysticism and science of Johann Baptista van Helmont (1579-1644). Ambix 42(2):65-78.

Hershey, D.R. 1991. Digging deeper into Helmont's famous willow tree experiment. American Biology Teacher 53:458-460.

Hoff, H.E. 1964. Nicolaus of Cusa, van Helmont, and Boyle: The first experiment of the renaissance in quantitative biology and medicine. Journal of the History of Medicine and Allied Sciences. 19:99-117.

Krikorian, A.D. and Steward, F.C. 1968. Water and solutes in plant nutrition: With special reference to van Helmont and Nicolaus of Cusa. BioScience 18:286-292.

Leicester, H.M. and Klickstein, H.S. 1963. A Sourcebook in Chemistry 1400-1900. Cambridge, MA: Harvard University Press.

Muijzenberg, E.W.B. van den. 1980. A History of Greenhouses. Wageningen, The Netherlands: Institute for Agricultural Engineering.

Multhauf, R. 1956. The significance of distillation in Renaissance medical chemistry. Bulletin of the History of Medicine 30:329-346.

Pagel, W. 1972. Helmont, Johannes (Joan) Baptista Van Helmont. pp. 253-259, vol. 6. IN: C.C. Gillespie (ed.) Dictionary of Scientific Biography. New York: Scribner.

Webster, C, 1966. Water as the ultimate principle of nature: The background to Boyle's Sceptical Chymist. Ambix 13: 96-107.

Woodward, J. 1699. Some thoughts and experiments concerning vegetation. Philosophical Transactions of the Royal Society 21:193-227.


Allchin's response to Hershey's May, 2002, JCST Letter

Mr. Hershey, I fear, has failed to appreciate my argument in "How Not to Teach Historical Cases in Science." There, my primary focus was historical context and its importance in understanding the progress and nature of science. If you get the context wrong, even the "facts" themselves can be misinterpreted. Historical accuracy includes getting the perspective "right."

Hershey notes that we attribute the term "gas" to van Helmont. One may well be tempted to take this as showing how modern Helmont was. However, while we may recognize the word, we hardly adopt Helmont's meaning. For Helmont, a gas was the spiritual essence specific to each substance, which would be given off when it was heated or burned. Although material, a gas was embued with spirit. It was also the vital essence of the blood. It was converted from water by ferments, agents of transmutation (also responsible for digestion and spontaneous generation). But a gas was not water vapor. Nor was it air. Helmont compares gas to blas (a complementary word, that, by contrast, has receded into obscrurity), an astral power of movement akin to Hippocratic enhormon (Helmont 1664, Treatise #15, pp. 70-77; Tr. #16, pp. 78-81; Tr. #20, pp. 106-108; see also Pagel 1982). To imagine that Helmont conceived gas as we do now is historically inaccurate.

So, too, for the concept of distilled water. While Helmont surely understood the process of distillation, he could not have meant conceptually what we mean today by distilled water. For Helmont, water was an element. For Helmont's contemporaries, earth (the sediment one might remove by distillation) was another element. Distilled water was, crudely, water free of earth. One cannot import today's conceptions of mineral ions or solutes.

So, too, for carbon dioxide. Oxygen was not identified as an element until the 1770s, so whatever Helmont may have isolated - and whatever we may call it - Helmont could not have conceived it as carbon dioxide. Rather, it was the spiritual essence of coal (Helmont 1664, Tr. #20, p. 106). Air was viewed as an element for many years to come, not a mixture - and certainly not a mixture of Helmontian gases. Even a century later, Joseph Black would refer to (today's) carbon dioxide as fixed air, not a distinct compound containing carbon and oxygen as elements.

In the same way, statistical "replicates" are a far cry from repeated experiments. How can we understand Helmont's experiment in historical context if we misinterpret his very words by applying modern meanings anachronistically.

Thus, while anyone might acknowledge that Hershey has identified several interesting and relevant tidbits of history, one ought not be persuaded that he represents well Helmont's historical perspective. For those who wish to know more about Helmont and his fascinating views, I recommend Pagel's 1982 book.

On more particulars, Mr. Hershey may wish to check his historical facts before ascribing views to me or the editor of my 1993 article. I was invited to submit this article, reflecting the editor's enthusiasm, not "serious reservations." I was not given the reviewers' comments, hence did not "refuse" to heed them. As I understand the editor's comments to me, the critique was added to placate prospective readers who (perhaps like Hershey) would find my message challenging. From Hershey's focus and tone (and overstatements of my position), a reader might well wonder whether correct historical facts are all that concern him.

I invite JCST readers to read Hershey's original article and judge for themselves. I will also echo my earlier comments: Teachers must learn to use history - like any tool - appropriately. Most important, teachers should place a scientific problem in the full historical context, less they distort the very subject they hope to illuminate.

Douglas Allchin
Minnesota Center for the Philosophy of Science
University of Minnesota
Minneapolis, MN 55455
email: allchin@pclink.com.

References

Helmont, J.B. van. 1664. Works. London: Lodowick Lloyd.

Pagel, W. 1982. Joan Baptista van Helmont: Reformer of Science and Medicine. Cambridge: Cambridge University Press.


Hershey's rebuttal to Allchin's JCST letter:

First of all, it would be correct and polite if you referred to me as Dr. Hershey rather than Mr. Hershey because, as you know from our email correspondance, I have a Ph.D.

Fear not Dr. Allchin, I understand your argument in Allchin (2000) but that is not what my letter was about. The issue I raised was Allchin (2000) getting several Helmont "facts" wrong. You harp on getting the "historical context" right but by definition, historical context is just the facts for a particular event or situation. It is unfortunate that Dr. Allchin did not directly address each of those Helmont "facts" and either provide literature citations to support them or admit the "facts" were wrong. There are so many misconceptions in the biology teaching literature already, we don't need more.

Dr. Allchin can't get the historical context right with wrong facts, such as "Concerns about distilled water in the context of an experiment done centuries before anyone understood the concept of distilled water are grossly misplaced" (Allchin, 2000). Helmont's distilled water was not that different than distilled water today even if he didn't understand the chemistry of water as we do now. Allchin's letter discussed that Helmont's conception of distilled water was "water free of earth". Even with that definition, distilled water was still extremely important in Helmont's experiment because the crux of the experiment was accurately weighing the dry soil before and after plant growth. Helmont knew he had to irrigate his potted willow with "water free of earth", either distilled water or rain water, to avoid adding additional dry weight to his 200 pounds of soil. Therefore, distilled water was a concern for Helmont, which is clear from Helmont's experimental description.

I never implied that Helmont had a modern conception of distilled water in terms of ions and elements. What I did say was that for Helmont to clearly and logically test his theory that plants arose from water alone, he would have had to grow his willow in a pot of distilled water or rain water (Hershey 1991). That was perfectly logical in Helmont's time, and plant water culture was known in Helmont's time. Helmont was either unaware of the plant water culture work described by Bacon (1627) in his well known book or ignored it.

If Dr. Allchin wanted the proper historical context, then Allchin (2000) should not have said that carbon dioxide "was a substance wholly outside his conception" because Helmont did have some conception of carbon dioxide. He described many sources of carbon dioxide gas. I did not imply he had a modern conception of carbon dioxide but Helmont did describe how 62 pounds of oak charcoal yielded 1 pound of ash and 61 pounds of carbon dioxide gas (Leicester and Klickstein 1963). Based on the oak charcoal data and willow data, reasonable questions to Helmont by a contemporary would have been, Couldn't the willow dry matter be composed mainly of carbon dioxide gas plus a small percentage of ash or earth? Might not the missing two ounces of soil from the willow pot represent the ash or earth left after the willow is burned?

The context of Hershey (1991) was to provide content for high school or introductory college biology teachers. I did not feel delving into Helmont's "fascinating views" was appropriate at that level because Helmont was a very complex character and had many mystical views even his contemporaries considered unscientific. As Dr. Allchin did in his letter, I cited Pagel (1982) and other references on Helmont where teachers could find more details if they desired.

The second paragraph of Allchin's letter explaining Helmont's confusing, unscientific ideas on gases is a perfect example of why I avoided such details. Helmont's ideas on gases are mainly gross speculations with no scientific observations or data to support them. Allchin's second paragraph would totally confuse most biology teachers and their students. Even his biographer (Pagel 1972) noted that Helmont's scientific writings "are embedded in his discourses on natural philosophy, cosmology, and religious metaphysics, which are not scientific, and are difficult for the modern reader to comprehend."

I choose to deal with Helmont's very well known and straightforward willow experiment and objectively scrutinized it from the standpoint of experimental design and analysis (Hershey 1991). Focusing at all on Helmont's largely unscientific ideas on gases would have interfered with the focus on experimental design. My purpose was not to teach biography or Helmont's mystical beliefs, but to use a familiar historical experiment as a basis for a discussion of modern experimental design. Dr. Allchin seems to consider my approach improper, which I find extremely unreasonable. Helmont's experiment is part of the scientific literature so is fair game for discussion on its scientific merits. Unlike the title of Allchin (2000), I was not really teaching a "historical case in science", I was mainly critiquing an experiment from the scientific literature. Is is very important for students to learn how to objectively and intelligently critique published experiments so they can draw the proper conclusions and design excellent experiments of their own.

I don't know, and had no way of knowing, if the Bioscene editor showed Dr. Allchin the anonymous reviewers' comments before Allchin (1993) was published. Bioscene is a refereed journal and claims to follow the normal review process where a journal editor solicits two or more anonymous peer reviews and shows them to the author. If Dr. Allchin had proof that my letter was factually incorrect, he could have emailed me, and I would have gladly changed it prior to publication. Before I submitted a letter to the editor, I emailed Dr. Allchin to discuss the errors in Allchin (2000) but he was not willing to continue the discussion and forwarded my email to the Journal of College Science Teaching for publication as a letter.

I said the Bioscene editor "apparently had serious reservations" about Allchin (1993). I based that conclusion on the fact that the Bioscene editor took the highly unusual step of publishing the peer reviewers' comments (Anonymous 1993) in the same issue as Allchin (1993). If a journal editor surprised me by publishing anonymous reviewers' comments that I had never seen, I would have published a letter or article in a subsequent issue that addressed the reviewers' concerns. Dr. Allchin did not publish a response to Anonymous (1993).

I find it impossible to believe that Dr. Allchin never saw the anonymous reviewers' comments (Anonymous 1993) after they were published because they were referred to at the end of Allchin (1993). Therefore, the logical conclusion is that Dr. Allchin did "refuse to heed them" because Allchin (1993) was reprinted nearly verbatim as part of Allchin (2000). The anonymous reviewers' suggested topics and additions of literature citations were never added, and Dr. Allchin did not even cite Allchin (1993) in Allchin (2000).

I think Dr. Allchin's statement,

"From Hershey's focus and tone (and overstatements of my position), a reader might well wonder whether correct historical facts are all that concern him."

is a nasty attempt at obfuscation that is inappropriate for a discussion in a science journal. To imply that I have some motive other than to point out the faulty Helmont "facts" in Allchin (2000) is ridiculous and untrue. I have published articles (Hershey 1990, 1992, 2000, 2001) and dozens of letters pointing out factual errors in the biology teaching literature. However, unlike Allchin (2000) I provide literature citations to support my facts (Hershey 1990, 1992, 2000, 2001).

Allchin (2000) included several Helmont "facts" without citing a single source to support them, and most of the "facts" are plainly wrong because they are contradicted by the historical literature. Publishing historical "facts" without confirming their accuracy via literature citations is certainly an ironic example of "How Not to Teach Historical Cases in Science", the title of Allchin (2000). Unlike Allchin (2000), I have provided literature citations to support the rejection of Allchin's flawed "facts".

I second Allchin's call for readers to examine Hershey (1991) and judge for themselves. They can also read web versions of Allchin (2000), Allchin (1993), and Anonymous Reviewers' Comments on Allchin (1993)

David R. Hershey, Ph.D.
dh321z@yahoo.com

References

Allchin, D. 1993. Reassessing van Helmont, reassessing history. Bioscene 19(2):3-5.

Allchin, D. 2000. How not to teach historical cases in science. Journal of College Science Teaching. 30:33-37.

Anonymous. 1993. Anonymous reviewers' comments on reassessing van Helmont, reassessing history. Bioscene 19(2):30.

Bacon, F. 1627. Sylva Sylvarum. London: J. Haviland.

Hershey, D.R. 1990. Vintage plant science textbook data need updating. Journal of Agronomic Education 19:198-199.

Hershey, D.R. 1991. Digging deeper into Helmont's famous willow tree experiment. American Biology Teacher 53:458-460.

Hershey, D.R. 1992. Is hydrotropism all wet? Science Activities 29(2):20-24.

Hershey, D.R. 2000. The truth behind some great plant stories. American Biology Teacher 62:408-413.

Hershey, D.R. 2001. Knop's solution is not what it seems. Science Activities 38(3):17-20.

Leicester, H.M. and Klickstein, H.S. 1963. A Sourcebook in Chemistry 1400-1900. Cambridge, MA: Harvard University Press.

Pagel, W. 1972. Helmont, Johannes (Joan) Baptista Van Helmont. pp. 253-259, vol. 6. IN: C.C. Gillespie (ed.) Dictionary of Scientific Biography. New York: Scribner.

Pagel, W. 1982. Joan Baptista van Helmont: Reformer of Science and Medicine. Cambridge: Cambridge University Press.




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