Thursday, September 14, 2006

Wikipedia, Phlogiston, and Tradition

When looking at the Wikipedia link about the Phlogiston theory, a couple of things stand out. First, and I think that this is just becuase becuase I am the sort of person who reads the end of a story first, the bibliography only contains one reference, and it is from 1900.

1900? Since it is not a primary source, I find it a little circumspect. Couldn't the author have found the information from a more current source? It is not that I believe that the content of the article is isn''s just that really old sources like that cannot be connected to the current literature in a significant way.

The next thing that stands out about the article, to me, is the way that the description of the theory removes it from its historic context. It is one thing to explain who developed the theory and what it stated. I think that that would be in traditional encyclopaedia form. This article in fact tried to elaborate on the history of the theory by describing its "enduring aspects":

'Phlogiston theory allowed chemists to bring explanation of apparently different phenomena into a coherent structure: combustion, metabolism, and formation of rust. The recognition of the relation between combustion and metabolism was a forerunner of the recognition that the metabolism of living creatures and combustion can be understood in terms of fundamentally related chemical processes.'

This statement reeks of positivism. I have a personal dislike for arguments that try to directly connect the science of the present to what was being done in the past. Earlier I mentioned that the article removed the theory from its historic context. I'll elaborate on that now. From my own reading on the subject, what one has to consider when looking at eighteenth century theories is that people saw the world completely differently from the way that we see it. That seems pretty obvious doesn't it: they were living over two hundred years ago, right?

What the article does not explain about the Phlogiston theory is why the theory appeared when it did. Why did it not appear earlier, or later? Perhaps the latter is easier to answer, in the article the author explains that Lavoisier "discovered" oxygen, leading to the notion of oxygenation.

However, why did Becher come up with the theory when he did (by the way...the article does not give an exact date as to when the theory was developed)? That is, why did it appear then? I beleive that this is important information that the aticle negelects to bring up. Becher's theory should be understand as a philosophical theory as much as it is a "scientific" one. The notion of Phlogiston is akin to earlier notions of "life force" (soul, pneuma, chi). That is, it is an unquantifiable factor at play in everyday life. The theory was postulated as a resistence to the iatromechanism of the day.

This is why I thought that the author missed the point of the theory. It was not a precursor of modern chemistry, specifically because it was not intended to help explain physical phenomena in terms of reducible, quantifiable substances.

The wikipedia article is interesting, as a primer. However, it removes the theory from its historic context, and creates illusory links to modern chemistry.

1 comment:

Daryl & Tiang said...

I'm from Erie, PA, USA (Just across the lake) and I'm sure you and your readers would be interested in the following passage from an early 20th century writer:
By the way, I'm a highschool science teacher and I love starting out the school year by asking students what they know about phlogiston. I light a birthday candle and have three test tubes, one filled with air and two with oxygen. I let the students guess how long the candle will burn when covered with the test tube then I demonstrate. I then say that we will try again to get an average mesure. I cover the candle with a test tube full of oxygen and it burns brightly and long. Then I say, "Lets try that again." This time I don't bother lighting the candle but I put it in the oxygen filled tube and, of course, a flame magically appears on the candle. Then I tell them how phlogiston can explain all of this.

By Henry Smith Williams
The great physicists of the day being at one regarding the existence of this all-pervading ether, it would be a manifest presumption for any one standing without the pale to challenge so firmly rooted a belief. And, indeed, in any event, there seems little ground on which to base such a challenge. Yet it may not be altogether amiss to reflect that the physicist of to-day is no more certain of his ether than was his predecessor of the eighteenth century of the existence of certain alleged substances which he called phlogiston, caloric, corpuscles of light, and magnetic and electric fluids. It would be but the repetition of history should it chance that before the close of another century the ether should have taken its place along with these discarded creations of the scientific imagination of earlier generations. The philosopher of to-day feels very sure that an ether exists; but when he says there is "no doubt" of its existence he speaks incautiously, and steps beyond the bounds of demonstration. He does not KNOW that action cannot take place at a distance; he does not KNOW that empty space itself may not perform the functions which he ascribes to his space-filling ether.
Meantime, however, the ether, be it substance or be it only dream-stuff, is serving an admirable purpose in furnishing a fulcrum for modern physics.
(Early 20th century)