Monday, January 17, 2011

Taking the Piss out of Vitalism




Friedrich Wöhler (1800-1882)


The notion that matter from living beings essentially differs from matter derived from non-living sources used to be called vitalism. Vestiges still remain. Historically, the terms "organic" and "inorganic" delineated the chemistry of life from the chemistry of inanimate matter. Over time, "organic chemistry" morphed into the generic chemistry of carbon and, within that genus, biochemistry came to mean the chemistry of living things. This left "inorganic chemistry" to cover the chemistries of every other element. That is more or less the state of things today. Biologists have encroached on biochemistry with molecular biology, bringing along their cellular frame of reference.

We credit Friedrich Wöhler, a 19th century German chemist, with undoing the notion of vitalism in chemistry. He synthesized urea, which had only ever been isolated from urine. The whole story is beautifully retold here. As part of an Internet wager, I tracked down the original letter from Wöhler to his erstwhile mentor, Professor Jakob Berzelius; I partially translated it from German:
Berlin, February 22, 1828
Dear Professor!
Although I surely hope that my letter of January 22nd and the post-script from February 2nd have arrived, I live every day, or rather every hour with the anxious hope to get a letter from you. I wanted to wait to write again but I cannot, so to say, "hold my chemical water" and must say that I can make urea without the use of kidneys or even an animal, whether it be human or canine. Ammonium cyanate is urea. [1]
Wöhler went on to describe how natural urea from urine, Pisse-Harnstoff, was the same as artificial urea.  He then ended with a possible "out" for the adherents to vitalism:
This artificial formation of urea--can it be an example of forming an organic substance from inorganic materials? It is remarkable that cyanic acid (and ammonia) are originally produced from an organic substance, and a natural philosopher would say that both come from an animal carbon, and from the resulting formed cyanic compounds, the organic has not yet disappeared, and therefore an organic body is produced yet again. 
Your Wöhler.

How Wöhler took the piss out of vitalism (so to speak) is a nice example of what T. H. Huxley meant when he later wrote:
The great tragedy of science, the slaying of a beautiful hypothesis by an ugly fact.
I got into a friendly wager over on Twitter after I discovered that both Wöhler and Huxley were credited with that pithy saying.

I tweeted: Who wrote "The great tragedy of science, the slaying of a beautiful hypothesis by an ugly fact."?

"T.H. Huxley" responded StarlessTwit

Not so fast I responded: "That's what the Internets would have you believe but there is this."  The link goes to a Wiki link crediting Wöhler with the saying.

I wagered that Wöhler had said it originally and that Huxley had been miscredited: link

That's when amba, the fact checker, weighed in, citing original source: "sorry to disappoint"

I can't finding anything close to what Huxley said in the original letters between Wöhler and Berzelius.  Wiki is wrong on this count.

Never bet against amba.

_________________

[1] Wöhler treated cyanic acid, HOCN, with aqueous ammonia and generated ammonium cyanate, NH4CNO. Ammonium cyanate is unstable and spontaneously rearranges to the more stable urea in situ:

2 comments:

  1. It's amazing how much progress chemistry made in the 30-odd years between, say, Lavoisier's execution and this time of Wöhler's synthesis. 35 years earlier, Lavoisier still had to fight phlogiston, but by the late 1820's they're starting to do organic synthesis, and have at least some idea what they were doing in the bargain.

    The early 19th century was really one of those heroic periods in science. Consider what was happening with electricity. They went from static machines and Leyden jars as parlor tricks to amuse bewigged gentlemen and hoop-skirted ladies to batteries, and, ultimately, prototypes of dynamos, arc lights and electric motors all during the same time as this chemistry was developing.

    And they weren't wearing any wigs when they got through, either.

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  2. It's amazing how much progress chemistry made in the 30-odd years between, say, Lavoisier's execution and this time of Wöhler's synthesis. 35 years earlier, Lavoisier still had to fight phlogiston, but by the late 1820's they're starting to do organic synthesis, and have at least some idea what they were doing in the bargain.

    It was a rich time. Just a year earlier, in 1827, Zeisse prepared is eponynous salt by accident. K[PtCl3(C2H4)]·H2O was the first pi-complex, though it was hardly appreciated at the time. Zeisse fought the established chemists in his day and it wasn't until the 1950's that people realized exactly what it was.

    The early 19th century was really one of those heroic periods in science. Consider what was happening with electricity. They went from static machines and Leyden jars as parlor tricks to amuse bewigged gentlemen and hoop-skirted ladies to batteries, and, ultimately, prototypes of dynamos, arc lights and electric motors all during the same time as this chemistry was developing.

    I just ordered a book on Michael Faraday. He was a true hero, I think, and of course he did get the attention that he deserved, though he also had his detractors.

    Thank you for your thoughtful comment TimB!

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