Vitalism is the doctrine that processes of living organisms are governed by unique principles due to a “vital essence” that is separate and distinct from the laws of physics and chemistry. In the 19th century, many scientists accepted the idea of a vital essence as a fundamental principle.
In 1828, German chemist Friedrich Wöhler accidentally synthesized the organic molecule urea using inorganic chemicals. Organic molecules are chemical structures constructed from carbon atoms. Urea, well, that is found your urine.
Urea was first isolated from urine in 1727 by Herman Boerhaave. Urea is the predominant molecule used by our bodies to excrete nitrogen and, as such, is naturally made by living organisms.
The synthesis of urea has gone down in many textbooks as the refutation of vitalism, but no single experiment refuted vitalism entirely.
Wöhler did not carry out this experiment with the purpose of dispelling vitalism. He did not even discuss the implications that this experiment could have on vitalism in his 1828 paper. Most importantly, the vitalist community did not even take much notice of Wöhler’s experiments at the time.
The idea of vitalism carried on long after. In 1840, Wöhler’s own teacher, Jöns Jacob Berzelius, voiced his continued belief in vitalism.
In 1857, a dispute arose between chemists Louis Pasteur and Justus von Liebig regarding the nature of alcoholic fermentation. Pasteur believed the process was vitalistic in nature, while von Liebig believed the process had a chemical basis.
The von Liebig-Pasteur controversy was not settled until Eduard Buchner uncovered the cause of alcoholic fermentation in 1897.
Buchner managed to isolate an enzyme complex from yeast cells, which he named zymase, that had the ability to ferment alcohol. Enzymes are proteins with the ability to facilitate chemical reactions.The fermentation process was shown to occur in the absence of living yeast cells, disproving Pasteur’s stance.
Vitalism was ultimately snuffed out in science by a steady accumulation of experimental evidence demonstrating that key life processes follow the same rules as chemical reactions carried out in test tubes.
However, remnants of vitalism can still be seen in everyday life. One example lies in the distinction between “synthetic” and “natural,” or “organic” substances. The idea that something can be both synthetic and organic may be a source of dissonance for some, but chemists know that the properties of substances depend on their structures, not where they come from or how they are made.
Naturally-sourced substances and synthetic chemicals both arise through sequences of chemical reactions. These reactions work to build up a final molecule. Synthetic chemists often use different reactions from those used in nature, much like Wöhler did in 1828. Like Wöhler’s urea and urine’s urea, synthetically-prepared and naturally-occurring versions of the same substance are identical.
A naturally-sourced product is not inherently healthier or more effective than a synthetic one. Both types of products can contain impurities, additives, or by-products, which may or may not impact the safety of the product.
For example, some people use melatonin to address sleep disorders and treat jet lag. Whether you buy synthetic or naturally derived melatonin, what you are purchasing isN-acetyl-5-methoxytryptamine. The natural molecule is identical to the synthetic version. However, melatonin extracted from animal pineal glands may be contaminated by viruses.
University of Manitoba chemistry professor Phil Hultin tells his students, “Molecules do not know or care how they were made. Whether they are beneficial or harmful depends only on their structure and on how people use them.”
What is natural? In the scientific sense, everything is! Science concerns the exploration of our natural universe. Synthetic organic chemistry is just as natural as landing probes on far-off comets or the Pythagorean theorem.