The Birth of the Micro Organism

The infamous scientific battle between Pasteur and Pouchet resulted in the advancement of an understanding as to how microorganisms originate. In addition to advancing this important field for science and medicine, the debate was notable because it ultimately improved the way in which scientific experiments were conducted at large and provided a new context for scientific scrutiny; Pasteur's experiments paved the way to sterilization in experiments. It also changed the idea of spontaneous generation which was a deeply ingrained belief not only held by scientists at the time, but which was also seen to support the theory of evolution. This had certain political repercussions which will be discussed as the debate was not only about science and the experimental method, but also one that was fueled by religion and politics. This debate led to a revolution for science, and also illustrated a contention between faith and the scientific institution. The debate not only changed the scientific landscape, but also illustrates a triumph of science over superstition and myth. Ultimately, while this debate was surrounded by many outside influential factors which tainted its integrity in some ways, one can see how science is inseparable from such political, personal and social influence. We need to acknowledge this if we want to find a realistic scientific model and understanding of what science is.

The basis of the debate was as follows. Pouchet stated that life was simply the result of ambient matter in the environment. This means that the origins of life require no parent and are simply made up of a re-assembly of the matter in the environment. Pouchet stated that, for example, eggs are required to create animals, but that the eggs themselves are created from the environment around them. This is what he refereed to as, “Force plastique”. It insinuated that there was some sort of force or spiritual nature involved in the creation of life.

"The succession of life on the surface of the globe links matter in a narrow circle from which it cannot escape. It is successively attracted and repelled by these incessant phenomena. But the organic particles, sometimes intimately united to form organisms, and sometimes free in space, are no less animated with a latent life, which seems to wait only for their grouping to be visibly manifested. It seems that for organic molecules, there is no death ... only a transition to a new life." (Farley, 1998)

However, many believed that this spontaneous generation was a threat to the church, because it required the random combination of molecules, and thus could also be seen to support evolution. This is one more reason, beyond the basic interests of science, that Pouchet was so heavily scrutinized by Pasteur and the Academy of Sciences. (Farley, 1982)

The debate was fueled by to two notable experiments. First Pouchet, who was also the Director of the Natural History Museum in Rouen, made the following mission statement, which was in support of what he called 'heterogenesis'; a more scientific euphemism for 'spontaneous generation'.

“When I had thought about the matter long enough to become convinced that spontaneous generation is still one of the means that nature uses to reproduce its creatures, I set out to discover which procedures would allow us to bring these phenomena to light.” (Barnett, B., 2011)

He believed that spontaneous generation was thus a natural scientific process, and that it entailed the generation of living material from previous living plants and animals. He performed a series of experiments which resulted in his most famous one, which ultimately sparked the real controversy. He set out to prove that microbes could grow even in the absence of atmospheric air. In this he was attempting to prove that the growth of microbes was independent of contamination from the environment, and thus spontaneous generation was the actual source of life.

He filled a flask with boiling water and hermetically sealed it. He then put it into a mercury trough which rapidly cooled the substance. Then he put in artificial oxygen and calcified hay, which was known to encourage the growth of a certain fungus. The fungus did indeed grow and thus he claimed that microbes are capable of growing in the absence of atmospheric contamination; this was supposed to prove that spontaneous generation was possible.

Many scientists were quieted and puzzled by the experiment, and the greatest issue was that they could not actually prove Pouchet wrong. However, he had many critics and in 1882 the Academy of sciences proposed a new topic for the Allhumbert prize in natural science,

“To attempt by means of well-designed experiments to cast new light on the question of so-called spontaneous generations.” (Barnett, B., 2011)

The committee was comprised of of Milne-Edwards, Flourens, Brongniart, Serres, and Geoffroy Saint-Hilaire. They were open critics of Pouchet's work and set out to systematically destroy his argument. You can imagine what a stage for controversy this caused; The Academy of sciences actually created a committee and a prize in science to challenge Pouchet's findings (which he was deeply committed to). This was not only a scientific debate, but also a personal attack aimed at Pouchet. The debate which ensued also illustrated the fact that debate in science is difficult to remove from something personal in nature for the scientists involved. Also, because of its religious implications in relation to Darwinism, it was of religious and political importance. Pouchet had negated the usual sources of contamination in his experiment by heating the hay to 300 degrees, boiling the water and using an artificial source of oxygen. However, Pasteur was obviously not convinced and made the following claim, which we can also imagine was quite blow to Pouchet's ego:

“I shall demonstrate that there was one source of error that M. Pouchet did not notice, that never occurred to him, that had never occurred to anyone before him, and that this source of error makes his experiment completely useless, and as bad as that of Van Helmont’s pot of dirty linen. I shall show you where the mice came in. I shall demonstrate that in every experiment of the kind that concerns us here, one must absolutely rule out the use of the mercury trough.” (Barnett, B., 2011)

Here Pasteur directly implied that Pouchet made a mistake and underestimated the importance of the mercury trough in introducing bacteria, as opposed to ensuring its absence. Pasteur went on to demonstrate in a series of experiments that micro-organisms are indeed present in air by using vacuums and filters. He then went on to demonstrate that the liquid mercury used in Pouchet's experiment was a flourishing ground for microbes, which it could easily acquire from the contaminated air; enabling those microbes to multiply. He also went on to show that heat can destroy micro organisms. And then he pointed the finger directly at Pouchet, essentially accusing him of being sloppy and having bad experimental technique.

“In mercury or other compounds which receive microbial spores, all it takes to propagate this possible source of contamination are the non sterile hands of a careless experimenter.” (Barnett, B., 2011)

His conclusion was that when experiments are carried out properly and meticulously, they will remain sterile. This means that the only reason organisms grew in Pouchet's experiment, was because he had contaminated the experiment with imprecise techniques. Pasteur is considered the undisputed winner, and his understanding of microbes led him to many further experiments which took him down the path of a bacteriologist. With his understanding of the functions of fermentation and microbial growth he was able to develop vaccines, pasteurization and sterilization techniques. He is considered one of the most influential scientists of his time and is still seen as a great contributor to modern day science and medicine.

The religious and political points of the debate also need to be considered, because the science is not separable from its political importance. At the time, evolution was seen to have been supported by spontaneous generation, because it essentially constituted of the random combination of molecules. Do keep in mind that Pouchet's version actually claimed to have been divinely guided, as Pouchet was a religious man. However, his stance was not necessarily important for the church who saw spontaneous as a general threat and a tenant of atheistic Darwinism. Paris was quite conservative at the time, and the ruling Catholic church was increasingly intolerance of atheistic science. There had been a raging debate in France over Darwinism, and it was in the political interests of the church to find all of the evidence against Darwinism that it could. Since spontaneous generation could insinuate that molecules pair randomly to create life, this could be seen to support evolution, and that is how it was interpreted by many at that time. Pasteur was a deeply religious man, although at this point in his life he did believe in evolution and not in creation. However, his research, which debunked spontaneous generation, was supported by the political-religious spectrum around him, and his results were thus important for the cause of the church. (Farley, 1982) It is also interesting to note that most of the time Pasteur was unable to 'disprove' Pouchet, and that only 10% of the time did his experiments result in a success rate. The other 90% of the time, he did not publish his findings! In a sense this may sound like someone who is trying awfully hard to prove a biased point, and it even reeks of bad science. How can any respectable scientist not publish 90% of their findings, simply because the findings do not support what they want them to support? Today such behavior would be considered fraudulent and scandalous. However, we can not deny the meticulous nature of Pasteur's work and the major contribution that it made to society. After all, despite all of the religious and political forces undeniably playing in the background of this debate; he was right.

In conclusion, this debate was undeniably fueled by science, ego, religion and politics. Despite all of these obstacles, it resulted in some extremely important discoveries which helped scientists to conduct better experiments in the future because they were aware of contamination. It helped the medical field to understand the importance and nature of the spread of germs, sterilization and contamination, and it also led to numerous vaccines and to pasteurization.

Science will inevitably be tainted by the interests of money and power, and it will always be swayed by deeply held beliefs and values of scientists, ruling institutions and the public. It will always be driven by ego as well, because scientists are human after all. This is something that we can embrace and be aware of while trying to mitigate the influence of such factors. All the while, we cannot forget that they will always inevitably exist, and this does not mean that we cannot make scientific progress regardless. On the other hand, such inevitable human short comings may actually inspire scientific progress to happen. The bottom line is that science is an institution for humans run by humans, and that we cannot separate science from the influence of human strengths, shortcomings and values.

Citations

Barnett, B. (2011, January 1). Pasteur, Pouchet and Heterogenesis. Retrieved November 1, 2014.

Farley, John and Gieson, Gerald l. "Science, Politics and Spontaneous Generation in Nineteenth-Century France: The Pasteur- Pouchet Debate," in Sociology of Scientific Knowledge: A Source Book, edited by H. M. Collins. Bath: Bath University Press, 1982, pp. 1-38. (Originally Bulletin of the History of Medicine 48 (1974), pp. 161-198.)

Farley, John. 1977. The spontaneous generation controversy from Descartes to Oparin. Baltimore: Johns Hopkins University Press.

Hernes, T. (2004). The spatial construction of organization. Amsterdam: J. Benjamins.

Wilkins, J. (2004, January 1). Spontaneous Generation and the Origin of Life by John S. Wilkins Copyright © 2004.