Boyle's Law?, Bunsen's Burner?, Petri's Dish,
and the Politics of Scientific Renown
by Douglas Allchin
The Bunsen burner is such a familiar fixture of chemistry labs that its reputation reaches students even before they enter the classroom. As an icon of science, it permeates popular culture. But where did the Bunsen burner come from? Who invented it? You might hope to chuckle at the absurdly obvious: "why, Bunsen, of course!" But a brief foray into history may be warranted before placing too significant a wager on the "obvious."
Robert Bunsen, whose name we associate with the burner, was a 19th-century German chemist of some renown. He worked on explosive organic arsenic compounds--leading to the loss of one eye--and, later, on gases from volcanoes, geysers and blast furnaces. With Kirchoff he contributed to our understanding of the meaning of spectra lines. (He also gained note for not bathing--one woman of polite society remarked that Bunsen was so charming that she would like to kiss him, but she would have to wash him first.) Bunsen invented many bits of laboratory apparatus: the spectroscope, the carbon-pole battery, an ice calorimeter and vapor calorimeter, the thermopile, and the filter pump--but not, as one might imagine, the gas burner that bears his name. Rather, the "Bunsen" burner was developed by Bunsen's laboratory assistant, Peter Desdega. Desdega himself likely borrowed from earlier designs by Aimé Argand and Michael Faraday. So why does Bunsen get the implicit credit? --And why do we know so little about Desdega that we cannot add much to his story?
"Bunsen's" burner illustrates an important dimension of science frequently omitted in teaching about science: professional credit. Eponymous laws and labels--whose names reflect their discoverers--appear throughout science: Snell's law of refraction, Gay-Lussac's law of gases, the Hardy-Weinberg model of population genetics, the volt (named for Alexander Volta), etc. The naming of laws for their discoverers seems appropriate for honoring the scientists--and the human names are handy for reminding students that science is done by real persons. But in this system, one person and only one person gets all the credit. Focusing on great individuals can hide the collective nature of science, especially the role of technicians such as Desdega. How do we distribute the credit where appropriate?
The great Isaac Newton is frequently quoted for expressing the humbling effect of the collective effort in science: "If I have seen further," he once professed, "it is by standing on the shoulders of giants." Newton's claim, we now know, betrayed a false modesty. Newton's bitter priority dispute with Leibniz over the invention of the calculus, in particular, bears witness to his ambition and obsession with prestige--and his political maneuvers in trying to achieve it. In that case, at least, Newton tried to further his own stature "by standing on the claims of competitors." In similar ways, perhaps, the contributions of technical workers often get buried when we allow theoretical discoveries of the work of their masters to overshadow them. Bunsen's burner--or perhaps the Desdega burner--is a notable example.
The story of the Petri dish is an interesting exception--while at the same time underscoring the general pattern of invisible technicians. Julius Richard Petri (1852-1921) worked for the master of "germ theory" in Germany in the late 1800s, Robert Koch (1843-1910; pronounced as a gutteral "coke"). Initially, bacteria were cultured in liquid broth--a practice captured in our famous images of experiments on spontaneous generation. But Koch saw the advantage of growing bacteria on a solid medium instead. By spreading out mixtures of microorganisms on a solid surface, he could separate individual types in isolated colonies. With pure colonies, he could investigate the effects of each bacterium. The method allowed Koch to identify the specific organisms that cause tuberculosis, cholera, diptheria, among many other diseases--and then to develop vaccines.
At first, however, Koch used a "puddle" of gelatin on a flat piece of glass. Later, the gelatin was spread on the side of a flat bottle, accessed through a narrow opening at the end. Petri, however, realized that one could pour the gelatin in a shallow dish, and put a cover on it, making it easier to get at the bacterial cultures. Since then, of course, the Petri dish has become a staple in laboratory work--and not just in studying microbes. Koch's work is certainly remembered (though oddly his name does not carry beyond the world of microbiologists, say in the way that Pasteur's has). At the same time, the name of Koch's assistant has become a household word, though few know exactly who he was!
Consider, finally, the bane of many a chemistry student: Boyle's law. While many students learn this classic rule of the behavior of gases as P1V1 = P2V2 or PV = k, Robert Boyle never expressed it in these terms. Nor did he ever regard it as a "natural law." Moreover, Boyle was only one among many who revealed the regularity involved here. There is much to untangle in the simple name.
Does the form of expression of Boyle's law matter? Perhaps not. The phenomeon--the "Spring of Air," as Boyle called it--remains the same. Still, it may be important to remember that Boyle first investigated the the spring of air without quantification, and even later without summarizing the relationship in a mathematical formula or equation. Students, likewise, may well be able to understand what Boyle understood--without solving problems using a formula that someone else added much later. Here, crediting Boyle with "Boyle's law" belies an underlying complexity in the concept as expressed in modern texts.
Would Boyle himself have recognized "Boyle's law"? Probably not. He would likely have demurred from expressing his findings as a "law," for instance. For Boyle and others of his day, laws were universal, and they expressed principles of how nature should act (akin to human laws). But Boyle saw his work as simple induction, merely expressing a regularity of nature--not as the discovery of any fundamental causal relationship. Further, Boyle had no concept of gases as we know them today, only of air, and he considered the properties of air variable. This was reflected, for example, in Torricelli's tube (today's barometer), which showed the varying pressure of the atmosphere. Our concept of "law" is our concept, not Boyle's.
What of the discovery itself? Boyle himself did originally formulate and test the reciprocal relationship of pressure and volume of air for pressures greater than one atmosphere. But it was Boyle's assistant, Richard Townley, who extrapolated his notion to pressures lower than one atmosphere. Townley speculated on the air at the top of a Torricelli tube at high altitudes--where he knew the volume to be expanded. It was Townley's reflections that suggested to Boyle further experiments on quantifying the rarefaction of the air. Boyle, however, published the work and carried with him the credit.
Boyle also relied on others in constructing his experiment. To rarefy the atmosphere, Boyle used an air pump--designed and built mostly by another assistant (who later gained fame on his own), Robert Hooke. In addition, yet another asssitant, Ralf Gratorix, participated in building the apparatus and perhaps in executing the experiments. Even the mathematical table that Boyle used to express his final results and compare them against theoretical expectations was probably Hooke's idea, as well. Boyle was a "gentleman" scientist--and was more forthright than most in acknowledging his technical assitants--yet he certainly now carries all the credit for work that was only partly his.
To make matters worse, what most English-speakers know as "Boyle's" Law is known in France as Mariotte's Law--supposedly discovered by the French cleric, Edmé Mariotte. Mariotte published later than Boyle. Did he thus "borrow" from Boyle's work, or did he discover the relationship independently? We don't know. At the time, there were not clear principles whereby Mariotte was obliged to recognize Boyle's work. Mariotte did claim to have found a "law" however, and to have tested it. Does his boldness or confdience deserve credit? Or does the French persistence in referring to Mariotte's Law represent a nationalistic effort to keep British achievements in shadow?
The tradition of professional credit was developed in the late 1600s in part to encourage those who made discoveries to share their work and allow others to build on them. Previously, the pursuit of knowledge had often been considered private (or privileged), or the knowledge gained was worth keeping secret. Hence, to encourage investigators to make their findings public, the Royal Society of London adopted a policy of bestowing honor only on the first to publish a particular discovery, much in the spirit of copyright law. Science became public. With it, however, came the competition for priority and exclusive credit. Did the contributions of Dresdega, Townley, Hooke, Gratorix, and others ultimately suffer as a result?
The stories of familiar items in school science raise questions for students in interpreting science even today. Who gets credit, and why? How does credit get distributed? Who really does the work of science?