I’ve been away from this blog for a few months while working away on my dissertation. But, having given a draft over to my committee, I thought I should take the opportunity to articulate on paper (or “on blog” rather) a topic that I’ve been thinking about now for some time: can we bridge the history of medicine and the history of oceanography? Certainly a history could be written about the extraction of medical resources from the ocean. In recent years marine natural products have become an important field of biochemical research. Or, we could discuss the development of “naval” medicine (think: Captain James Cook’s experiments with antiscorbutics in the late 18th century). Both are interesting topics to pursue. But, looking broadly at historical developments in medicine, and historical developments in oceanography, where are the points of intersection, and how can these fields of scholarship inform one another? I don’t yet pretend to have definitive answers for these questions, but I hope my discussion will stimulate further thinking on this topic.
While researching the life and work of Prince Albert Ist of Monaco, I unexpectedly came across an interesting episode in the history of medicine. The events are described in detail in the July 1991 issue of the History of Oceanography Newsletter, (predecessor to this blog) by deep-sea oceanographer and historian Tony Rice, and I have relied heavily of his description of events for the following account. [Another detailed account can be found here.]
In 1901, when Prince Albert set out on his usual summer research cruise aboard his yacht the Princess Alice II, he invited along two French scientists, Charles Richet (1850 – 1935), professor of physiology at the University of Paris, and Paul Portier (1866 – 1962), assistant in the laboratory of physiology at the Sorbonne. They set sail from Toulon on the 5th of July, bound for the canaries, Madeira, and the Azores. Portier and Richet’s intention was to study marine bacteria. This was a field of study that was still quite young, inaugurated only twenty years earlier during the French state-sponsored voyages of the Talisman and Travailleur by Adrien Certes. However, Prince Albert encouraged Portier and Richet to the study of the toxins of the Physalia physalis, better known as the Portuguese Man-o-war.
Prince Albert and Jules Richard, his chief scientific collaborator, had a long-standing interest in man-o-war toxin. They had previously observed that fish, once stung by Physalia, were rendered immobile while remaining alive. Portier and Richet performed numerous experiments injecting toxin extracted from Physalia into various animals brought along for experiment in the ship’s laboratory. Observing that the toxin rendered “ducks, pigeons, guinea pigs, and frogs” immobile and seemingly unconscious, they named the venom “hypnotoxin.” Once they returned to Paris they decided to continue these experiments. But, back on land, obtaining specimens of Physalia was naturally much more difficult. Thus, Portier and Richet began experimenting with another marine biological toxin, that of the snakelocks sea anemone, easily obtainable at the Roscoff marine biological laboratory in Brittany. This time they injected the toxin into dogs, which produced a similar and frequently lethal reaction.
Here the research took on a new dimension; having determined the quantity of toxin required for a lethal dosage, Portier and Richet began experimenting with injections just below the lethal threshold. They discovered that animals exposed to one dosage became hypersensitive to a second exposure. As Tony Rice has suggested, these results likely ran counter to their expectations. It seems probably that they were trying to apply Pasteur’s theory of bacterial immunity to toxic venoms and that they would thus have expected greater resistance in their test subjects to the second injection of toxin. However, subsequent experiments demonstrated that the more extended the time interval between injections, the more severe the second reaction.
This physiological response they named “anaphylaxis,” from the greek “ana” meaning “again,” and “phulaxis,” meaning “guarding.” This discovery led the way to a radical shift in the medical understanding of allergic reactions and, in 1913, Richet was awarded the Nobel Prize in physiology in recognition for his work. (Portier, perhaps unfairly, did not share the prize with Richet.) But, for the purpose of my argument, it is important to note that this was not the end of Portier’s collaboration with Prince Albert, or indeed of his work in marine science. In 1903 we find him again aboard the Princess Alice II, this time in collaboration with Jules Richard, testing a new instrument for the retrieval bacterial samples from the water column. For over two years, he and Richard perfected their device – which they named simply the “bacterial bottle” – constituting a valuable contribution to the nascent field of marine microbiology.
So why does this story matter for the history of oceanography? Well, it is a reminder that the history of oceanography and medicine has been, and remains, entangled. I want to give two more examples to support this argument. The first is important because it demonstrates the broad impact that one fairly mundane marine biological discovery had on the field of medicine – a discovery from which everyone reading this has at some point benefited. The second example demonstrates how a technological development in physical oceanography, a product of the space age, brought about a life-saving public health initiative in the developing world.
Vaccinations, Prosthetics, and Horseshoe Crabs:
One quart of horseshoe crab (Limulus) blood has an estimated value of $15,000. The horseshoe crab blood industry (yes, there is such a thing) has an estimated value of $50 million per year. How did this come to be? Well, it’s a story that began in 1885 when W. H. Howell (1860 – 1945) of Johns Hopkins University described the unusual clotting properties of horseshoe crab blood. It was no accident that he had begun studying horseshoe crab morphology, for horseshoe crabs were incredibly abundant along the eastern seaboard of the United States in the late nineteenth and early twentieth centuries. So abundant were they, that they were commonly used for agricultural fertilizer and livestock feed. And, though the horseshoe crab population has since declined substantially, they are still used as fishing bait today.
The accessibility of horseshoe crabs – notably, proximity to horseshoe crab spawning grounds – was an important consideration when the Marine Biological Laboratory was founded in Woods Hole in 1888. MBL soon became the principal center for horseshoe crab research in the United States. The research with the most lasting impact was carried out by Leo Loeb (1869 – 1959), a German-born experimental pathologist. Following the discoveries of Howell, Leob conducted numerous detailed studies of horseshoe crab blood and circulatory systems at Woods Hole in the 1910s and 1920s. The most important discovery, however, took place in the early 1950s when Frederick Bang (1916 – 1981) was finally able to identify the horseshoe blood clotting mechanism. These findings were published in a 1955 article, entitled “A Bacterial Disease of Limulus Polyphemus.” On the brink of a breakthrough of incredible importance for medicine, it is interesting to note that Bang writes in his discussion that: “Limulus was chosen for these studies largely as a matter of convenience and availability.”
The key finding was that horseshoe crabs possess a unique chemical within the amoebocyte cells in their blood plasma. This chemical, coagulogen, allows these mobile cells to quickly identify the presence of minute quantities of foreign bacteria. As an immune response, the amoebocytes then clot the blood, effectively trapping and isolating the contaminant. Pharmaceutical companies quickly recognized the potential medical applications of this biological mechanism. Today, five companies specialize in the capture and bleeding of horseshoe crabs in order to extract coagulogen from their blood. The chemical is used to test for the presence of contaminants in everything from intravenous drugs to surgical implants and prosthetics – anything that comes into contact with human blood. This test is called the Limulus amebocyte lysate test, or LAL for short, and this is how a seemingly commonplace marine biological laboratory organism became the foundation for a $50 million a year pharmaceutical industry.
Satellites, Sarees, Copepods, and Cholera:
Finally, I want to turn to my second example of the overlap between oceanography and medicine. After many years of study, Rita Colwell (the first female director of NSF, then working as a marine microbiologist at the University of Maryland) and her collaborators were able to demonstrate that the bacteria, Vibrio cholerae, had a commensal relationship with copepods. In other words, they determined that part of the cholera bacteria’s life cycle takes place in or on the bodies of zooplankton, copepods in particular. By the early 1990s, it became possible to measure sea-surface temperature and height using satellite telemetry. Colwell and her colleagues soon noted a correlation between the annual cycle of sea-surface temperature change and cholera outbreaks in the Bay of Bengal. As the sea-surface temperature went up, so did the number of outbreaks. It soon became clear that warming (higher) seawater was more likely to mix with low-lying tidal rivers. Cholera bacteria carrying copepods were then moving upstream where they were infecting the people who used the rivers for drinking, cooking, and washing. Satellites could also detect changing chlorophyll levels in the sea-surface, making it easier to detect plankton blooms when the population of copepods also increased. This discovery led to an intensive health campaign in Bangladesh. Villagers were shown that if they folded their sarees at least four times and used them as filters they could remove copepods from their drinking water, in turn lowering their risk of cholera infection.
So where do these three case studies leave us? Well, I think it’s helpful to refer to the words of Dr. Eric Mills who, in defining the history of oceanography in 1990, wrote: “Definitions turn out to be cramping, inhibitory, and worst of all, an unadventurous aid to our scholarship. History of oceanography is what historians of oceanography write about.” As we continue to move our discipline forward, we should not be afraid to examine the potential areas of overlap between our field of study and other branches of historical scholarship. Increasingly, for instance, we have come to recognize the ways in which the methods and theories of environmental history can be applied to the history of oceanography. We should be on the lookout for other similar opportunities, and the history of medicine may offer new directions for research.