Before approaching matters of taste, I'll explain AvL. To many of our readers, the meaning of the acronym will be immediately apparent. But to others, perhaps those newer to microbiology, it may have no meaning at all. AvL is short for Antonie van Leeuwenhoek, considered by many as the "father of microbiology." I hope you will agree that the name is long enough to merit an acronym when appearing repeatedly. At STC (meaning Small Things Considered ;-)) we have paid homage to AvL numerous times. See, as examples, a tribute to him as natural philosopher or Christoph's post describing him as the first to investigate dental plaque with the aid of a microscope. AvL was interested in many and diverse subjects and, when he was interested in a subject, he quickly put it under the microscope.
AvL is, of course, recognized as the first to observe individual bacteria. How did he come about this towering discovery? It was due to his interest in the sense of taste (in 1983, D. Bardell published a fun-to-read paper of this history). On a letter to the Royal Society dated 19 October 1674 AvL wrotse: "Last winter while being sickly and nearly unable to taste, I examined the appearance of my tongue, which was very furred, in a mirror, and judged that my loss of tasted was caused by the thick skin on the tongue." While he did not find bacteria through these observations, he did study ox tongues through the microscope and described what we now know to be gustatory papillae as "very fine pointed projections" composed of "very small globules." He concluded that the "thick skin" on his tongue interfered with the projections' ability to sense taste during his illness. He hypothesized that when exposed to food these projections were stimulated differently by tiny crystals of different shapes present in the food. To investigate this further, AvL decided to look at what shapes of crystals he might find in black pepper which might account for its strong taste. What he found was something else, something completely unforeseen: bacteria.
AvL's experiment was simple. He left peppercorns standing in water for three weeks to extract the strong flavor and observe. He described his obervations in a letter to the Royal Society dated 19 October 1676. Alas! AvL did not discover what renders black pepper spicy. Instead, he saw more of his beloved "kleijne dierken" (little animals, later translated as animalcules). But much to his surprise, he also saw organisms that were "incredibly small," much smaller than the "kleijne dierken." He estimated that one million of them would not amount to the size of a grain of sand. From this size description we now surmise that AvL discovered individual bacteria in this experiment. His later observations, particularly those involving dental plaque, served as strong confirmation of the existence of such incredibly small organisms, our beloved bacteria.
If you want more on AvL, on Monday Christoph will discuss another "kleijne dierken."