Five Quarts_ A Personal and Natural History of Blood - Bill Hayes [40]
Leeuwenhoek found the same “little eels” in human saliva and other substances, he reported in later correspondence to the Royal Society. Soon scientists, clergymen, and common folk were making the trip to Delft to see for themselves the cloth merchant’s menagerie. That we are surrounded, covered, and filled with countless creepy-crawly microorganisms is such a commonplace understanding today that it’s difficult to imagine how radical—and grotesque—Leeuwenhoek’s images must have seemed three-hundred-odd years ago. His letters are a bracing reminder. “I have had several gentlewomen in my house, who were keen on seeing the little eels in vinegar,” he wrote in 1683, “but some of ’em were so disgusted at the spectacle, that they vowed they’d ne’er use vinegar again. But what if one should tell such people in [the] future that there are more animals living in the scum on the teeth in a man’s mouth, then there are men in a whole kingdom?”
Although Leeuwenhoek always strived to be hospitable, the flood of visitors intruded on his precious work time. During a single four-day period, he once bemoaned, he received twenty-six separate callers. But not all drop-ins were unwelcome. Leeuwenhoek’s makeshift laboratory became a mandatory stop for visiting royalty and heads of state, including King Frederick I of Prussia. Queen Mary of England arrived unannounced one afternoon, but the Delft shopkeeper was not at home. Leeuwenhoek was crushed. This missed meeting, he wrote, “will, and must, be mourned by me all my life.” Henceforth, appointments became mandatory. Another memorable visit came from Russia’s Czar Peter the Great, for whom Leeuwenhoek demonstrated all manner of “microscopical observations,” including, as a grand finale, the movement of blood through the newly discovered capillaries. This never failed to astound people. Leeuwenhoek had designed a special microscope to which he could fasten a small, live fish. Because some fish have transparent tails, one could see blood traveling through the microscopic “tubes” connecting the tiny arteries to the tiny veins. The Russian monarch, who spoke some Dutch, was “so delighted,” a local historian wrote at the time, “that in these and other contemplations he spent no less than two hours, and on taking his leave shook Leeuwenhoek by the hand, and assured him of his special gratitude for letting him see such extreme small objects.” Leeuwenhoek returned the compliment by presenting one of his microscopes as a gift, something he rarely did. Neither did he ever sell his microscopes or teach others how to make them. Anyone who wished to see a Leeuwenhoek microscope had to pay the man a visit.
“Here we go!” Al called out to me from the hallway. With a small box in hand, he returned to his seat and began fashioning a tiny slide from two thin pieces of clear plastic. “Okay, what we’re gonna do first is mount these on the pin with a little bit of beeswax. Oh, look at that!” he said, delighted, halting his work. “Newton’s rings.”
“Huh?”
Al held the plastic shards before me. “Do you see the rainbow-colored rings there, like oil in water?”
“Oh, yes,” I responded.
He smiled. “That’s caused by the interference of the light between the two surfaces. One of Newton’s discoveries.”
Even as he struggled to mount the plastic slide, Al remarked, “We have it so much easier than Leeuwenhoek did. What did he have to do to get a thin piece of flat glass? Window glass would be way too fat, so he had to make it himself!” The trouble Al was having made me realize why Leeuwenhoek got into the habit of leaving difficult-to-mount specimens permanently in place, then making a fresh microscope.
At last Al succeeded in getting the miniature slide onto the Leeuwenhoek replica, a process that had taken a good twenty minutes. And even then, Al wasn’t sure it would work.