• Telescopes and Microscopes—Advances From Yesterday to Our Day
    Awake!—1984 | September 22

    • Seeing the Hidden World

      The world of the microscopically small is no less fascinating. Driven by insatiable curiosity, Leeuwenhoek used to study just about anything he could fit under his lens. Once he took some saliva from his mouth and examined it under his microscope. To his surprise he saw “many very little living animalcules [little animals], very prettily a-moving.” He then sent a description and drawing of these mouth bacteria to the Royal Society of London in 1683. “What if one should tell,” later exclaimed Leeuwenhoek, “that there are more animals living in the scum on the teeth in a man’s mouth, than there are men in a whole kingdom?” Modern estimates of the number of microorganisms living in the human mouth run into the billions.

      Indeed, scientists peering into that hidden world have discovered things that would have astounded even Leeuwenhoek. They can now, for instance, see that a simple drop of blood may contain some 35 million red cells. Each cell, in turn, may contain more than 280 million hemoglobin molecules. “Imagine the task of mapping the 10,000 atoms of just one hemoglobin molecule,” exclaimed Dr. Coppedge in his book Evolution: Possible or Impossible?

      Microorganisms​—Good or Bad?

      Many of us naturally recoil at the very thought of germs. And it is true that some microorganisms cause sickness and death. However, this appears to be the exception rather than the rule.

      For example, do you enjoy a glass of milk? Well, it takes trillions of microorganisms in a cow’s stomach to enable it to digest fodder and produce milk. Benign germs also dwell in a human’s intestines. Says the textbook Elements of Microbiology: “Many intestinal bacteria can synthesize the major B vitamins and vitamins E and K. Vitamins so produced make a significant contribution to the vitamin requirements of the host.”

      Tiny microorganisms even act as an efficient sanitation department. “If microbes did not deal with dead and waste matter,” wrote science writer Ludovici, “it would pile up to such an extent that we should die for lack of space. It really is no exaggeration to say our existence depends on microbes, on an invisible world that comes into view with the help of the microscope.”

      With improved equipment, biologists can even get a closer look at the microorganisms themselves. These, too, are amazingly complex. Some microorganisms possess a whiplike tail called a flagellum. It is fascinating to look through a microscope and watch them darting about in a mere drop of water! One kind of bacterium (called Spirillum serpens) even has tails that spin like electric propellers. (It has been clocked at 2,400 rpm!) And if this minisubmarine needs to change directions, it simply switches on at the opposite end!

      Microscopes​—The State of the Art

      Leeuwenhoek’s homemade devices could, amazingly enough, magnify objects 250 times or more. Optical microscopes today, however, can magnify objects about a thousand times. “The common housefly magnified to the same extent would appear to be more than 30 ft [9 m] long,” explains the book Elements of Microbiology.

      In 1931 the electron microscope was invented. By aiming a stream of electrons at an object, a visual image can be produced in which objects are magnified about a million times. There is one serious drawback: It cannot be used to study living specimens. A new device, however, which combines the optical microscope with television cameras and computer memory, now makes it possible for scientists actually to observe the biological activity of living cells! Reported The New York Times: “Ducts, or microfilaments, only a millionth of an inch in diameter, can be seen transporting such particles as food and waste in opposite directions at the same time.”