Schleiden and Schwann introduced the cell theory of life in the early nineteenth century. The discovery of a Lilliputian world had begun. Leeuwenhoek was the first person to see a bacterial cell. Galileo was one of the first to use a crude microscope to observe the compound eyes of insects.
In order to proceed, biology needed a breakthrough. One black box had been opened only to reveal another. The human eye can resolve objects as small as one-tenth of a millimeter, but so much remained to be discovered on a minuscule, or Lilliputian scale. He concluded that since making that much blood in such a short time span would be impossible, it must be recirculated.Īlthough advances came more rapidly in the seventeenth and eighteenth centuries, they were hampered by being limited to what was visible to the naked eye. In the seventeenth century, an Englishman, William Harvey, calculated that if the heart pumps out just two ounces of blood per beat, at 72 beats per minute, in one hour it would pump 540 pounds of blood. This misunderstanding would be taught for nearly fifteen hundred years. He used dissection to understand animal organs, and although he knew the heart pumped blood, he mistakenly concluded that blood was continuously made and then pumped out to irrigate the tissues. Galen, a second-century physician, was one of only a few biological investigators to live in the millennium to follow. The human body was believed to be made of blood, yellow bile, black bile and phlegm all disease was thought to arise from an imbalance of these four elements.Īristotle systematically observed nature and was the first to group animals into two categories-those with and those without blood.
The ancients believed that all matter was made up of earth, air, fire and water. In ancient times, all of biology was a black box. A black box is an enigma-something with mysterious inner workings.
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