In all the years that medical researchers have been studying and describing the virus of poliomyelitis, they had never seen the critter. Now, two teams of investigators working independently have isolated the virus, looked at it long and hard under the electron microscope, photographed it and measured it. It turns out to be a spherical particle almost exactly a millionth of an inch in diameter. Magnified tens of thousands of times against a plastic screen, the virus particles look like tennis balls on an asphalt court.
The reason for the long delay in completely isolating the virus was the difficulty of separating...
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