- News Home
10 April 2014 11:44 am ,
Vol. 344 ,
The Pyrenean ibex, an impressive mountain goat that lived in the central Pyrenees in Spain, went extinct in 2000. But a...
Tight budgets are forcing NASA to consider turning off one or more planetary science projects that have completed their...
Ebola is not a stranger to West Africa—an outbreak in the 1990s killed chimpanzees and sickened one researcher. But the...
In an as-yet-unpublished report, an international panel of geoscientists has concluded that a pair of deadly...
Tropical disease experts tried and failed before to eradicate yaws, a rare disfiguring disease of poor countries. Now,...
Since 2002, researchers have reported that agricultural communities in the hot and humid Pacific Coast of Central...
Balkan endemic kidney disease surfaced in the 1950s and for decades defied attempts to finger the cause. It occurred...
- 10 April 2014 11:44 am , Vol. 344 , #6180
- About Us
A Trick of the Eye
17 December 1997 8:00 pm
Jan Purkinje, a histologist and physiologist whose findings led to important insights into how the body works, was born on this day in 1787. Purkinje is famous for explaining visual phenomena: the Purkinje effect describes how blue objects appear brighter than red objects in dimmer light. And Purkinje's images are the threefold reflections seen in the eye of another person, caused by an object reflecting from the cornea's surface and both sides of the lens.
Purkinje also discovered the large nerve cells with numerous dendrites in the cerebellum. He was the first to identify unusual muscle fibers in the membrane lining the heart, now known to conduct the pacemaker stimulus. He was also the first to spot the sweat glands by sight, not smell. In his spare time, Purkinje improved techniques for preparing tissue samples, using a microtome--an instrument that slices tissues into very thin samples.
[Source: Roy Porter, Ed. The Biographical Dictionary of Scientists, Second Edition. Oxford University Press. 1994.]