ered the bacterial cause of rabies and developed
the first vaccine to prevent the fatal infection in
dogs, the primary source of rabies in his time, as
well as in people bitten by rabid dogs.
Pavlov, Ivan (1849–1936) Russian scientist
best known for his research on conditioned
reflexes, in which he trained dogs to expect food
when he rang a bell. Pavlov observed that after a
time the dogs began to salivate when they heard
the bell ring, altering the body’s normal physio-
logic response to salivate at the sight and smell of
food. Pavlov also used surgical gastric fistulas in
dogs (operations to create openings into the stom-
ach) to study the physiology of digestion, research
for which he won the 1904 Nobel Prize in Physiol-
ogy or Medicine.
Piaget, Jean(1896–1980) Swiss psychologist
who developed numerous theories about human
intelligence, the foundation of which centered
around his belief of intelligence as a process of
adaptation within genetically defined frameworks.
Piaget defined this process through four stages
beginning at birth and culminating in adolescence,
with completion of one stage crucial to entering
the next.
Prusiner, Stanley(b. 1942) American neurol-
ogist and biochemist who discovered prions, infec-
tious protein fragments that cause progressive,
degenerative brain diseases such as kuru disease,
Creutzfeldt-Jakob disease (CJD), and variant CJD
(vCJD) arising from infection with bovine spongi-
form encephalopathy (BSE; commonly called mad
cow disease). Prusiner received the Nobel Prize in
Physiology or Medicine in 1997 for his discovery
and work in understanding the infectious mecha-
nisms of prions.
Roëntgen, Wilhelm (1845–1923) German
physicist who discovered X-rays and the process
for using them to create images, called
roentgenograms, which revealed internal struc-
tures of density such as the bones. Roëntgen
received the Nobel Prize in Physiology or Medi-
cine in 1901 for his discoveries.
Sabin, Florence(1871–1953) American physi-
cian who was the first woman to become a full
professor at Johns Hopkins Medical School. Sabin
conducted research that resulted in significant
findings about the structure of the brain, fetal
development of the lymphatic system, and tuber-
culosis infection. In the latter years of her medical
career Sabin turned her efforts to public health in
her home state of Colorado.
Salk, Jonas(1914–1995) American physician
who developed the first polio vaccine, released in
1955 after eight years of research. Polio vaccina-
tion has eradicated poliomyelitis, once one of the
most debilitating and often fatal infections, from
much of the world.
Semmelweis, Ignaz Philipp (1818–1861)
Hungarian physician who recognized the connec-
tion between puerperal fever (childbirth fever)
and the then-common practice physicians fol-
lowed of moving between autopsies on women
who died and women who had just given birth.
Semmelweis implemented stringent antisepsis
procedures at the hospital where he worked,
requiring physicians to wash their hands with
chlorinated lime before examining patients. As a
result the death rate dropped to nearly zero.
Though the established medical community was
slow to embrace this revolutionary change, anti-
septic hand washing eventually became standard
practice.
Soper, Fred(1893–1977) American epidemi-
ologist who organized vector-eradication programs
worldwide to eliminate diseases such as malaria,
yellow fever, and hookworm infestation.
Taussig, Helen(1898–1986) American pedia-
trician and cardiologist who worked with heart
surgeon Alfred Blalock and surgical researcher
Vivien Thomas to develop an operation to correct
severe congenital defects of the heart. The first
such operation, the Blalock-Taussig procedure,
was a shunt that restored the flow of blood
through the lungs in defects such as tetralogy of
Fallot. Taussig overcame a severe hearing loss suf-
fered in childhood as well as bias that prevented
women from obtaining medical degrees at most
medical schools in the United States.
Thomas, Vivien(1910–1985) African Ameri-
can researcher who collaborated with heart sur-
geon Alfred Blalock and pediatrician Helen Taussig
to develop the operative procedures and instru-
ments to correct congenital heart defects. Intend-
ing himself to become a physician, Thomas lost his
savings in the stock market crash of 1929 that
ushered in the American Great Depression. By the
time he recovered financially, changing educa-Biographies of Notable Personalities 415