mixed with sugar and milk to make hot
chocolate drinks.
Chocolate for eating is made by adding
extra cocoa butter to chocolate liquor.
To make dark chocolate, workers add
sugar to this mixture. Adding both sugar
and milk makes milk chocolate. Mixing
cocoa butter, sugar, and milk makes
white chocolate. These mixtures may be
poured into molds to make different
shapes of candy.
Chocolate bars contain cocoa butter and
cocoa liquor made from the seeds of the
cacao tree.
The seeds from cacao trees are dried to
make cocoa beans (left). Cocoa powder is
made from crushed cocoa beans.
108 Chocolate BRITANNICA STUDENT ENCYCLOPEDIA
History
Chocolate’s popularity began in ancient
Mexico and Central America, where the
cacao tree grew wild. The Maya and
Aztec peoples prepared a hot, bitter
drink with cocoa beans. In 1519 the
Aztec emperor Montezuma II served the
Spanish explorer Hernan Cortes a
chocolate drink called xocoatl.
Cortes brought this beverage back to
Spain.With sugar, vanilla, and cinnamon
added, it became a favorite with
the Spanish kings and queens. In the
1600s the drink became popular among
rich people in France and England.
In the 1800s people discovered how to
make smooth, tasty chocolate for eating.
Today the top chocolate-producing
countries include the United States, the
United Kingdom, Switzerland, Germany,
The Netherlands, and France.
#More to explore
Aztec • Food and Nutrition
Choctaw
The Choctaw are a large Native American
tribe that once lived in what is now
southern Mississippi. They were probably
descended from earlier peoples
known as mound builders.
Choctaw villages were clusters of houses
made from wood frames covered with
mud. The roofs were made from grass or
cane reeds. Choctaw women tended
fields of corn, beans, and pumpkins.
They also gathered wild fruits and nuts.
Men fished and hunted for deer and bear.
A painting from the 1800s shows Choctaw men playing a traditional ball game on a large
field with tall goalposts.
BRITANNICA STUDENT ENCYCLOPEDIA Choctaw 109
In the 1540s the Choctaw drove
Spanish explorers out of their territory.
The tribe was friendlier to the French,
who became valued trading partners. In
the American Revolution (1775–83)
the Choctaw sided with the Americans
against the British. They adopted
enough American customs to be
regarded as one of the Five Civilized
Tribes (along with the Chickasaw, the
Seminole, the Cherokee, and the
Creek).
In 1830 a small group of Choctaw
agreed to give the United States their
territory in the Southeast in exchange
for land in Indian Territory (later
Oklahoma). Most Choctaw did not
want to leave, but U.S. troops forced
them to make the trip. Thousands died
on the march. By the late 1800s settlers
had taken over much of the new
Choctaw territory. In 1907 the land
became part of Oklahoma. At the end
of the 20th century there were about
87,000 Choctaw, mostly in Oklahoma
and Mississippi.
#More to explore
Cherokee • Chickasaw • Creek • Mound
Builder • Native Americans • Seminole
Cholera
The disease called cholera is an infection
of the small intestine. It causes the body
to lose important fluids and minerals.
Outbreaks of cholera have quickly killed
many thousands of people.
Cholera is caused by a certain kind of
bacteria. A person gets the disease by
eating food or drinking water that has
been contaminated, or infected, with the
bacteria.
Diarrhea is usually the first symptom, or
sign, of cholera. Vomiting follows the
diarrhea. The body rapidly loses large
amounts of water and other fluids. The
result is a condition called dehydration.
The person has a strong thirst and painful
muscle cramps. If the dehydration is
not treated, the patient may die within a
few hours.
Doctors treat cholera mainly by
replacing the body’s lost fluids. The
person may be given fluids to drink.
The fluids contain both water and
minerals. The doctor also may give the
person fluids through a tube that is
inserted into a blood vessel. Sometimes
the person is given a medicine called an
antibiotic.
Cholera often occurs in countries that
do not have good sanitation equipment.
Since 1817
cholera has
swept from
country to
country seven
times, killing
millions of
people.
A health worker shows a family in Afghanistan
how to use tablets to make water safe
to drink. Cholera can spread through contaminated
water.
110 Cholera BRITANNICA STUDENT ENCYCLOPEDIA
The best prevention for cholera is making
sure that the water supply is clean.
Sometimes people are given a vaccine to
protect them from the disease.
#More to explore
Antibiotic • Bacteria • Intestines
• Vaccine
Cholesterol
Cholesterol is a waxy material that forms
in the human body. The body needs
cholesterol in order to work. It helps
form vitamin D and other products. But
too much cholesterol can hurt the body.
Most cholesterol is made in the liver.
Certain chemicals called proteins carry it
through the bloodstream. Two such proteins
are called low-density lipoproteins
(LDLs) and high-density lipoproteins
(HDLs).
LDLs bring cholesterol from the liver to
other cells. After arriving where it is
needed, the cholesterol leaves the LDL.
The role of HDLs is not as clear. HDLs
