Britannica Student Encyclopedia - 2010

The cathedral of Vilnius stands at the end of

a street in the city’s Old Town. The original

cathedral was built in the 1300s. The current

building dates from 1801.

BRITANNICA STUDENT ENCYCLOPEDIA Vilnius 91

 

became a fully independent country.

Vilnius once again became its capital.

#More to explore

Holocaust • Lithuania

Vinegar

Vinegar is a sour liquid that is used to

flavor and preserve food. It is made by

putting alcohol through a chemical

change called fermentation.

The word vinegar comes from the

French words for sour wine. Vinegar

that is made from grapes is called wine

vinegar. But vinegar can be made from

other foods as well. Vinegar made from

apples is called cider vinegar. Vinegar

made from barley or oats is called malt

vinegar.

The process of making vinegar starts

with liquid that comes from the grapes,

apples, or other foods. When a substance

called yeast is added to the liquid

it converts sugars in the liquid into alcohol.

Tiny living things called Acetobacter

bacteria then make the alcohol combine

with oxygen in the air to form acetic

acid and water. The acetic acid is what

gives vinegar its sour taste.

Acetic acid is a strong acid. The vinegar

that is sold in supermarkets is only

about 4 percent acetic acid.Water and

flavorings make up the other 96 percent.

Vinegar is used to add a sour taste to

foods. Cooks make a sour salad dressing

called vinaigrette by mixing vinegar with

cooking oil and spices. Cooks also use

vinegar to preserve foods. This practice

is called pickling. Pickles are cucumbers

that have been pickled. Many other

kinds of vegetables and fish can also be

pickled.

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Acid and Base • Fermentation

Violet

Violets are popular garden plants with

delicate flowers. They also grow in the

wild. There are about 500 species, or

types, of violet. They include the common

blue violet and the pansy. The

popular houseplants called African violets

are not in the same family as true

violets.

Violets grow in places that have warm

summers and cold winters. They are

hardy plants and can grow well under

trees and shrubs. The smallest violets are

about 2 inches (5 centimeters) high. The

largest can reach a height of more than

20 inches (50 centimeters).

Some people

use vinegar to

treat wasp

stings. However,

the vinegar

treatment

probably does

not work.

The common blue violet has heart-shaped

leaves and purple or white flowers.

92 Vinegar BRITANNICA STUDENT ENCYCLOPEDIA

 

Violets often have large, heart-shaped

leaves. The flowers have five petals. They

are most commonly deep purple, blue,

or lavender. They also can be white,

yellow, reddish purple, or a combination

of colors.

Some people eat the flowers of violets.

In addition, sweet-smelling violets are

used to make perfume.

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Flower • Plant

Viper

The vipers are a group of poisonous

snakes that have sharp fangs. There are

about 200 species, or types, of viper.

Some of the deadliest snakes in the

world are vipers.Well-known types

include rattlesnakes and adders.

Vipers are found throughout the world

except in Australia and Antarctica. They

live in both dry and wet climates. Vipers

may spend time on the ground, in trees,

or in water.

Some vipers are less than a foot (30

centimeters) long. Others are more than

10 feet (3 meters) long. A viper’s body

may be thin or thick. The color ranges

from tan to black to green. Vipers

blend in well with their surroundings.

This helps to protect them from their

enemies.

Vipers have a triangular head. Many

have scales that stand up straight above

their eyes. These scales make it seem like

the snake has horns. Vipers have long

fangs compared to other snakes. When a

viper closes its jaw, its fangs fold up

against the roof of its mouth. Some

female vipers lay eggs. Others give birth

to live young.

Vipers do not really hunt for food.

Instead they wait for small animals to

come to them. Once a prey animal is

near, a viper bites quickly and injects

venom, or poison, into it. The prey usually

dies nearby. The viper then finds the

prey using its sense of smell. It swallows

the prey whole.

Some types of viper are called pit vipers.

Pit vipers have special organs called pits

on both sides of their face. These pits

help them sense heat coming from the

body of their prey. Once a pit viper

senses the heat, it can attack its prey

even in the dark. Pit vipers include

rattlesnakes, copperheads, fer-de-lances,

and moccasins.

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Rattlesnake • Snake

The common adder is a viper. Common

adders live on the island of Great Britain

and in many other parts of Europe and Asia.

BRITANNICA STUDENT ENCYCLOPEDIA Viper 93

 

Virginia

Virginia has one of the longest

continuous histories among the

U.S. states. Its history dates back to the

English settlement of Jamestown in

1607. Virginia was named for Queen

Elizabeth I of England. She was often

called the Virgin Queen because she

never married. The state is also referred

to as the Birthplace of Presidents. Eight

presidents of the United States were

born in Virginia, including George

Washington and Thomas Jefferson.

Richmond is the capital.

Geography

Virginia is located in the southeastern