What Is
Smell?
Jennifer Boothroyd
For Jacob
Copyright 2010 by Lerner Publishing Group, Inc. All rights reserved. International copyright secured. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any meanselectronic, mechanical, photocopying, recording, or otherwisewithout the prior written permission of Lerner Publishing Group, Inc., except for the inclusion of brief quotations in an acknowledged review. Lerner Publications Company A division of Lerner Publishing Group, Inc. 241 First Avenue North Minneapolis, MN 55401 U.S.A.
Website address: www.lernerbooks.com Library of Congress Cataloging-in-Publication Data What is smell? / by Jennifer Boothroyd. p. cm. (Lightning bolt booksTMYour amazing senses) Includes index. ISBN 9780761342533 (lib. : alk. paper) 1. paper) 1.
SmellJuvenile literature. I. Title. QP458.B67 2010 612.86dc22 2008051850 Manufactured in the United States of America 1 2 3 4 5 6 BP 15 14 13 12 11 10 eISBN: 978-0-7613-8894-4
Contents
Gathering Information Take a deep breath through your nose.
Did you smell anything?
Maybe you smelled cookies baking. Or the scent of rain through an open window.
Freshly baked cookies smell delicious!
Smellingisoneofyourfivesenses. You use your nose to smell things.
Your sense of smell helps you learn about the world. It can also protect you from danger. Your sense of smell gives you lots of information about the world around you.
Most things release scent particles.
Most things release scent particles.
Scent particles are invisible chemicals that drift from an object and into the air.
When you breathe,
your nose takes in
scent particles.
Special nerves in your nose
change the particles into an
electrical signal. The signal is
sent to your brain.
Your brain tells you if the
smell is familiar and if
it is good or bad.
The powerful
smell of onions
makes some
people cry.
In the
Air
A scent is strong if you are
close to its source.
Food cooking on the stove
smells the strongest in the
kitchen.
Kitchens at dinnertime
often smell strongly
of food.
You can still
smell the food if
you are in your bedroom.
Thats because scents
travel in the air.
But the smell
wont be as
strong as it is
in the kitchen.
Good and
Bad Smells
People can identify thousands
of smells.
The human nose
detects a huge
variety of scents.
Some smells are nice. Others are awful. The smell of a cats litter box may make you want to hold your nose!
Rosessmellsweet.
A Matter of Opinion Sometimes people disagree about smells.
Your mom loves the smell of fresh coffee.
You may not.
Protection from Danger Your sense of smell can protect you from danger.
Yournosecantellyouifmilkhasgonesourorifmeathasspoiled.
Yournosecantellyouifmilkhasgonesourorifmeathasspoiled.
The rotten smell warns you not to eat the food. Sour milk can make you sick. Its smell lets you know that its not safe to drink.
The strong smell of smoke can let us know if theres a fire in a building.
It says that we
should leave right away
and get help.
Its best to leave a building if it smells of smoke.