son Science, 2-6 Boundary Row, London SEl 8HN, UK Thomson Science, 2-6 Boundary Row, London SEl 8HN, UK Thomson Science, 115 Fifth Avenue, New York NY 10003, USA Thomson Science, Suite 750, 400 Market Street, Philadelphia, PA 19106 Thomson Science, Pappelallee 3, 69469 Weinheim, Germany First edition 1998 c 1998 Thomson Science Thomson Science is a division of International Thomson Publishing I(TPG ypeset in pt Times by Doyle Graphics, Tullamore. Ireland at Britain by St Edmundsbury Press Ltd, Bury St Edmunds Suffolk BN0412720000 All rights reserved. No part of this publication may be reproduced, stored in a or transmitted in any form or by any means. rior written permission of the publishers. Applications for permission should be addressed to the rights manager at the London address of the publisher. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and nnot accept any legal responsibility or liability for any errors or omissions hat may be made A catalogue record for this book is available from the British Library Library of Congress Catalog Card Number: 97-77281 O Printed on acid-free text paper, manufactured in accordance with ANSI/ NISO Z39.48-1992( Permanence of PaperPublished by Blackie Academic & Professional, an imprint of Thomson Science, 2-6 Boundary Row, London SE1 SHN, UK Thomson Science, 2-6 Boundary Row, London SE18HN, UK Thomson Science, 115 Fifth Avenue, New York NY 10003, USA Thomson Science, Suite 750, 400 Market Street, Philadelphia, PA 19106, USA Thomson Science, Pappelallee 3, 69469 Weinheim, Germany First edition 1998 0 1998 Thomson Science Thomson Science is a division of International Thomson Publishing I@P* Typeset in 10/12pt Times by Doyle Graphics, Tullamore, Ireland Printed in Great Britain by St Edmundsbury Press Ltd, Bury St Edmunds, Suffolk ISBN 0 412 72000 0 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the publishers. Applications for permission should be addressed to the rights manager at the London address of the publisher. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made. A catalogue record for this book is available from the British Library Library of Congress Catalog Card Number: 97-77281 @ Printed on acid-free text paper, manufactured in accordance with ANSI/NISO 239.48-1992 (Permanence of Paper)