Published by Charles C Thomas 

 301-327 East Lawrence Avenue, Springfield, Illinois 



Published simultaneously in Canada by 

 The Ryerson Press, Toronto 



All rights in this book are reserved. No part may be repro- 

 duced in any form w^hatsoever without permission in writing 

 from the publisher, except by a reviewer who wishes to quote 

 extremely brief passages in connection with a critical review. 

 Reproduction in whole or in part in digests, in condensations 

 of the literature, in lectures, or in films; or by multigraphing, 

 lithoprinting, or by any other processes or devices, is reserved 

 by the publisher. For information, address Charles C Thomas. 



Copyright, 19^6, by Charles C Thomas 



First Edition, January 1931 

 Second Edition, September 1939 



Third Edition, January 1946 



Printed in the United States of America 



