First Edition, August, 1923
Second Edition, December, 1925
Third Edition, January, 1930
Fourth Edition, March, 1934
Preprint of pages ix + 79 of Fifth Edition, October, 1938
Fifth Edition, April, 1939
Sixth Edition, January, 1948
Seventh Edition, October, 1957
COPYRIGHT ©, 1957
The Williams & Wilkins Company
Made in United States of America
Library of Congress
Catalog Card Number
57-11183
COMPOSED AND PRINTED AT THE
WAVERLY PRESS, INC.
Mt. Royal and Guilford Aves.
Baltimore 2, Md., U. S. A.