[Transcriber's notes: The text of this e-book has been preserved in its original form apart from correction of the typographic errors listed below. Illustrations have been repositioned adjacent to relevant tabulated data, and the List of Illustrations adjusted accordingly. On p.72 an image of the Xanthin formula incorrectly shows a double bond between a carbon and nitrogen atom – the correct formula is shown on the next page – and there is a date discrepancy on p. 248 between the text and the illustration caption (November 18/February 27). Footnotes have been repositioned below the relevant paragraphs. Typographic corrections: enyzmes → enzymes oxgyen → oxygen enyzme → enzyme Futher → Further mechancial → mechanical rythmical → rhythmical economcially → economically circulirinden → circulirenden SUBJECT → SUBJECTS equibrium → equilibrium availibility → availability (166) grams → (166 grams) accusstomed → accustomed Glassner → Glässner strach → starch ] THE NUTRITION OF MAN THE NUTRITION OF MAN BY RUSSELL H. CHITTENDEN, Ph.D., LL.D., Sc.D. AUTHOR OF “PHYSIOLOGICAL ECONOMY IN NUTRITION,” ETC. PROFESSOR OF PHYSIOLOGICAL CHEMISTRY AND DIRECTOR OF THE SHEFFIELD SCIENTIFIC SCHOOL OF YALE UNIVERSITY WITH ILLUSTRATIONS NEW YORK FREDERICK A. STOKES COMPANY PUBLISHERS _Copyright, 1907_, BY FREDERICK A. STOKES COMPANY _All rights reserved_ May, 1907 _FIFTH PRINTING_ PREFACE The present book is the outcome of a course of eight lectures delivered before the Lowell Institute of Boston in the early part of 1907. In this presentation of the subject the attempt has been made to give a systematic account of our knowledge regarding some of the more important processes of nutrition, with special reference to the needs of the body for food. In doing this, the facts accumulated by painstaking observations and experiments during recent years in our laboratory have been incorporated with data from other sources and brought into harmony, so far as possible, with the modern trend of physiological thought. Numerous experimental results, hitherto unpublished, have been introduced, notably in Chapter VII, in which a few of the data recently obtained in our laboratory with dogs are presented in some detail, since they afford evidence of the error of the current arguments concerning the necessity of a high proteid intake by man, as based on the results of earlier investigators with high proteid animals. It is hoped that the facts and arguments here presented will help to arouse a more general interest in the subject of human nutrition, as right methods of living promise so much for the health and happiness of the individual and of the community. CONTENTS CHAPTER I PAGE FOODS AND THEIR DIGESTION 1