The Elements of the Science of Nutrition
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\fpfft ' ' Columbia ^inibersfitr^ intljcCitpofi^etoPoiu Colkge of ^fjpgiciang anb ^urgeong 3^eference Itibrarp I Digitized by tlie Internet Arcliive in 2010 witli funding from Open Knowledge Commons (for the Medical Heritage Library project) http://www.archive.org/details/elementsofsciencOOIusk Thermometer Showing Comparison of Fahrenheit AND Centigrade Scales QONVENIENT COMPARISONS OF METRIC AND AvOXRDUPOIS WEIGHTS I kilogram = 2.2046 pounds I pound = 453-6 grams I ounce = 28.3 grams THE ELEMENTS OF THE SCIENCE OF NUTRITION BY GRAHAM LUSK. Ph.D., M.A.. F.R.S. (Edin.) PROFESSOR OF PHYSIOLOGY AT THE UNIVERSITY AND BELLEVUE HOSPITAL MEDICAL COLLEGE, NEW YORK CITY ILLUSTRA TED PHILADELPHIA AND LONDON W. B. SAUNDERS COMPANY 1906 Copyright, 1906, by W. B. Saunders Company PRESS OF SAUNDERS COMPANY PHILADELPHIA To Carl von Voit MASTER AND FRIEND FROM WHOM THE AUTHOR RECEIVED THE INSPIRATION OF HIS life's WORK THIS VOLUME IS DEDICATED. PREFACE. The aim of the present book is to review the scientific sub- stratum upon which rests the knowledge of nutrition both in health and in disease. Throughout, no statement has been made without endeavoring to give the proof that it is true. The widespread interest in the subject of nutrition at the present time leads the author to hope that this book may prove of value to the student of dietetics and to the chnical physician. Laboratory methods to explain the inner processes in dis- ease have been apphed to hospital patients for twenty years or more in Germany, but in the United States httle has been done in this regard. If such investigations are in any way promoted by their discussion here this writing will not have been in vain. On a previous occasion the author collected the more im- portant information concerning the Hfe history of the mineral constituents of the body for the American Text Book of Physi- ology, and the subject has been allotted Hmited space in this volume. The author would apologize to all whose claims of priority of discovery have not been duly recognized. He wishes to express his great obligation to a former pupil, Dr. Margaret B. Wilson, who has painstakingly corrected the manuscript. Graham Lusk. Physiological Laboratory, Uxr'ersity and Bellevue Hospital Medical College, New York, October i, 1906. 13 CONTENTS. CHAPTER I. Page. Introductory 17 CHAPTER n. The Feces 45 CHAPTER III. Starvation 52 CHAPTER IV. The Regulation of Temperature 78 CHAPTER V. The Influence of Proteid Food 98 CHAPTER VI. The Specific Dynamic Action of the Foodstuffs 133 CHAPTER VII. The Influence of the Ingestion of Fat and Carbohydrate 142 CHAPTER VIII. The Influence of Mechanical Work on Metabolism 160 CHAPTER IX. A Normal Diet 177 CHAPTER X. The Food Requirement Dltiing the Period of Growth 193 CHAPTER XI. Metabolism in Anemia, at High .A.ltitudes, in Myxedema and in EXOPHTH.A.LMIC Goiter 212 CHAPTER XII. Metabolism in Di.a.betes and in Phosphorus-Poisoning 225 CHAPTER XIII. Metabolism in Fever 249 CHAPTER XIV. PuRiN Metabolism.—Gout 270 CHAPTER XV. Theories of Met.a.bolism and General Review 288 Appendix 299 Index of Authors 309 Index of Subjects 317 IS THE ELEMENTS OF THE SCIENCE OF NUTRITION. CHAPTER I. INTRODUCTORY. The earliest scientific observations concerning nutrition were founded upon the commonly noted fact that in spite of large quantities of food eaten, a normal man did not vary greatly in size from year to year. It was understood early in the history of physiology that the weight added by the ingestion of food and drink was lost in the urine, the feces, and the "insensible per- spiration." The "insensible perspiration" was partly in evi- dence when moisture of the warm breath condensed upon a cold plate. By it was meant the usually invisible exhalations from the body, which are now known to be carbon dioxid and water. Sanctorius^ made many experiments upon himself and others to determine the amount of insensible perspiration. An old cut shows him sitting in a chair suspended from a large steel- yard. As a matter of routine he determined his own weight previous to each meal and then weighted the steelyard so as to counterbalance the additional food he proposed to eat. During the meal when the chair dipped he ended his repast. In Section I, Aphorism II, Sanctorius gives the following curious advice: "If a physician who has the care of another's health, is acquainted only with the sensible supplies and evacua- tions, and knows nothing of the waste that is daily made by the ^Sanctorius: "De medicina statica aphorisimi," Venice, 1614. Trans- lation by John Quincy, M.D., London, 1737. ' 2 17 l8 SCIENCE OF NUTRITION. insensible perspiration, he will only deceive his patient and never cure him." Aphorism III reads: "He only who knows how much and when the body does more or less insensibly per- spire, will be able to discern when or what is to be added or taken away either for the recovery or preservation of health." The modern era of the science of nutrition was opened by Lavoisier. The work of to-day is but the continuation of that done a century and more ago. Lavoisier and La Place made ex- periments on animal heat and respiration. The great German chemist Liebig derived his early training in Paris, residing there in 1822. Liebig's conception of the processes of nutrition fired the genius of Voit to the painstaking researches which laid the foundation of his Munich school. These have been repeated and extended by his pupils, of whom Rubner is chief, and by others the world over. Thus the knowledge often transmitted personally from the master to the pupil, to be in turn elaborated, had its seed in the intellect of Lavoisier. It was he who first discovered the true importance of oxygen gas, to which he gave its present name. He declared that life processes were those of oxidation, with the resulting elimination of heat. He believed that oxygen was the cause of the decomposition of a fluid brought to the lungs, and that hydrogen and carbon were produced in this fluid and then united with oxygen to form water and carbon dioxid. It was he wlio first made respiration experiments on man, the results of which are briefly described in a letter to ISIonsieur Terray,^ written in Paris and dated November 19, 1 790. There is no existing record of the apparatus with which Lavoisier worked and early obtained accurate results. The more important conclusions Lavoisier sums up as follows: 1. The quantity of oxygen absorbed by a resting man at a temperature of 26° C. is 1200 pouces de France"^ 'howxXy. 2° 2. The quantity of oxygen required at a temperature of 1 C. rises to 1400 pouces. ' Report of the British Association for the Advancement of Science, Edinburgh, 1871, p. 189. ' I cubic pouce—0.0198 liters. INTRODUCTORY. 19 3. During the digestion of food the quantity of oxygen amounts to from 1800 to 1900 pouces. 4. During exercise 4000 pouces and over may be the quantity of oxygen absorbed. These remarkable results are in strict accord with the knowledge of our own day. We know more details, but the fundamental fact that the quantity of oxygen absorbed and of carbon dioxid excreted depends primarily on (i) food, (2) work, and (3) temperature, was estabhshed by Lavoisier within a few years after his discovery that oxygen supported combustion. It was, however, quickly noted that if carbon and hydrogen burned in the lungs, the greatest heat would be developed there, a result not in accordance with observation. It was then sug- gested that the blood dissolved oxygen, and that the production of carbon dioxid and water took place through oxidation within the blood. In 1837 Magnus discovered that the blood did hold large quantities of oxygen and carbon dioxid, which gave apparent support to this theory. Ludwig in his later years believed that the oxidation took place in the blood. ^ Through the critical studies of Liebig, which were pubHshed in 1842, it was seen that it was not carbon and hydrogen which burned in the body, but proteid, carbohydrates, and fat. Liebig's original theory was that while oxygen caused the combustion of fat and carbo- hydrates, the breaking down of proteid was caused by muscle work. It will be shown later that oxygen is not the cause of the decomposition of materials in the body, but that this decom- position proceeds from unkno\Mi causes, and the products involved unite with oxygen. These chemical changes of mate- rials under the influence of Hving cells is known as metabolism. This process may involve two factors, cataholism, or the reduction of higher chemical compounds into lower, and anabolism, or the construction of higher substances from lower ones. Liebig was also the father of the modern methods of organic analysis, and with him began the great accumulation of knowl- edge concerning the chemistry of the carbon compounds, in- 1 Verbal statement to the writer. 20 SCIENCE OF NUTRITION. eluding the many products of the animal economy. These dis- coveries gave the vi^orld a knowledge of the constitution of foods, of urine, of feces, and of tissues, which was not possessed by Lavoisier. Liebig apphed to the problems of biology the mental wealth of the newer chemistry which he himself was creating. He knew that proteid contained nitrogen, and in 1842 he suggested that the nitrogen in the urine might be made a measure of the proteid destruction in the body.^ The proof that such was the case was afforded by Carl v. Voit,^ who established the fact that an animal could be brought into what he called nitrogenous equihbrium.