INTRODUCTION. 



The number of investigators in the total metabolism of matter and 

 transformations of energy in man, animals, and plants is rapidly 

 increasing, as well as the number of individuals (principally clini- 

 cians) who are making practical applications of the methods used and 

 the results obtained in these fields. The apparatus used and the 

 methods of calculation applied necessitate frequently the use of 

 tables and conversion factors. The tables most used are those in 

 connection with the measurements of respiratory exchange, the 

 reduction of gas volumes to standard conditions, computation of heat, 

 and the standards of normal metabolism. At present these are 

 published in various places and no adequate compilation of them 

 exists. 



The purpose of this publication is to make available to investi- 

 gators the majority of tables and conversion factors needed in cal- 

 culations of results from measurements obtained by the several types 

 of respiratory exchange apparatus, particularly the Regnault-Reiset 

 and the combination of spirometer, valves, and breathing appliance, 

 and to make available the standards of normal metabolism. 



The method of presentation is as follows: A section giving the 

 method of construction and calculation of the tables and their appli- 

 cation is followed by the section giving the tables themselves. The 

 last part gives formulas and conversion factors which may be of use. 



The tables and factors have been collected from various sources 

 and principally from Smithsonian Physical Tables, 1896, 1920; Smith- 

 sonian Geographical Tables, 1918; Landolt-Bornstein Physikalisch- 

 chemische Tabellen, 1905; Jeleniks Psychrometer-Tafeln, 1911; 

 articles published in the Archives of Internal Medicine by workers of 

 the Russell Sage Institute of Pathology and the Cornell Medical 

 School; publications of the Carnegie Institution of Washington; 

 Armsby's Principles of Animal Nutrition, 1906; and Joslin's Treat- 

 ment of Diabetes Mellitus, 1917. Some of the tables have been 

 computed by the staff of the Nutrition Laboratory. 



This publication was prepared at the suggestion of Professor 

 Francis G. Benedict, whose advice in the selection and ranges of the 

 tables has been very helpful. 



The calculation and preparation of the majority of the tables 

 have been under the supervision of Mr. W. H. Leslie and their accu- 

 racy is due to his painstaking care. He was assisted by Miss 

 Clara E. Borden, Miss Mary D. Finn, and Mrs. F. N. Horton. He 



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