100 EUGENE F. DU BOIS 



Coleman and Du Bois . have estimated the total metabolism of 

 their typhoid patients studied in the calorimeter by adding to the basal 

 figures 10 per cent for muscular activity and 3 per cent for the specific 

 dynamic action of food. During the febrile periods the estimates fall 

 between 1,700 and 2,600 calories per day, and these figures may be con- 

 sidered a fair average for the general run of typhoid patients. If we 

 want to make an exact estimate in any individual case it is necessary to 

 determine his respiratory exchanges but we can probably come within 5 to 

 20 per cent by the following process: First determine the surface area 

 and multiply by the normal figure for a person of that age and sex. This 

 will give his normal basal calories. Next add the percentage increase 

 caused by the particular period of the disease as shown in Table 1 and 

 add a suitable percentage to cover the muscular activity. This latter will 

 range from 10 per cent for a quiet subject to 50 per cent for a man 

 who is delirious. There are little exact data on the effect of restlessness 

 on the heat production in fever, but in a few cases which have been 

 observed while delirious the figures are not much higher than similar 

 patients at rest. 



Direct and Indirect Calorimetry. Before it was possible to study 

 fever patients in a respiration calorimeter a number of investigators were 

 inclined to believe that there was some abnormal process of metabolism in 

 disease which interfered with the proper oxidation of proteins, fats or 

 carbohydrates in such a manner that there was an error in the method 

 of calculating the heat production from the respiratory exchanges. 

 This point was raised by those who obtained bizarre results through 

 unsuspected errors in technic. Rather than admit that anything 1 

 could be wrong with the experiments they attacked the validity of the 

 ordinary laws of metabolism and even the law of the conservation of 

 energy. 



Fortunately the calorimeter has been able to prove that there is no 

 such profound qualitative change in the metabolism in fever. It has 

 measured the heat production by the method of direct calorimetry which 

 determines by physical means the calories of radiation, conduction, 

 vaporization and the storage of heat in the body. At the same time it 

 measures the heat production by the method of indirect calorimetry which 

 uses chemical methods to determine the grams of protein, fat and carbo- 

 hydrate oxidized and calculates the calories by using the standard heat 

 values for these food-stuffs. Coleman and Du Bois in typhoid fever and 

 convalescence measured in all experiments by the direct method 12,540 

 calories, by the indirect method 12,822 calories, a difference of only 

 2.2 per cent. In the febrile experiments, excluding; the first periods the 

 direct method gave 5,584 calories, the indirect 5,720. These differences 

 are as small as can be expected when experimental periods of only three 



