INTRODUCTION. 



17 



The respiratory quotients all seem unusually high, and this fact throws 

 doubt upon the accuracy of the research. It is probable, however, 

 that the carbon-dioxide determinations are well within the limits of 

 accuracy, as is usual with methods of this type. From the protocols 

 of one of Poppi's studies it appears that the experiments were each 2 

 hours long, but no estimations are given regarding the muscular activity 

 or the pulse-rate. 



In 1904 Rubner and Heubner 1 reported another series of experiments 

 covering a period of 5 days. The subject was a breast-fed infant, 5| 

 months old and weighing 9.7 kilograms. Notwithstanding the appar- 

 ently large changes in the activity from day to day, the investigators 

 found that the carbon-dioxide output on the last 4 days was fairly 

 constant — a fact which puzzled the authors, who suggest a compensa- 

 tory influence in the life of the infant. They compare the results found 

 in this observation with those secured with other infants in the previous 

 work done by them, and find an increase in the carbon-dioxide output 

 of 21 per cent over the results obtained with the breast-fed infant 

 previously studied. (See table 6.) This increase they explain by saying 

 that it is due to the greater activity of the infant in the last experiment. 



Table 6. — Metabolism of infants compared (Rubner and Heubner). 



Subjects and diet. 



Atrophic child (cow milk) 



Breast child 



Child (cow milk) 



Child (breast, of this experiment) 



Body- 

 weight. 



kilos. 



3 



5 



8 



10 



Calories per 



square meter of 



body-surface 



per day. 



1,090 

 1,006 

 1,143 

 1,219 



In 1908 a report appeared of the first in a remarkable series of experi- 

 ments carried out by Schlossmann and Murschhauser in Dusseldorf. 2 

 The protocols of this experiment were given in connection with a 

 description of the testing of the modified Regnault-Reiset apparatus 

 constructed by Zuntz and Oppenheimer. The authors, Schlossmann, 

 Oppenheimer, and Murschhauser, emphasize the importance of obser- 

 vations when the infant is asleep ; they accordingly preferred to make 

 their observations the first half of the night, feeding the infant with a 

 large amount of breast milk in the early evening. The measurements 

 of the metabolism of the infant during this experiment are given in 

 table 7. During the experimental period the infant weighed 5.79 kilo- 

 grams, the calculated body-surface being 0.384 square meter (using 

 Meeh's formula given on page 15). 



Rubner and Heubner, Zeitschr. f. exp. Path. u. Therapie, 1904-05, 1, p. 1. 

 Schlossmann, Oppenheimer, and Murschhauser, Biochem. Zeitschr., 1908, 14, p. 385. 



