OBSERVATIONS BY HASSELBALCH. 17 



required for the absorption and oxidation of the three nutrients in the 

 food the protein, fat, and carbohydrate. 



The only complete respiration experiments on new-born infants 

 known to me were undertaken first at Prague under the direction of 

 Mares by Scherer 1 and Babdk. 2 The experiments of Babak on the respi- 

 ratory exchange are only a link in the investigation of the new-born 

 infant's heat regulation. The surprising result of both these investi- 

 gators' experiments is this, that not only after birth, but even with 

 infants several weeks old, an unusually low respiratory quotient was 

 found. Scherer reports 55 summer experiments with respiratory 

 quotients ranging from 0.567 to 0.898; in 27 instances the quotients 

 are under 0.70, a quotient which, for the grown individual, is the lowest 

 imaginable, at least for rather long periods of time. His 30 winter 

 experiments show but one quotient over 0.70; the lowest is 0.493, the 

 highest 0.717. Babak's experiments generally show a higher quotient, 

 but 0.51 is not uncommon with him. 



To explain these low quotients, which are ordinarily found only with 

 hibernating animals, Scherer has to resort to the explanation generally 

 assumed for these animals, i. e., an incomplete burning of food material, 

 whereby the oxygen taken in does not leave the organism in its entirety 

 as carbon dioxide, but to some extent is stored up in the form of unstable 

 compounds. Scherer, in attempting to explain the significance of this 

 saving of oxygen in infancy, refers to the "excess of anabolism over 

 katabolism"; but this conclusion does not hold true. In the fetal life, 

 then, one must also expect low quotients, lower than with the free oxi- 

 dation of the embryo's food material. But the chicken embryo burns 

 fat and has a fat quotient, 0.71; the guinea-pig embryo has a carbo- 

 hydrate quotient 3 of 1.00. The snake embryo has a mixed quotient, 

 about 0.85, while with the silk-worm embryo 4 the respiration takes 

 place with a diminution of both fat and carbohydrate, which naturally 

 would result in a quotient between 0.7 and 1.0. 



The hypothesis presented by Farkas, 5 partly in reference to the fat 

 quotient with the bird embryo and partly in reference to Scherer's and 

 Babak's low quotients with new-born infants, "wahrend der embryo- 

 nalen Entwicklung und in den ersten Stunden des Lebens iiberwiegend 

 Fett verbrannt wird," may be disputed. The different animal classes 

 can not be expected to nourish their embryos with the same material; 

 that they do not do this has already been mentioned, and Farkas him- 

 self brings forward a new example to demonstrate this point. 



In view of the doubtful respiratory quotients found by Scherer and 

 Babak, we must reject in advance Scherer's second conclusion concern- 

 ing the amount of the respiratory exchange. Eighty-five experiments 

 are mentioned, not with the same child, but with different children at 

 different times. From this material, without taking into consideration 

 the child's condition during the experiment, such as movements, crying, 



Scherer, Jahrb. f. Kinderheilk., 1896, N. F., 43, p. 471. 



2 Babak, Archiv f. d. ges. Physiol., 1902, 89, p. 154. 



3 Bohr, Vidensk. Selsk. Forh., 1900. 



4 Farkas, Archiv f. d. ges. Physiol., 1903, 98, p. 490. 6 Farkas, loc. cit., p. 517. 



