EARLIER RESEARCHES WITH NEW-BORN INFANTS. 13 



to secure information from Mensi regarding the apparatus and the 

 technique used in the observations. The infant was placed under a 

 bell in which air was circulated. The carbon-dioxide output was deter- 

 mined by barium hydroxide, while the oxygen consumption was found 

 by measuring the amount used from a flask of known capacity in replac- 

 ing the oxygen consumed by the infant. The principle of the apparatus 

 appears to be essentially that of Regnault and Reiset. 



OBSERVATIONS BY SCHERER. 



Perhaps no research on the gaseous metabolism of infants is more 

 frequently cited as being the earliest and of the greatest significance 

 than is that of Scherer 1 in the laboratory of Professor Mares in Prague. 

 As pointed out in our earlier consideration of these experiments, 2 the 

 extraordinarily low respiratory quotients found by the investigator 

 lead one to doubt the accuracy of the determination of the gaseous 

 metabolism. In the latter part of his article, Scherer discusses the 

 protocols of one experiment, which he gives in detail, and points out 

 the fact that Mares considered that the increase in the nitrogen of 

 the air inside the chamber should be taken as an indication of the accu- 

 racy of the experiment, since the smaller the nitrogen accumulation, 

 the more accurate is the experiment. 



Unusual attention was paid in the Prague laboratory to the possi- 

 bilities of leaks into or out of the respiration system, and the earlier 

 work in Pfltiger's laboratory was keenly criticized by Mares 3 in the 

 original description of his apparatus for studying the metabolism of 

 animals during hibernation. In this Bohemian monograph Mares 

 devotes several pages to a discussion of the possibilities of error due 

 to leaks, to the accumulation of nitrogen, and to the role the nitrogen 

 may play in the total metabolism, and gives a number of arguments 

 for and against the belief that free nitrogen rises from protein disin- 

 tegration. It is surprising, therefore, to find that Scherer assumed 

 the percentage composition of the compressed oxygen used by him 

 to be that determined by an old analysis. This point can best be 

 considered in connection with the keen criticism of Scherer's experi- 

 ments by Hasselbalch in the excellent paper which will be presented 

 somewhat later in this report. 



Scherer made 55 experiments in the spring and summer and 30 

 experiments in the winter, each experiment being about 2 hours long. 

 A considerable number of these experiments were with infants 7 days 

 old or under, namely, 24 experiments in the summer and 7 experiments 

 in the winter. It is most unfortunate that at this period in the develop- 

 ment of the respiration apparatus in the Prague laboratory control 



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



Benedict and Talbot, Carnegie Inst. Wash. Pub. No. 201, 1914, p. 14. 



3 Mares, Arch, bohemes de med., 1889, 2, p. 458. 



