174 COMPARISONS OF RESPIRATORY EXCHANGE. 



This precaution was necessary, as this particular subject had a tendency to 

 fall asleep during an experiment; the mouth would then relax, with consequent 

 danger of leakage of air. In first period with mouthpiece, subject asleep at 

 beginning and drowsy throughout period; similar conditions in second period 

 with nosepieces; in third period with nosepieces, more awake and moved arms; 

 as a rule somewhat more awake in periods with mouthpiece, owing to discom- 

 fort caused by mouthpiece and noseclip. Subject preferred nosepieces to 

 mouthpiece. Respiration-rate fairly regular in all but second period with 

 mouthpiece. 



F. G. B., November 11, 1910. Nosepieces, 4 periods; mouthpiece, 4 periods; 

 preliminarjr period, about 1 hour 33 minutes; periods with nosepieces and 

 mouthpiece in series. Respiration-rate secured by means of side outlet in 

 three-way valve. Subject urinated after first period. At end of second 

 period, subject stated that his neck was in a strained position but that rest of 

 body was relaxed. Also said that air seemed dry; water was therefore added 

 to moistener. With mouthpiece was troubled with saliva and found noseclip 

 uncomfortable after first 5 minutes. Noticed a vibration of air with the 

 mouthpiece at first but soon became accustomed to it. Pulse- and respiration- 

 rates uniform. 



T. M. C., November 14, 1910. Nosepieces, 7 periods; mouthpiece, 3 periods; 

 preliminary period, 15 minutes; periods with nosepieces and mouthpiece 

 in series. Respiration-rate secured by means of side outlet in three-way 

 valve. Elastic bandage, about 5 cm. wide, used over mouth in first, second, 

 fourth, and fifth periods with nosepieces in the hope of finding some method of 

 insuring a perfect closure of the mouth. Subject stated that bandage was 

 somewhat uncomfortable, particularly in first part of period, and that probably 

 most men, after once using the bandage, would have learned to keep the mouth 

 closed without the necessity of resorting to such a method as this. The 

 kymograph record of the respiration showed a tendency, during the mouth- 

 piece periods, for slightly wider excursions ; in the middle of the last period with 

 the mouthpiece there were a number of very wide excursions, indicating a 

 pressure on the tension equalizer. Pulse-rate was regular throughout the 

 experiment. 



H. F. T., June 27, 1911. Nosepieces, 4 periods; mouthpiece, 3 periods; 

 periods with nosepieces and mouthpiece in series. Subject stated that he 

 experienced no discomfort in breathing by either method, but that there was a 

 tendency for the saliva to increase with the mouthpiece. Pulse- and respira- 

 tion-rates regular. 



H. F. T., September 8, 1911. Nosepieces, 3 periods; mouthpiece, 4 periods; 

 preliminary period, 41 minutes; periods with nosepieces and mouthpiece in 

 series. Pulse-rate regular. 



H. F. T., September 9, 1911. Mouthpiece, 4 periods; nosepieces, 3 periods; 

 preliminary period, 35 minutes; periods with mouthpiece and nosepieces in 

 series. During the last two periods with the nosepieces, the sub j ect had a great 

 desire to urinate but on the whole was quiet throughout the series. Pulse- 

 and respiration-rates uniform. 



K.H.A., September 23, 1911. Nosepieces, 4 periods; mouthpiece, 4 periods; 

 periods w r ith nosepieces and mouthpiece in series. Pulse-rate very even. In 

 all of the periods there was a very distinct tendency, shown at the beginning, 

 for the subject to breathe slowly and regularly. This was in all probability 

 due to his anticipation of the turning of the three-way valve connecting him 

 with the circulating air of the apparatus; respiration-rate otherwise regular. 



K. H. A., September 28, 1911. Nosepieces, 3 periods; mouthpiece, 3 periods; 

 periods with nosepieces and mouthpiece in series. Pulse-rate fairly uniform 

 in individual periods. Respiration-rate comparatively uniform throughout 

 experiment. 



