DISCUSSION OF RESULTS. 



133 



cite not only the opportunity for error in the determination of the gaseous 

 exchange in a preliminary period, but the fact that the pulse-rates, particularly 

 when the heart is beating rapidly, are difficult to count without photographic 

 registration. Finally, there may always be a difference of opinion regarding 

 the interpretation of the degree of activity shown by the curves. It is quite 

 possible that the attempt to classify the activity under six heads is a refinement 

 which the method will not warrant; unquestionably much less lack of agree- 

 ment would be found if but four or even three classifications were used. 



Observation with A. L., June 28, 1913. 



The curve in figure 45 gives a record of the muscular activity during an 

 observation made with A. L. This infant, who had at the time a body-weight 

 of 3.15 kilograms, was evidently very active and much more vigorous than 



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iNHHy 



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~r 



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A L. 



JUNE28.I9I3 



Fig. 45. Kymograph curve for A. L., June 28, 1913. 



J. V., as may be seen by the frequency and the amplitude of the vibrations 

 of the pointer on the kymograph. The activities ranged from II to VI, the 

 quietest part of the curve being that between 3 h 30 ra p. m. and 3 h 47 m p. m., 

 only two small movements near the end breaking the continuity of the line 



Table 26. — Comparison of the pulse-rate, metabolism, and muscular activity in observation 



with A. L„ June 28, 1913. 



'Preliminary period. 



which otherwise would have been characterized as I. Much greater variations 

 in the pulse-rate are to be found with this infant than with J. V., the records 

 ranging from 101 to 137 per minute (see table 26). The minimum pulse-rate 

 was obtained in the period from 3 h 30 m p. m. to 3 h 47 ra p. m., with an activity 

 of II and a heat-production of 247 calories per 24 hours. In the preliminary 

 period, when the activity was V,the pulse-rate was 118 and the heat-production 

 343 calories per 24 hours; the last two periods also show a high pulse-rate 

 and heat-production, with an activity of VI. Here again there is general 

 uniformity between activity, pulse-rate, and total heat-production. Although 



