INFLUENCE OF MUSCULAR EXERTION UPON METABOLISM. 199 
corresponding increase in the urinary nitrogen (compare Chapter 
V), but this was small compared with the much greater amount of 
work performed. Moreover, it did not, as in the first series of 
experiments, augment from day to day during the period of severe 
work. The following table shows the principal results of this 
series, the figures for urinary nitrogen and for live weight being 
given for the first and second halves of each period: 
Nitrogen. ‘3 
Period. York, Weight, 
Digested, In Urine, Kg. 
Grms. Grms. 
158.9 560.3 
Brace ce tedlpsinksuba ida 810,000 | 173.6 | aed ie 
MIO hs yi cans cates 2,430,000 | 178.8 { nies ae 
166.4 5425 
Tata seatacoalanta beanie: 810,000 | 178.8 | vee Pree 
Series IV.—Upon the basis of the foregoing facts Kellner deter- 
mined the maximum amount of work which his horse could perform 
on a fixed medium ration without causing an increase in the proteid 
metabolism. One kilogram of starch was then added to the ration 
and the maximum amount of work that could be performed upon 
this new ration without causing such an increase was determined. 
In the nature of the case this determination could not be of the 
highest accuracy, but it is amply sufficient for our present purpose. 
The principal results are given in the following table, the amount 
of work being expressed by the number of revolutions of the dyna- 
mometer, since relative results are all that are required: 
Nitrogen. li 
ive 
Period. Work, Weight, 
Digested, In Urine, Kg. 
Grms. Grms. 
Tf veuucont: 300 |) 107.2 540.0 
rE peas : 600 | | 110.2 : 
Hh. ep Cithent 600 |$ 121.1 115.6 | 533.1 
TE sscuce snare 500 109.4 | 582.5 
iE Rees, 400 109.6 | 530.7 
ae Aneee With 800° 115.5 | 517.1 
Tease ee t starch. t 600 t 120)4 | 109.6 | 515.4 
