Food in Relation to Work. 137 
resulting from complete oxidation would be above that 
from mere destruction within the body. The composition 
of the remaining product being, however, known, a cor- 
rection can be made in the experimental figures, and 
an approximately correct expression obtained for the 
units of heat generated by the combustion within the 
body of a given weight of muscular tissue. 
Applying these data to the observations of Messrs. 
FlCK and WlSLlCENUS the work-value of the nitrogen 
eliminated is easily calculated, on the supposition that 
this nitrogen represents so much destroyed tissue. The 
other side of the question, viz., the amount of work 
actually done, is simply the weights of the two observers 
raised to the height to which they ascended ; and, as in 
the case of the work-value of the tissue substance, is 
readily expressed in foot-pounds. 
Proceeding thus, it was found that the work equivalent 
to the eliminated nitrogen, on the supposition that the 
nitrogen was yielded by the destruction of muscular 
tissue, formed but a small fraction of that actually 
performed. 
Numerous observers have repeated the above experi- 
ments with various modifications. The most notable of 
these was Parkes, who, in observations conducted on 
soldiers, confirmed in the main the results of FlCK and 
Wislicenus. Dr. Austin Flint, it is true, who adopted 
for his subject of experiment a celebrated American 
pedestrian, WESTON, arrived at somewhat different con- 
clusions, but the figures yielded in his observations 
admitted of being interpreted both ways ; and a subse- 
quent series of investigations by PAW on the same 
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