402 E. Frankland on the Source of Muscular Power. 
It is evident that the above determination of the actual energy 
developed by the combustion of muscle in oxygen represents 
more than the amount of actual energy produced by the oxyda- 
tion of muscle within the body, because, when muscle burns in 
oxygen its carbon is converted into carbonic acid, and its hydro- 
gen into water; the nitrogen being, to a great extent, evolved 
in the elementary state; whereas, when muscle is most com- 
pletely consumed in the body, the products are carbonic acid, 
water and urea; the whole of the nitrogen passes out of the 
body as urea—a substance which still retains a considerable 
amount of potential energy. Dry muscle and pure albumen 
yield, under these circumstances, almost exactly one-third of 
their weight of urea, and this fact, together with the above de- 
of urea, enables us to deduce with certainty the amount of ac- 
tual energy developed by muscle and albumen respectively when 
consumed in the human body. It is as follows:— 
Actual energy developed by one gram of each substance when consumed in the body. 
Ni f subst: . ted at 100° 4 Heat units. of f ha ‘ 
‘ame 0: C. (Mean.) iieus 
Beef muscle puritied by ether, | 4368 1848 
Purified albumen, ........... 42638 1803 
We have thus ascertained the first of our three data, viz., the 
amount of force or actual energy generated by the oxydation of 
a given amount of muscle in the body; and we now proceed to 
ascertain the second, viz., the amount of mechanical force ex- 
erted by the muscles of the body during a given time. For this 
purpose we have only to avail ourselves of the details of Fick 
viz., the height of the summit of the Faulhorn above the level 
of the lake of Brienz multiplied by the weight of the body; 
the former reckoned in meters, the latter in kilograms. The 
weight of the body with the equipments (hat, clothes, stick) 
" Phil. Mag., vol. xxxi, p. 496, 1866.- 
