392 INFLUENCE OF MUSCULAR EXERCISE ON THE URINE. [BOOK I. 



Therefore that of the gram of albumin was assumed to be 



6730 grm. -degrees. 



Hence the heat of combustion of the decomposed albumin amounted, 

 In Fick to (37-17 x 6730) or about 250000 grm.-degrees. 

 In Wislicenus to (37 x 6730) or about 249000 grm.-degrees. 

 This converted into mechanical equivalents of that day, gave 

 For Fick, 106250 kilog. -metres. 

 For Wislicenus, 10"3825 kilog.-metres. 



What Fick and Wislicenus' experiments shew beyond all doubt 

 is, that during and after muscular contraction no quantity of effete 

 nitrogenous material passes out of the body which is at all adequate 

 to the mechanical work done in contraction. What they do not shew 

 is whether or not any nitrogenous waste occurs in muscle during 

 activity. 



It will have been observed that the experiments of Fick and 

 Wislicenus do not afford a comparison of the same organism during 

 repose and during activity, while all the other conditions are rigorously 

 the same. It is true that the food during the period immediately 

 before and immediately after exercise was non -nitrogenous, and so far 

 identical with that of the time of exercise itself. Nevertheless the 

 experimenters were not under precisely similar conditions in the three 

 periods named, because these periods were not equally remote from 

 the last ingestion of nitrogenous food. When the supply of nitro- 

 genous food is suddenly stopped, it is well known that the excretion 

 of nitrogen sinks to the starvation-standard with diminishing velocity. 

 Unless we make ourselves acquainted with the rate of this descent, 

 we cannot estimate the effect upon the excretion of nitrogen of other 

 circumstances or conditions. 



Expert- In order to furnish such a comparison, and at the 



merits of same time to control the observations of Fick and 



E. A. Parkes. Wislicenus, Parkes 1 undertook some experiments upon 

 soldiers at the Victoria Hospital, Netley. Two sets of experiments 

 were carried on. In one, work and repose were contrasted, in respect 

 of their influence upon nitrogenous excreta, on an unrestricted diet 

 containing no nitrogen ; and in the other, on a normal diet including 

 nitrogen, which was maintained practically constant during the whole 

 time of the experiment. We will confine ourselves in the first 

 instance to the experiments with a non-nitrogenous diet. 



I. The two soldiers were kept for four days at light em- 

 ployment, with a normal temperate diet including meat, bread, 

 ale, etc. 



> II. During two days they were put on a non-nitrogenous diet of 

 arrow-root, suga/and fat, and kept in perfect repose. 



1 E. A. Parkes, " On the Elimination of Nitrogen during Kest and Exercise." Proceed. 

 Roy. Soc. Lond., Vol. xv. p. 339; Vol. xvi. p. 44, 1867. 



