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



The alternation of light labour, with repose or long marches, was 

 conducted as in the first experiment, viz. : 



I. Four days of ordinary occupation. 



II. Two days of perfect repose. 



III. Four days of ordinary occupation. 



IV. Two days of hard marching. 



V. Four days of ordinary occupation. 



Again we may take the case of one of the soldiers observed, viz. the 

 one whose data served us in the first experiment. 



COMPARISON OF TOTAL EXCRETION OF NITROGEN DURING REST AND 

 HARD LABOUR, IN GRMS. 



The above table shews us that there is a slight increase in the total 

 amount of nitrogen excreted during labour as compared with a time of 

 perfect repose. This agrees with the facts elicited during the first set 

 of experiments. But it further appears that during the first 36 hours 

 of the period of labour the excretion of nitrogen is actually less than 

 during the corresponding period of rest. This fact is not indeed 

 supported by the data from the same man in the former experiment 

 when the diet was non-nitrogenous; but in the case of his fellow 

 in the previous experiment, the excretion of nitrogen passed through 

 the same phases ; that is to say, in the case of the other soldier on a 

 non-nitrogenous diet just as in the case of this one on a diet including 

 nitrogen, the immediate effect of hard muscular exercise was to diminish 

 the excretion of nitrogen : it is not until the night of the second 24 

 hours that we observe such an out-pouring of nitrogen as to raise the total 

 excretion of the two days of labour above that of the two days of rest. 

 This curious circumstance of the elimination of nitrogen will at once 

 remind us of the case of Fick and Wislicenus, in both of whom, on 

 a non-nitrogenous diet, muscular exercise seemed at first to diminish 

 the excretion of nitrogen. 



If the above table be compared with the following one shewing 

 the nitrogenous excretions in the four days preceding rest, in the four 

 days following rest and preceding work, and in the four days following 

 work, a very interesting contrast will arise. 



