1883.] Bodily Labour upon the Discharge of Nitrogen. 17 



I have further been able to show as the result of a very lengthy 

 experiment in which several days of complete abstinence from food 

 were introduced, and of which it is impossible in a short abstract to 

 give the figures, that just as in Dr. Parkes' experiment on the effect 

 of privation of nitrogenous food the diminution of the nitrogen 

 stored in the system was followed by retention, i.e., by a state of 

 things in which the intake was greater than the output, so, after the 

 disturbance of the nutrition of the body which is produced by severe 

 labour, the immediate effect of which is to diminish the store of 

 nitrogenous material in the system, there follows a corresponding 

 diminution of discharge ; so that the result is the same, viz., to use 

 Dr. Parkes' own words " an insufficient supply at one time must be 

 subsequently compensated " whether the insufficiency be clue to privation 

 of food or to exercise. 



A third result of importance is this : that this storage of nitrogen 

 is the expression of a tendency of the organism to economise its 

 resources, which is much more constantly operative than has hitherto 

 been supposed. 



Finally, as regards the phosphates and sulphates, it has been shown 

 that unless the exertion be very severe the phosphates are not increased, 

 whilst the output of sulphates is distinctly increased in every case, 

 the increase being in general terms proportional to that of nitrogenous 

 material. 



It is a matter of regret that the total sulphur of the food was not 

 estimated ; it is known that the percentage of sulphates contained in 

 the food was insignificant as compared with that excreted in the urine, 

 .and consequently almost all the discharge must have been a product 

 of oxidation. 



I beg leave in conclusion, to state that the expenses of the present- 

 research, which have been extremely heavy, have been defrayed by a 

 grant of the British Medical Association. I desire to express to the 

 Association my most grateful thanks. 



vol. xxxvi. 



c 



