INFLUENCE OF BODILY EXERCISE ON THE ELIMINATION OF NITBOGEN. 269 



Report of the Committee, consisting of Dr. Pye-Smith, Dr. M. 

 Foster, and Dr. Burdon Sanderson, appointed for the pu7pose 

 of investigating the Influence of Bodily Exercise on the Elimina- 

 tion of Nitrogen {the experiments conducted by Mr. North). 



In presenting an account of the expenditure of the grant of 501. made 

 to us last year for the purpose of investigating the effect of muscular 

 labour on the elimination of nitrogen, we beg to submit the following 

 statement of the present position of tlie inquiry. 



The subject naturally divides itself into two parts — (1) The analysis 

 of the ingesta and excreta, and (2) the work. The experiments under 

 the former head have been carried out with funds derived from another 

 source, and have arrived at a point at which it becomes desirable to 

 employ some means by which the relative amount of work done at 

 diffei'ent times can be compared with the utmost practicable exactitude. 



The grant has been expended in providing a machine for this purpose, 

 and for certain accessories. 



The machine consists essentially of an arrangement by which a 

 weight — the amount of which can be regulated — may be raised through 

 a known distance and then allowed to fall to its position of rest. 



Without entering into a detailed account of the apparatus it will 

 suffice here to describe the arrangement by which the muscular recoil at 

 the end of the stroke is got rid of. 



As will be seen in the accompanying photographs,' the force is exerted, 

 not directly upon the weight, but upon a cam keyed on to the same axis 

 as the pulley which carries the weight. By means of this cam the work 

 at the end of the stroke rapidly diminishes to practically nothing, and in 

 consequence there is no muscular recoil. The handle by which the weight 

 is raised carries an automatic clutch so arranged that, when the weight 

 has been raised to a certain point, it is released. The descent of the 

 handle by its own weight causes the clutch to part an eye on the end of 

 the rope attached to the cam, and the operation can then be repeated. 

 The apparatus has been so constructed that the work can be done in any 

 position, from the vertical to the horizontal. The photographs show it 

 arranged for the latter. 



The machine is completed and ready for use, and Mr. North hopes 

 during the ensuing year to be able to make a number of experiments 

 Avith it upon the effect of varying amounts of work upon the elimination 

 of nitrogen. 



" These have not been engraved, as they represent the machine in a state not 

 quite perfected. 



