346 



THE ROTHAMSTED EXPERIMENTS. 



Zuntz and 

 Lehmann's 

 experi- 

 ments. 



The results show, over the first three experiments, some, 

 but not great, variation in the amount of nitrogen eliminated 

 with exercise; but the amounts are less in the fourth and 

 fifth experiments, and almost identical with walking and 

 trotting. Upon the whole, there is no evidence of direct con- 

 nection between the amount of exercise of force and that of 

 nitrogen eliminated in the urine. 



The next results give very definite evidence as to the con- 

 nection between the amount of carbonic acid exhaled, and 

 that of the force exercised. The experiments were made with 

 a horse, by Zuntz and Lehmann, in 1887 and 1888, 1 and the 

 average results were as follows : — 



Exhalation 

 of carbonic 

 acid at 

 work and 

 rest. 



F. Smith's 

 results. 



Rest . 

 Work 

 After work 



Carbonic acid exhaled per hour (average). 

 With Mask. With Tracheal-canula. 



3.327 cubic feet. 2.861 cubic feet. 

 19.643 m 17.291 n 



4.662 n 3.899 .. 



Thus, then, there were about six times as much carbonic 

 acid exhaled per hour during work as in rest ; and when the 

 work had ceased, there was very great reduction in the amount 

 of carbonic acid given off. 



The following results by Professor F. Smith, of Aldershot, 

 were published by him in the Journal of Physiology 2 in 

 1890 :— 



TABLE 81. 



As in the experiments of Zuntz and Lehmann, quoted 

 above, the great increase in the amount of carbonic acid 

 exhaled during work, and the great reduction in the amount 

 after the cessation of the work, are here again clearly 

 illustrated. 



Table 82 summarises numerous results, by Professor F. 

 Smith, with horses at different paces (loc. cit., p. 77). 



These strictly gradationary results, with one slight excep- 

 tion, illustrate more clearly still the greater exhalation of 

 carbonic acid the greater the exercise of force. 



1 Landw. Jahrbiicher, vol. xviii., 1889, p. 1. 



2 Vol. xi., No. 1. 



