342 



THE ROTHAMSTED EXPERIMENTS. 



Interview 

 with Voit. 



Further 

 trials by 

 Voit. 



Former 

 views over- 

 turned. 



Experi- 

 ments by 

 Pettenkofer 

 and Voit. 



body, in connection with the disposition of the increased 

 amount of nitrogenous substance consumed ; so that, after all, 

 the amount of urea eliminated was a measure of the exercise 

 of force, though not in the voluntary exercise of muscular 

 power. 



One of us being in Germany in the summer of 1860, and 

 visiting Munich, had some conversation with Professor Voit 

 on the subject of their results and conclusions. Referring to 

 our own results obtained in 1854 with pigs, it was pointed 

 out that they were entirely consistent with those which he 

 and Professor Bischoff had obtained with a dog, but that we 

 had drawn very different conclusions from them. He con- 

 veyed the impression, however, that he considered we were 

 entirely in error. 



Later in the same year, however, Voit published J the results 

 of further experiments with a dog. In these, he submitted 

 the animal to alternate rest and labour, sometimes fasting, 

 sometimes with a moderate, and sometimes with a liberal 

 supply of nitrogenous substance in food. The labour con- 

 sisted of working in a kind of treadwheel. He found that 

 the amount of urea eliminated was not in proportion to the 

 exercise of force, but was very nearly proportional to the 

 amount of nitrogenous substance consumed. He considered 

 that by such a result the views which he and others had 

 maintained as to the connection between the exercise of force, 

 the degradation of nitrogenous substance within the body, and 

 the elimination of urea, were completely overturned. 



In 1862 Pettenkofer and Voit published a paper 2 giving 

 the results of experiments with a dog made in 1861 and 

 1862, in which the food consumed, the amount of urea voided, 

 and the quantity of carbonic acid given off by the lungs and 

 skin, were determined — the latter in Pettenkofer's respiration 

 apparatus. These experiments were more or less preliminary, 

 and during their conduct the animal was not submitted to 

 any labour. 



Subsequently, Pettenkofer and Voit made experiments in 

 which they determined both the nitrogen in the urine, and 

 the carbonic acid evolved, not only in rest but in work ; 

 sometimes fasting, and sometimes with food. Their results 

 were published in 1866 in the Zeitschrift fiir Biologic Table 

 78 gives average results for twenty-four hours, in experiments 

 made with a man, with the aid of Pettenkofer's respiration 

 apparatus. 



Thus, not only was there no increased transformation of 



1 Untersuchungen iiber den Einfluss des Kochsahes, Kaffees und der MusTcel- 

 bewegungen auf den Stoffwechsel, 1860. 



2 Ann. Cliem. Pharm., II. Supplement-band, I. Heft, p. 52. 



