PREVIOUS INVESTIGATIONS. 



17 



some important factors which are considered at the present time as 

 practically indispensable for successful respiration experiments. Thus, 

 he says that there was always a short period of rest before the observa- 

 tions began. He states: 



"We sat down at least a quarter of an hour before taking the first observa- 

 tion, or that which showed the state of the system before the substance under 

 inquiry was taken, and which was the basal state with which the subsequent 

 effects of the substance were compared, and upon the accuracy of which the 

 truthfulness of the results mainly depended." 1 



That he recognized the importance of quietness and uniform muscu- 

 lar activity is indicated by the statement: "the same conditions as to 

 posture and quietude being maintained unbroken throughout the whole 

 inquiry." Finally, we may cite one of the conclusions from his first 

 paper : 



"There is a normal or basal line below which the system does not pass in 

 health and wakefulness, and which is tolerably uniform. It is the same in the 

 complete abstinence from food as at the end of the interval between meals. 

 There is, also, when at rest, a higher point, which the system does not exceed, 

 due to food, and it is the highest after breakfast and tea." 2 



Ranke, 1861. The large respiration chamber constructed by Pet- 

 tenkofer and Voit in Munich was apparently used for the first time 

 with man in June 1861, for a series of experiments carried out by Ranke 

 upon himself and published by him. 3 In these experiments the subject 

 either fasted or was given an ordinary diet of undetermined nature, a 

 mixed diet of known composition, or an excessive meat diet ; the obser- 

 vations were all made in periods of 24 hours. The values are recorded 

 in table 2. 



TABLE 2. Carbon-dioxide production in fasting and food experiments (Ranke). 



Ranke's experiments are referred to in a subsequent publication by 

 Pettenkofer and Voit, 4 the statement being made that Ranke found in 



, Phil. Trans., 1859, 149, p. 717. 

 ., p. 712. 



'Ranke, Arch. f. Anat, Physiol., 1862, p. 311. 

 4 Pettenkofer and Voit, Ann. der Chem. u. Pharm., 1862-63, Suppbd., 2, p. 53. 



