output is affected (Pettenkofer and Voit(c)). In the same year Senator 

 searched in vain for evidence of incomplete oxidation in dogs, cats, and k 

 rabbits with tightly bound thorax (Senator(a)). In 1870 and 1871, Voit 

 discussed the whole subject at great length, and answered especially, the 

 objections of Liebig who was teaching the old view (Pettenkofer and Voit 

 (e), Voit(/) ). All these points have since been taken up by more accurate 

 methods, and it has been demonstrated that the gaseous exchange is not 

 affected by any of the factors mentioned in the preceding paragraph 

 (Finkler, Gurber(a), Jackson, Magnus-Levy (a), Lukjanon, Moller). 



Hoppe-Seyler accepted the new theory almost from the beginning, but 

 did not feel that the experimental proof was complete until 1878 (Takacs). 



Pfliiger, who at this time was working on the gasometry of the blood, 

 vigorously opposed the new view (Pfliiger(a) (6), Pfliiger and Zuntz, Zuntz 

 (a) ) . In 1868 he stated : "No one will deny at the present day that oxygen 

 is continuously used up in the blood vessels," and described experiments of 

 his own and similar ones by Schmidt in Liebig's laboratory, intended to 

 demonstrate the presence in the blood, during suffocation, of products of 

 incomplete oxidation (Pfliiger (d}}. He declared also that dyspnea is due 

 to products of incomplete oxidation ( Pfliiger (c)). 



But Pfliiger soon changed his opinion ; he disproved his earlier find- 

 ings of products of incomplete combustion in the blood, and, in 1872, re- 

 jected the old hypothesis, going even so far as to assert that he had recog- 

 nized and taught the correct theory, even before Voit (Pfliiger(e) ). In 

 extra large type, on page 46 of this paper, occurs the following very 

 important sentence which expresses the views of physiologists to-day: 

 "Here lies (in the cell itself alone) the essential secret of the regulation 

 of the oxygen used by the body ; it is not determined by the blood pressure, 

 the velocity of the blood stream, or the activity of the heart, or the activity 

 of the respiration." 



In 1875, both Voit(^) and Pfliiger(/) complain that the view is not 

 everywhere known and accepted; according to Voit, even Liebig still 

 opposed it. But that the results are not everywhere ignored is shown by 

 Voit's further complaint against those who say that they recognized and 

 demonstrated the truth before he (Voit) did; he disputes especially 

 Pfliiger's priority claims. 



During the years 1875 to 1878, a great many papers on respiration 

 and metabolism appeared from Pfliiger's laboratory (Finkler, Pfliiger(gr) 

 (fc)(t)(/)(fc)(Z)(m)(n)(o). Many of them are very long, and offer 

 as evidence not only Pfliiger's experiments, but an enormous amount 

 of other evidence from all departments of biology. Pfliiger's own 

 experiments deal largely with measurements of the amount of metab- 

 olism under conditions of varying oxygen supply. The papers arc 

 polemic in character, and their influence on other physiologists is re- 

 flected in the gradual change in the nature of the discussion. The earlier 



