530 



STUDIES ON RESPIRATION. XV 



Fig. 3 shows antagonism between NaCl and Na taurocholate. In 

 this figure the abscissae represent the molecular proportions of each 

 component in the mixture: thus the ordinate at the extreme left rep- 

 resents the rate in a pure solution of NaCl; the ordinate at the extreme 

 right, the rate in a solution containing 95 parts of NaCl and 5 parts of 

 Na taurocholate. In a solution containing 1 part of Na taurocholate 



Rate of CO2 production 

 1007of '^ 



99.99119 Na CI 

 0.00881 Na taurocholate 



95 Na 01 



5 Na taurocholate 



Fig. 3. Curve showing antagonism between NaCl and Na taurocholate. 

 The ordinates represent the rate of respiration (expressed as per cent of the 

 normal) ; the abscissae represent molecular proportions of the solution used. Thus 

 the ordinate at the extreme left represents the rate in 0.8 m NaCl while the ordi- 

 nate at the extreme right (in the lower figure) represents the rate in 95 parts of 

 NaCl and 5 parts of Na taurocholate (molecular proportions) . Mixtures in which 

 the proportion of Na taurocholate was greater showed no respiration. 



Since the changes near the beginning of the curve could not be shown accu- 

 rately this portion is represented on an enlarged scale in the upper part of the fig- 

 ure. The optimum proportion for the production of CO2 is 99.9931 parts of NaCl 

 and 0.0069 parts of Na taurocholate. Normal rate as in Fig. 1. Average of 

 three experiments; probable error of the mean less than 2 per cent of the mean. 



to 14,375 parts of NaCl the rate of respiration was practically normal. 

 In all other proportions it was less than normal. For the sake of clear- 

 ness, the portion of the figure at the extreme left has been drawn on an 

 enlarged scale and is inserted above. These proportions are quite 

 different from those found by Osterhout (500 of NaCl to 1 of Na tauro- 

 cholate) to be most favorable, but the difference may be due to the 



