400 



Mr. D. T. Harris. 



During stimulation of the lingual nerve there is the same concentration 

 within the limits of experimental error, of lactic acid in the blood of the 

 lingual vein as there is in the femoral arterial blood (vide infra). Thus one 

 finds the lactic acid increased about five-fold in the venous blood of these 

 experiments, in which the blood flow was maintained at twice its normal rate 

 by interrupted faradisation of the motor nerve ; if the normal rate of venous 

 outflow had prevailed then the lactic acid concentration would have risen ten- 

 fold ; and in tetanus its concentration must be tremendously high. 



The production of lactic acid would lead one to expect a reduction in the 

 alkali-reserve according to the equation 



H.C 3 H 6 08 + NaHC0 3 = NaC 3 H 5 03 + H 2 + C0 2 



but estimations show a simultaneous increase in the alkali-reserve : — 









Ton 



gue. 







Alkali reserve of 



Besting. 



During stimulation of 



plasma. 



Lingual nerve. 



Hypoglossal nerve. 





Venous. 



Arterial. 



Venous. 



Arterial. 



Venous. 



Arterial. 



Dog 15 



55 



55 



54-5 



55 



59 



54 



, 16 



71 



70 



71 



71 



82 



76 



„ 17 



„ 18 



64 

 52 



64 

 50 -5 







83 

 69 

 64 



74 

 64 

 54 



„ 19 







49-5 



50 



57 



50 



„ 20 



61 



59 



60 



59 



73 



59 



„ 21 







47 



48 



59 



43 

















Mean v — a 



1 

























This absolute rise of nine in the alkali-reserve on a mean arterial alkali- 

 reserve of 52*5 is equivalent to an average increase of 16 per cent. It is 

 abundantly clear that both C0 2 and lactic acid are important metabolites of 

 muscular activity. Fletcher (1907) found that an evolution of C0 2 follows a 

 production of lactic acid in the frog's gastrocnemius. 



The carriage of such large increases of acid by the blood became a problem 

 of so much interest that the relative part played by plasma and corpuscles 

 was investigated. The blood was collected under paraffin, NaF being used 

 as an anti-coagulant, since it possesses the double advantage of not interfering 

 with the estimation, and also preventing glycolysis (Clogne et Eichaud), 

 glycolysis having been shown to be associated with the formation of lactic 



