58 



Scientific Proceedings (56). 



and the tube is placed in a boiling water bath for ten minutes. 

 The contents of the tube are then cooled and washed quantita- 

 tively into a 10 c.c. volumetric flask. After making up to the 

 mark, the red solution is filtered into the colorimeter chamber 

 and read at once against a standard freshly prepared by the same 

 procedure from 1 c.c. of a solution containing 1 mg. of dextrose 

 per c.c. The standard is usually set at 15 mm. 



If less than 2 c.c. of blood is collected, the quantities of N/100 

 acetic acid and of dialyzed iron must be correspondingly decreased. 

 With I c.c. of blood 20 c.c. of the clear filtrate are taken for dex- 

 trose determination; with 0.5 c.c. of blood the coagulum must be 

 thoroughly washed and the entire filtrate and washings used for 

 analysis. In the latter case the standard is made one half as 

 strong as usual and set at 30 mm. 1 



The method suggested yields results closely approximating 

 those obtained by the Allihn gravimetric method. 



35 (852) 



Electric currents in conductors with distributed capacity con- 

 sidered in relation to the propagation of the nerve impulse. 



By Albert C. Crehore and Horatio B. Williams. 



[From the Department of Medicine of Cornell University and the 

 Physiological Laboratory of Columbia University.} 



Nearly two centuries ago it was surmised that the nervous 

 impulse might be of the nature of an electric current, but in the 

 absence of definite proof the hypothesis was rejected, especially 

 as objections were raised to it which seemed insuperable. It is 

 difficult, if not altogether impossible, to reconcile all experimental 

 results with the consequences of the molecular theory. If, how- 

 ever, we regard the nerve as an electrical conductor with dis- 

 tributed capacity, we are able to account for many of the funda- 

 mental experimental phenomena and also to predict the results of 

 new experimental conditions. It has long been known that the 

 speed of electricity on wires is less than the speed in free space 



1 The reading of 10 c.c. of solution at 30 mm. in a Duboscq colorimeter is quite 

 possible if a piece of thick glass tubing 50 mm. long and 16 mm. inside diameter is 

 placed in the colorimeter chamber. 



