MEASURING ELECTRICAL CONDUCTIVITY 39 



all of them equally. This answers very well as long as 

 we are comparing experiments which last about the 

 same length of time, but it may happen that one of the 

 series lasts but a short time and after its completion the 

 others proceed at a different temperature. In this case 

 the whole series should be rejected unless the difference in 

 temperature is small. 



The temperature coefficient of the electrical conduc- 

 tivity of living Laminaria 22 is about 1.331 ; this is higher 

 than that of dead tissue (1.26) which is very close 

 to that of sea water. This coefficient may be employed to 

 correct readings which are not made at the standard 

 temperature, provided the deviation in temperature does 

 not exceed two or three degrees. 



22 



Cf. Osterhout (1914, /). 



