3 84 . BO TA MCA L GA ZE TTE [may 



should be expected to give similar results, while the similarity of 

 results given by the copper ferrocyanide membrane and peanut 

 should not be expected. We may note, however, a parallel between 

 the method of observation employed and the coefficient obtained. 

 The first 3 observers studied the permeability of the membrane 

 indirectly, other structures such as cell contents and seed contents 

 being present. In the last two cases the membrane was measured 

 directly, without other structures being factors in the rates observed. 



It is questionable to what extent results obtained by the indirect 

 method may be referred to the membrane alone. There is the 

 possibility that the temperature effect may have been, not upon 

 the membrane merely, or upon the water exclusively, but also upon 

 the cell contents or seed contents. The latter effect may have 

 contributed to the total results from which the coefficients were 

 calculated. The chemical reaction indicated by the coefficient 

 2-3 may have taken place in that phase of the system that was 

 internal to the membrane studied. 



In these experiments the temperature may have exerted an 

 effect on the water, but if so the temperature coefficient does not 

 indicate that this was related to a chemical reaction. There is no 

 evidence of a temperature action in splitting the larger water 

 aggregates into simpler hydrone molecules as found by Brown and 

 Worley with the semipermeable membrane of the barley grain. 



Tendency of temperature coefficients to fall in value with increased 

 temperatures. — An inspection of the temperature coefficients ob- 

 tained in these experiments shows that the coefficients are higher 

 at the lower temperatures and lower at the higher temperatures. 



great many 



KANITZ (18) noted a number 

 this tendency. Snyder (29) 



some 



Q I0 , and Cohen- 



dine to the van't Hoff 



values of Q I0 are not constants and that the velocity is not an 

 exponential function of the temperature. Table VII indicates the 

 general tendency of Q I0 for different processes. Falling values 



Q 



10 



measurements made 



matter, (b) with non-living matter, (c) with a physical 



