JOSEPH KRAFKA, JR. 455 



In bar eye, N is reduced to Bx at Ti°, to By at T2°. 



Bx 



Facets are formed then at the rate of — per t at Ti°. 



n 



Facet number is reduced at the rate of — — — per t at Ti°. 



n n 



Facets are produced at the rate of By per t at To°. 



Facet number is reduced at the rate of N — By per t at T2°. Then 

 the rates of production and reduction have the following temperature 

 coefi&cients. 



In all the bar stocks, Bx is greater than By, where Ti is the lower 

 temperature. Hence the temperature coefficient for the reduction 

 reaction in bar is greater than that of the production reaction. We 

 can thus explain the difference in temperature relations between the 

 full-eyed stocks and the bar-eyed stocks. 



How can we explain the differences for the various bar-eyed stocks? 

 From the above formulas it is obvious that the greater the difference 

 between Bx and By the greater will be the difference between the 

 Qio for full and for bar. Bar is a changed condition which differs 

 from the full in number of facets and also in the temperature coef- 

 ficients of some of the reactions concerned in facet production. Is 

 Ultra-bar a change in the same direction? 



Ultra-bar effects a further decrease in the number of facets. But, 

 as seen by the values of Ex and By, its temperature coefficient is 

 really nearer that of the full than is that of the other bar stock. 

 Ultra-bar is then not an increased condition of both these factors. 

 The reversed change in the temperature coefficient may be a question 

 of the concentration of the inhibitor. 



