Phenolic Solutions by Seeds of Hordeum vulgare. 125 



complete or partial disruption of the semipermeable membrane by the 

 solutions. That this is not so was shown in the following way : — ■ 



After each sample of seeds had attained fulness in the various seminormal 

 phenolic solutions at 19° C, they were slowly and carefully dried in air at 

 about 30° C. The samples were next immersed in pure water in each case, 

 and the rate of absorption of the pure water determined in the same way as 

 when the seeds were in the phenolic solutions. It is evident that, if any 

 sample had been damaged, it would have absorbed water more quickly than 

 the sample originally in pure water. It was found, however, that the rate of 

 absorption was almost exactly the same in every case as the rate for the 

 sample originally in pure water. A comparison of the corresponding weights, 

 after stated intervals of the two samples originally in water and seminormal 

 phenol, is given in Table IV. 



Table IV.— Temperature 19° C. 



Time 

 from beginning. 



Weight in pure water of seeds 

 originally immersed in 



Water. N/2 phenol. 



Difference. 



days. 



grm. 



grm. 



grm. 







4-71 



4 74 



-03 



1 



6-10 



6-25 



0-15 



2 



6-61 



6 71 



o-io 



3 



6-92 



6 95 



03 



4 



6-97 



7-02 



0-05 



7 



6-97 



7-10 



0-13 



It is apparent that the weight differences between the seeds originally in 

 N/2 phenol and water respectively are comparatively small, and within the 

 experimental error involved in prolonged manipulation — losses in weight 

 being caused by numerous dryings with a cloth. 



Discussion of the Absorption Curves. 

 (1) Equation to the Absorption Curves — 



It has been pointed out already that the rate at which the seeds absorb any 

 solution is dependent on the amount of solution which has previously entered 

 them (their degree of fulness), as well as on the nature of the solution. In 

 order to find the mathematical relationship existing between the absorption 

 rate and the degree of fulness, tangents were drawn to each of the curves in 

 Diagrams 1, 2, and 3 at points where the seeds had attained definite weights 



VOL. LXXXIX. — B. L 



