Phenolic Solutions by Seeds of Hordeum vulgare. 121 



solutions of phenol, catechol, resoreinol, quinol, and pyrogallol at 19° C. 

 Thus the nature only of the steeping solution was different, the temperature 

 and molecular concentration being the same in each case. 



(b) The second series of solutions was exactly similar to the above, except 

 that the steeping temperature was increased to 32 - 2° C. This series was 

 chosen in order to determine what difference would be made to the relative 

 rates of absorption by increasing the temperature, whilst keeping all the 

 other factors the same. 



(c) In the third series the various samples were steeped in solutions of 

 ordinary phenol of various strengths at 22 - 6° C, in order to determine 

 the effect of altering the concentration of a given solution at a constant 

 temperature. 



Experimental Determination of the Increase in Weight when the Seeds are 

 Immersed in the Various Solutions. 



(a) Seeds in Seminormal Phenolic Solutions at 19° C. — In this series the 

 solutions were made of equivalent strength (half molar by volume in each 

 case). Since they contained equal numbers of solute molecules their 

 osmotic pressures were consequently equal.* Xotwithstanding this fact, 

 however, the rate at which the solution is absorbed varies greatly. This is 

 shown in Table I and its corresponding curve, expressing the weight of the 

 original 5 grm. of seeds after stated intervals. 



Table I. — Temperature 19° C. 



Time from 







Weight of seeds immersed 



in 





beginning 

 of experi- 



























ment. 



Water. 



N/2 phenol. 



N/2 catechol. 



N 2 resorcinol. 



N/2 quinol. 



N 2 pyrogallol. 





grm. 



grm. 



grm. 



grm. 



grm. 



grm. 



hours 



5 -00 



5-00 



5 -00 



5 00 



5 -00 



5-00 



1 „ 



5-11 



5 -13 



5 12 



5 -10 



5 -13 



5-16 



24 „ 



6-08 



6-73 



6 31 



6 11 



6 -15 



6-08 



48 „ 



6-56 



7-22 



6 -91 



6 66 



6-69 



6-58 



72 „ 



6-94 



7-38 



7 "24 



7 07 



7-06 



6-96 



96 » 



7 15 



7-44 



7-34 



7 "25 



7-29 



7-21 



7 davs 

 - 



7 31 



7 -50 



7 -37 



7-39 



7 -40 



7 -3S 



* Assuming, of course, that dilute solutions of equal molecular concentration have 

 equal osmotic pressures. This is only so absolutely -when the solutions have also equal 

 heats of dilution and evaporation and equal surface tensions, and when the degree of 

 association of the solvent is the same in each case (Findlay, ' Osmotic Pressure,' 

 Chap. V). 



