38 



Hydration and Growth. 



and hydrochloric acid taken from a solution by various materials comes 

 within the range of this chapter. In these tests 3 to 6 grams of the 

 colloid or of the plant material were placed in a dish containing about 

 100 c. c. of the acid solution at 21° C. The results are given in table 18. 



Table 18. — Water absorbed from hydrochloric acid per gram dry s^ibstance. 



Material. 



Agar A 



Agar B 



Agar C (only one determination in each 



cone, for agar C) 



Agar A (48 hours) 



Agar A (4 days) 



Agar A (7 days) 



Agar A (10 days) 



Agar A (14 days) 



Agar-gelatin 



Gelatine (Cox's) 



Lupiuus albus cotyledens 



Vicia faba cotyledons 



Phaseolus lunatus cotyledons 



Starch (commercial "corn starch") . . . . 

 Coconut (commercial shredded, after 



removal of oil and sugar) 



Concentration. 



N/20. 



2.312 

 4.242 



4.275 



4.520 

 14.362 

 1.368 

 1.096 

 1.169 

 .822 



5.884 



N/10. 



2.164 



3.917 

 2.944 

 3.693 

 2.688 

 2.678 

 2.731 

 4.065 

 9.830 

 1.504 

 1.163 

 1.181 

 .804 



5.891 



N/5. 



3.497 

 3.670 



3.821 

 5.892 

 1.614 

 1.112 

 1.257 

 .786 



5.646 



N/2. 



3.571 

 3.461 



3.913 

 5.019 

 1.602 

 1.079 

 1.210 

 .812 



5.678 



The amount of acid absorbed was greatest in all cases from the high- 

 est concentrations used. The amount of hydration which accom- 

 panied the incorporation of the acids in the colloids is given in 

 table 19. 



Table 19. — Absorption of hydrochloric acid and water from solution, per gram dry 



substance. 



Material. 



Agar A 



Agar B 



Agar C (only one determination 

 in each concentration for 

 agar C) 



Agar A (48 hours), 4 determi- 

 nations 



Agar A (4 days), 2 determina- 

 tions 



Agar A (7 days), 3 determina- 

 tions 



Agar A (10 days) , 3 determina/- 

 tions 



Agar A (14 days), 1 determina^ 

 tion 



Agar-gelatine 



Gelatine (Coxe's) 



Lupinus albus cotyledons 



Vicea Faba cotyledons 



Phaseolus lunatus cotyledans . . 



Starch (commercial starch) .... 



Coconut (commercial shredded 

 after removal of sugar and oil) . 



Hydrochloric acid, grams. 



N/20. N/10. N/5. N/2. 



0.01115 

 .01177 



.01331 



.01941 

 .04130 

 .00843 

 .01269 

 .01256 

 .00269 



.02344 



0.01591 



.02151 



.01735 



.01913 



.01476 



.01386 



.01373 

 .02508 

 .06577 

 .01700 

 .01918 

 .01996 

 .00442 



.03585 



0.03168 



.03457 



.03433 

 .06991 

 .02490 

 .02636 

 .02672 

 .00779 



.04789 



0.06990 



.06892 



.07705 

 .11075 

 .04173 

 .03191 

 .03482 

 .01434 



Water, grams. 



N/20. N/10. N/5. N/2, 



2.312 

 4.242 



4.276 



4.520 

 14.362 

 1.368 

 1.096 

 1.169 

 0.822 



6.884 



2.164 



3.917 

 2.944 

 3.693 

 2.688 

 2.678 



731 

 066 

 830 

 604 

 163 

 181 

 804 



6.891 



3.497 



3.570 



.821 

 ,892 

 614 

 ,112 

 ,267 

 ,786 



5.645 



3.571 



3.461 



3.913 

 5.019 

 1.602 

 1.079 

 1.210 

 0.812 



5.678 



