12 



EXPERIMENTS WITH PLANTS 



discover if any cracks have been formed which might 

 admit water and so vitiate the results. 



It is interesting to calculate the percentage of water 

 absorbed and make a comparison after various periods 

 of immersion. 



The followinof will serve to illustrate the method: — 



Twenty-five Scarlet Runner 

 Beans sealed 



Twenty- five Scarlet Runner 

 Beans unsealed 



Weight be- 

 fore treat- 

 ment witli 

 i-ubber. 



31.0 grams 

 29.5 grams 



Weiglit after 



treatment 

 with rubber. 



Submerged in water 

 15 niinuies. 



Wt. 



32.0 grams 32.34 

 30.8 grams 31. G2 



Gain. 



0.34 

 0.82 



Per 

 cent 

 gain. 



1.1 



2.8 



After soaking fifteen minutes, the weight of the 

 sealed lot was 32.34 grams; subtract from this the 

 weight before soaking (32), which gives the gain 

 (0.34 grams) ; divide this by the original weight be- 

 fore treating with rubber (31 grams) to get the gain 

 in per cent. In this case an area on the unsealed 

 seeds was covered with rubber so as to equal the 

 amount covered on the sealed seeds. 



