September 4, 1903.] 



SCIENCE. 



307 



Table II. Solutions of NaOH. Bexjuk May 26, 10 a.m.. Closed May 28, 10 a.m. 



Table III. Solutions of HCl. Begun June 1, 10 a.m.. Closed June 3, 10 a.m. 



Remarks. 



Distilled. Growth in 



Remarks. 



n/356 



n/256 

 n/512 

 n/512 

 n 1024 

 n/1024 



n/2048 

 n/2048 



Probably only elongated. 

 Roots have pallid appearance. 

 Knots have pallid appearance. 

 Natural appearance. 

 Natural appearance. 

 Natural ajjpearance. 

 Natural appearance. 

 The root grew in a curve of 



180°. 

 The root grew in a curve of 

 i more than 180°. 



H,0 



146 1 Total growth. 



138 



Coagulated, dead. 



Coagulated, dead. 

 Natural, alive. 

 Natural, alive. 

 Natural, alive. 

 Natural, alive. 



Completed a circle. 



Completed the circle then grew 

 .straight up. 



Total growth. 



Table IV. Solutions of HjSOj. Begun June 4, 10 a.m., Closed June C, 10 a.m. 



By comparing the total growth in H^SO, 

 with the total growth in HCl we see that 

 the amount of growth in H.SO, was over twice 

 the total growth in HCl, but the difference 

 in the total growth in H^O after the seedlings 

 were taken from the acid solutions was but 

 small (20 mm.). This suggests that the ions 

 in the HCl solutions produce a greater toxic 

 effect upon the seedlings than tlioso of H,SO,. 



By comparison of the above tables we see 

 that at the dilutions of the compounds used, 

 the toxic effects of KOH and NaOH are prac- 

 tically the same, and the toxic effects of 11(^1 

 and H,SO are approximately the same. 



In regard to the degree of dissociation of 

 strong bases Arrhenius says:* " In the saponi- 



* .Arrhcnius, 'Text-Book nf Klcctrn-ClnMiiislrv.' 

 p. 184. 



