98 BOTANICAL GAZETTE 
case in solutions that are perfectly blue in color and contain qj 
gram atom copper per liter. The enormous contrast that this 
result presents with that obtained in the experiments in which 
the copper exists in the solution as ion (tables 14 and 15) 
apparent and shows that the copper ion is far more poisonots 
than the complex ion which contains copper. 
18. FERRIC CHLORIDE (FeCl, ). 
(Begun December 5, 9 P.M.) 
ae ae gig Boca ns. Remarks oe 
ae 
cr 0.0906 ones” 15.0" dead, mahogany red 
15.7 fe ae ae “ 
Fe, 0.00500 
cr Ate Suga 19.7 “ turgor gone, dead 
20.5 . “ ‘“ “ 
Fe, 0.00250 ) 
Ch nread totes 2L5°° 21.07" dead 
215 = are “6 
: (Concentration allowing growth not reached. Probably found at next 
with half the Fe and Cl content of the last in the table.) 
19. DIALYZED IRON (FeCl, ), 
(Begun November 21, 5 P.M.) 
Con i : Length 
reciguenes Nov, ag A.M, ape ye he 
ag i ae eee 
Fe, 0.009555 ; 
Cl, 0.0093 eae 18.5m dead, laterals oe 
“ “ “i “ : 
Fe, 0,004774% the 
Cl, 0.00047 ; ees 23.5" §1.5™™ living, surface reddish 
24.0 “ 62.0 “ . ss 4 
26.0 “ 5 . . 
joe ee] 
From table 18, giving the results obtained with ferric 
ride; it. 1s evident that ferric ions have a quite strong toxic: 
It is known that ferric chloride splits up hydrolytically in 
solutions, which makes this case somewhat complica 
main object, however, was to compare the action ‘ 
