1896] TOXIC ACTION OF DISSOLVED SALTS 131 
The order of the poisonous action of these acids is, then, ortho, 
meta and para. This is also the order of their electrolytic dis- 
sociation, the degrees of dissociation of the three acids at the dilu- 
tion 1024 being 62.80 per cent., 25.70 per cent. and 15.68 per cent. 
respectively, according to Ostwald. Whether the toxic action 
of these acids at the concentration at which they are fatal to the 
lupines is due in part to the anions here also calls for an investi- 
gation of the sodium salts. 
As typical examples of other oxy-benzoic acids protocatechuic 
and gallic acids were chosen (see tables 70 and 71). The con- 
centration of the former in which the beans survive is 39'y5 gm. 
mol. per liter. The degree of dissociation of this acid at 1024 
is 16.68 per cent., somewhat higher, then, than para-oxy-benzoic 
acid, Considering the action of the hydrogen ions alone, we 
should expect protocatechuic acid to be somewhat more poison- 
ous than para-oxy-benzoic acid. It seems probable, however, 
that the action of the undissociated molecules and the anions can 
not be considered mJ at the concentration 3200. 
In the case of gallic acid, which is dissociated 18.72 per cent. 
at 1024, the seedlings survive only at the concentration 6400 as 
table 71 shows. Here clearly the anions and the undissociated 
molecules must have a toxic action of their own even at this 
high dilution, for the acid can clearly not be considered as com- 
pletely dissociated. 
70. PROTOCATECHUIC ACID. 
(Begun January 24, 8 p.M.; closed January 25, 3 P.M.) 
Concentrati os 
gm. mol. es fens Length Remarks 
réo0 0° flabby, dead 
a he, 17.8 “ “ “ 
ss00 24:5 alive 
ion 13.5 dead 
éFo0 27.0 “ alive 
gh a ae 29.0 ee oe 
tates 29.0 ‘“ “ 
eae ee 28.0 “ec “ 
Nee Noni SNR ene 
