1896] TOXIC ACTION OF DISSOLVED SALTS 117 
what one would expect considering the degree of the dissocia- 
tion of this acid and the fact that at this concentration the hydro- 
gen ions alone are active. 
61. ASPARTIC ACID. 
(Begun January 24, 9 P.M.; closed January 25, 4 P.M.) 
Concentration 
gm. mol. per liter Length Remarks 
sooo 13.40" dead 
16 5 “ “oe 
epou os .b°2" alive 
“ 
ieee S10 
T2s00 20.0 “ 4 
ee 26.05 "% : 
Aspartic acid (table 61) has a strong toxic action, the seed- 
lings only surviving when the solution contains eaov gram-mole- 
cule per liter. The electrical conductivity of this acid is not 
given in Ostwald’s tables. It is not probable that the acid is 
completely dissociated at this concentration, however. Whether 
the anion is active toxically can be determined by investigating 
the action of the sodium salt of the acid. 
62. TARTARIC ACID. | 
(Begun January 15, 5 P.M.; closed January 16, 3 P.M.) 
1 
Concentration 
gm. equiv. per liter Length Remarks 
svo0 19,0" dead 
ed 20.0 * 
sfo0 20.0." alive 
tee ar 6, * ~ 
Tartaric acid (table 62) gives the limit ,) 9 gram equivalent 
Per liter. This acid is a relatively strong acid and is practically 
completely dissociated at this high dilution. We get only the 
effect of the hydrogen ions here, for a solution of sodium tar- 
trate of like strength would not kill the seedlings. : 
Citric acid (table 63) was investigated in this connection. 
The critical limit, sy!55 gram equivalent per liter, found for this 
