1896] TOXIC ACTION OF DISSOLVED SALTS 109g 
mixed the resulting solution has an acid reaction caused by the 
presence of hydrogen ions that have resulted from the electro- 
lytic dissociation of a complex boro-mannitic acid that has been 
formed in the solution. We should, therefore, expect such a 
solution of boric acid mannite, containing more hydrogen ions 
than a solution which contains the same amount of boric acid 
but without the mannite, to have a greater toxic effect than the 
latter. Table 40 shows results that confirm this. Cane sugar and 
boric acid do not form a complex acid with each other, conse- 
quently no increase of concentration of hydrogen ions is caused 
by mixing them, and of course we should expect the mixture 
to have the same toxic action as an equivalent solution of boric 
acid without addition of cane sugar. A comparison of tables 
38 and 41 shows that this is in accord with experimental facts. 
In his extensive work on the affinity of constants of 
organic acids, Ostwald?3 determined the electrical conductivity 
of a large number of acids, thus giving us a knowledge of the 
degree to which these acids are dissociated in their solutions. 
The most dilute solutions with which he worked contained I gm 
equivalent in 1024 liters. Only a relatively small number of the 
acids he investigated are highly dissociated at this concentration. 
In investigating the toxic effect of organic acids upon the 
lupines, it was found that the concentrations in which the plants 
would just survive are less than 1 gm. equivalent in 1024 liters, 
So that it is impossible from Ostwald’s determinations to tell 
- what degree the acids are dissociated at these higher dilu- 
tions. In only a few of the cases investigated can the acid be 
considered as practically completely dissociated, as was done in 
nee of the strong mineral acids, so that the effect of the undis- 
sociated acid present cannot be left out of account. This anion, 
too, in many cases no doubt exerts a distinct poisonous action 
of its own, 
‘Typical acids from the fatty series and from the aromatic 
series Were investigated. The results are given in the tables 
that follow. 
* Zeitschr. f. physik. Chem. 33170, 241, 369. 
