7) TOXIC EFFECT OF DELETERIOUS AGENTS 317 
hence both more nearly approximated the toxic value of ionic 
H. This toxic power of the un-ionized molecule these workers 
termed its “specific poisonous effect.” 
According to this reasoning, then, were HCl and HNO, both 
completely ionized we should expect to find them equally toxic. 
_ This matter has been fully tested by Kahlenberg and True (’96). 
They found that toward Lupinus which is killed by a —*_ con- 
3200 
centration of ionic H, they and all other completely ionized 
acids with non-toxic anions had exactly the same toxic value. 
The influence of HNO, on germination was much the same 
nH ' ° 
a that of HCl, ead causing distinct retardation of both germi- 
_ tation and early growth. Later, however, a marked difference 
the appearance of the cultures manifested itself. Cultures 
‘ontaining the HNO, in = to Pe concentration produced in _ 
_ ‘Marly every case a much heavier mycelium than in the corre- 
ponding cultures in HCI. Fruiting was retarded, but not so 
 ‘Seatly retarded as was usually the case where mycelial develop- 
“Ment Was so Strongly stimulated. 
oo The stimulation of mycelial development was possibly due to 
the non-toxic nitrogenous NO, ion. Cultures of Aspergillus and 
Eocephalum in = solutions of KNO,, however, did not estab- 
ih this View, as they did not greatly differ from those in similar 
ahaa of KCl and K,SO,, although the concentration 
__$ 0s would in this case be some forty times as great as in 
“Cultures. of HNO, showing the most stimulation. A more 
_) Pfoposition is that it was due to the same factor as the 
‘the : @ toxicity, viz., the un-ionized molecules. The fact that 
«tal appearance of the cultures resembled that of cultures 
«ted by the oxidizing poisons considered later would suggest 
7 Ff the nitric acid molecule as being the active influ- 
th The fact that fruiting was not greatly retarded, consider 
— mycelial development, is in harmony with this 
n 
