316 BOTANICAL GAZETTE [NOVEMBER 
spores. Then, too, we are, perhaps, not justified in assuming 
that ionic K is entirely non-toxic; for although potassium is a 
necessary food element for all plants, may it not be that great 
concentrations of even so good a thing as ionic K may be bad 
for fungi? Later, this will be shown to be the case with iron, 
an element which, while absolutely necessary in small quantities 
for all plants (Molisch, ’94), is quite toxic in excess for both 
fungi and higher plants. 
Experiments with Aspergillus and CEdocephalum in KG 
solutions, however, enable us to say quite positively that for 
these forms the anion Cl has at most /ess than one thirty-second 
the toxic value of ionic H, and may therefore be disregarded in 
a discussion of the toxic properties of HCl. 
Nitric acid, HNO,; 48, r4z, 384. Ionized in almost the 
_ same proportion as HCl (Kohlrausch, ’85), HNO, proved much 
more toxic. Inasmuch as the concentration of H ions is pla 
' . xT . * “| n- 
tically the same as in HCl, and the NO, ion 1s practically vt 
toxic, having a toxic value of less than one thirty-second tha 
oo oe ‘ ie of 
ionic H, we must look for an explanation in the toxic valu 
the un-ionized molecule, HNO,. This was found to be approx 
ae 
mately 7.7 times that of ionic H?. In other word gree 
of HNO, loses nearly seven eighths of its toxic properties 
: iy 1? ) found that 
molds on becoming ionized. Krénig and Paul (’97 
‘ hours 
anthrax spores immersed in a solution of HNO, for two 
were entirely destroyed. A similar immersion A ee 
preparation of spores in the same concentration of H Ce 
the survival of 385 colonies. Preparations of spores - 
in te solutions of these acids, however, showed far less 2 
nae 1 distinctly mo 
in toxic properties, although the HNO, was still di + the Jat 
toxic. This was evidently due to the fact ne 7 | ioniteds 
concentration the acids were both much more highly eae 
?See table I, p. 325. 
