INORGANIC SALTS TO MONILIA SITOPHILA 271 
obtained through a number of preliminary experiments. It was 
impossible to predict what the limit concentration would be in any 
case. My method was to make a guess at this value and then test 
the accuracy of the guess through experiments. In some cases 
only one preliminary experiment was necessary in order to deter- 
mine the approximate value of the limit concentration of a given 
salt in one of the media. In other cases, however, several pre- 
liminary experiments had to be made before this value was ascer- 
tained. The data given in the tables was obtained in the final set 
of experiments and shows the great influence of the organic part 
of the medium on the toxicity of the different chlorides. The 
tables are arranged in the order of the toxicity of the salts tested. 
The influence of the medium on the toxicity of potassium chloride 
is shown in Table I. 
TABLE I 
THE TOXICITY OF POTASSIUM CHLORIDE IN SACCHAROSE, GLUCOSE, LACTOSE, STARCH, 
AND PEPTONE MEDIA 
Saccharose 5% Glucose 5% | Lactose 5% Starch 5% Peptone 5% 
+ Sad | ee G.M, Conc, AS °. M. Conc, — G.M, Conc, geal oo | yg 
KCl | 3 Days KCl 3 Days KCl 13 Days KCl 3 Days | KCl | 3 Days 
hi | = 2.3 - 1.6 ye is - yA cs 
2.2 | _ 2.2 _ BS ho I.4 oe ee i - 
2.1 er Le — | EA tee a3 - ‘2 - 
67s 2.0 — | 3 ; o— 1.2 - L222 = 
1.9 baie Pee ie ae Sigel vere 1.1 - it | ae 
1.8 | + 6) = 1 ae ean seme I.0 _ 1 
oe 1.7 see + 9 a ae 
1.6 + ga ee ae 9 8 + Se ete 2 
1.5 | + ee ree sate 824 7 — “yi ea x 
1.4 | + | I.4 | se, 7 : + 6 os ee | ie 
A glance at the table shows that the toxicity of potassium 
chloride is decidedly influenced by the medium in which it is 
offered. It is more than twice as toxic in starch as in saccharose 
or glucose. It is also more toxic in starch than in lactose and 
peptone. Its toxicity in lactose is the same as in peptone, but is 
about thirty-five per cent. less than in saccharose. It is most 
toxic in starch and least toxic in saccharose. The average of the 
limit concentrations in the five media is 1.1 molar and shows that 
potassium chloride is less toxic than any of the other chlorides 
. that I have tested; this may be associated with the high nutrient 
