x 
INORGANIC SALTS TO MONILIA SITOPHILA 269 
and fifty cubic centimeter Jena flasks. New bottles and flasks 
were obtained and a different set was used for each of the salts 
tested. Thus the same flask was never used for testing more 
than one salt. This prevents errors which might arise through 
small traces of one salt being taken up by the glass and carried 
into cultures of some other salt. All glassware used in the making 
of media or the growing of cultures was first treated for at least 
twelve hours with a chromic acid cleaning solution. It was then 
thoroughly rinsed with tap water and drained. After draining 
for a short time it was again rinsed, first in distilled water and 
then in triple distilled water. The water used in the making of 
culture media was triple distilled, once from acid potassium 
dichromate, once from alkaline potassium permanganate and then 
again redistilled. This water gave a resistance of approximately 
one hundred and twenty thousand ohms. All of the salts used . 
were Baker’s analyzed chemicals, except in the case of barium 
chloride, cobaltous chloride and cadmium chloride, which came 
from Kahlbaum. The glucose, saccharose, soluble starch and 
peptone were obtained from Kahlbaum; the lactose came from 
Merck. Five per cent. solutions of each of these substances 
gave the following resistances; glucose, fifty-six thousand ohms; 
saccharose, forty-nine thousand ohms; lactose, twenty-seven 
thousand ohms; soluble starch, three thousand, three hundred 
ohms; and peptone two thousand ohms. A comparison of these 
resistances gives a good idea of the relative purity of the organic 
substances used. 
The concentration of the salts in the various media are ex- 
pressed in terms of molar solutions; these concentrations were 
made by dissolving some multiple or some fraction of a gram 
molecular weight in one liter of solution. Twenty cubic centi- 
meters of medium were placed in each flask, and the flask and 
medium were sterilized for approximately ten minutes at 100° C. 
As soon as the medium had thoroughly cooled it was inoculated 
with fresh ripe spores of Monilia. The spores used in inoculating 
any given series of media were taken from the same culture. 
They were shaken from the culture flask on to a piece of white 
Paper and were thoroughly mixed by means of a sterile scalpel. 
Approximately equal quantities of spores were dusted over the 
