30 REPORT OF THE BACTERIOLOGIST OF THE 
action of mold. Table stain can be controlled by carefully wash- 
ing the shelves to remove the mold, followed by burning sulphur, 
and attention to the ventilation. 
FALSE THEORIES AS TO CAUSE OF RUSTY SPOT. 
Many explanations have been advanced by different persons 
to account for the appearance of these rust-colored spots in 
cheese. From their color it was at first supposed that the spots 
were due to iron rust from handling the milk in old cans or rusty 
vats. A chemical examination showed that these rusty looking 
portions contained only a trace of iron, no more than is found 
in a normal cheese. Some buyers held that the trouble was due 
to adding cheese-color irregularly, but the trouble was very bad 
in factories where no color had been used. 
Poor salt has been blamed, but the trouble is found in factories 
using the very best grades of salt and has come and gone while 
the same barrel of salt was in use. 
The fact that the trouble does not appear until the cheese is 
some days old and that from this time it continues to increase 
for some days plainly indicates that it is due to the action of some 
form of life in the cheese. 
HISTORY OF RUSTY SPOT. 
OUTBREAKS IN THE STATE. 
The earliest reported appearance of rusty spot in this State 
was in St. Lawrence County in 1883. For many of the facts con- 
nected with this outbreak we are indebted to Mr. W. W. Hall, 
who was a resident of this county and prominent in cheese mat- 
ters at that time. In July of that year the rusty spots were 
noticed in the cheese at the Elmdale cheese factory near 
Gouverneur. 
The factorymen were utterly at a loss to account for them as 
they were making white cheese and had used no coloring matter. 
The trouble did not develop to any considerable extent and about 
September 1 it disappeared for the remainder of that year. The 
following season it was much worse and continued longer. 
The trouble spread until nearly all of the factories in that sec- 
tion were affected to such an extent that at times they resorted 
