two
gases ought to be used in every case; otherwise the room may continue to
harbor germs of the disease for months or years with the possibility of
infecting a future tenant at a time when his vitality was such as to
make him an easy prey. Nor must the contents of the room be overlooked.

The writer was recently told of a large family where one child had
scarlet fever, recovering in September. The sick room was thoroughly
disinfected, but the careful housewife, fearing damage to her blankets,
had taken them to the attic before disinfection began. In the cold
weather of February these blankets were brought down, and in six days
the two children sleeping under them had contracted the disease.

_Sulfur as a disinfectant._

When sulfur is burned, a gas is formed known as sulfurous acid, and
until the last few years, it was the most common of all disinfecting
agencies. The writer well remembers that when about to visit a city in
South America infested with yellow fever, he was seriously advised to
fill the inside of his shoes with sulfur as a precaution against the
disease. He might as well have worn a red ribbon on his hat so far as
any protection went, but it illustrates the confidence formerly shown in
sulfur as a disinfectant.

It is now known that in the dry, powdered state, sulfur is of no value
unless, perhaps, the germs be smothered with the sulfur flour. When
burned, however, the gas given off has a certain disinfecting property,
although this is limited. It has almost no power of penetrating into
curtains, blankets, and upholstered furniture, although the penetration
is decidedly increased if these objects are moistened either by steam or
by water vapor. The proper amount of sulfur to be burned for any room is
at the rate of 3 pounds per 1000 cubic feet of air space in the room.
Thus, if a room be 12 feet by 15 feet and 8 feet high, containing 1440
cubic feet, it would be necessary to burn 144/100 of 3 pounds, or 4-1/3
pounds.

Before undertaking to disinfect a room with sulfur, it should be made
thoroughly air-tight, and this must be done carefully, not merely by
closing the larger and obvious openings, like doors and windows, but by
pasting strips of paper over every crack which might allow air to
escape. Thus the four edges of the window sash must be pasted up, and a
strip must close the crack between the two sashes. All the doors but the
one reserved for exit should be pasted up from the inside, and final