Dr. Baxter has executed a great number of very careful experiments,
with a view to testing the different disinfecting properties of the
so-called disinfectants commonly used. Evidence was adduced to show
that carbolic acid, sulphur, permanganate of potash and chlorine
are all endowed with true disinfectant properties, though in very
varying degrees. The effectual disinfectant operation of chlorine
and permanganate of potash appeared to depend far more on the nature
of the medium through which the particles of infective matter
are distributed than on the specific character of the particles
themselves.
A virulent liquid cannot be regarded as certainly and completely
disinfected by sulphur, unless it has been rendered permanently and
thoroughly acid. No virulent liquid can be considered disinfected by
carbolic acid, unless it contains at least two per cent., by weight,
of the pure acid.
When disinfectants are mixed with a liquid, it is very important to
make sure that they are thoroughly incorporated with it, and that no
solid matters capable of shielding contagion from immediate contact
with its destroyer be overlooked.
Aerial disinfection, as commonly practised in the sick room, is
either useless or positively objectionable, owing to the false sense
of security it is calculated to produce.
To make the air of a room smell strongly of carbolic acid, by
scattering carbolic powder about the floor, or of chlorine, by
placing a tray of chloride of lime in a corner, is, so far as the
specific destruction of contagion is concerned, an utterly futile
proceeding.
The practical result of these experiments goes to prove, first, that
dry heat, when it can be applied, is probably the most perfect of
all disinfectants; second, that the old plan of stopping up crevices
and fumigating with sulphur and charcoal is more efficacious than
any other proceeding with more modern disinfectants; third, that the
use of carbolic vapor for disinfecting purposes should be abandoned,
owing to the relative feebleness and uncertainty of its action.