The citizen. (Frederick City, Md.) 1895-1923, 1902-04-04
HEAT AND DISEASE.
The SUMS RAYS ARE FATAL TO MANY
SPECIES OF GERMS.

Sunlight is fatal to some of the lower
forms of living things, including GER
tain disease germs which are the cause
Of some of the most fatal infectious
diseases that afflict the human race.
In fact, the greatest disinfectant in ma
ture is light, or, to be more exact, the
iadiations of the sun, including heat
rays, light rays and the invisible rays
at the violet end of the solar spectrum.
An infectious disease is one which
may be contracted by the introduction
into the living body of living disease
germs, which may be contained in diff
fcrent kinds of infectious material.
Thus the disease germ (bacllus) which
produces diphthoria is contained in the
"exudate" or false membrane" de-
posted in the throat or nasal passages
of those suffering from this disease,
and the material coughed up by a pa
tient with diphtheria is infectious ma
terial In cholera and in typhoid fever
the discharges from the bowels con-
tain the germ and are consequently in
fectious material.
Now. the object of dsinfection is to
prevent the extension of infectious dis
eases by destroying the specific infec-
tious agentS-germs- give rise to
them; and this is accomplished by the
use of disinfectants. Having, as l nope,
made this clear.
Any chemical agent which destroys or
I,n1 &c e1lv on nf
as disinfectant. and there are large
number of so called "disinfectants" in
the market which are simply deodOr-
ants and which are entirely untrust-
worthy for the destruction of infectious
material-that is, material containing
living disease germs.
These disease germs belong to the
class of low vegetable organisms-mi-
croscopic plants-known as bacteria,
which as IL rule thrive better in the
darkness than when exposed to day
light. and some OF them are quickly
destroyed by exposure to direct sun
light. In experiments made by me in
1893 it was demonstrated that the chol-
era bacillus is infallibly killed by eX-
posture to direct sunlight for an hour or
two. and the distinguished German
bacteriologist, DR.. Robert Koch, has
shown that the bacillus of consumption
-tubercle bacillus-is destroyed by
! similar exposure in a time varying
from a few minutes TO several hours,
depending upon the thickness of the
layer of material in which it is i'm
| bedded.
AS Il result of this it is evident that
the material coughed up by patients
with consumption and containing tu-
| bercle bacilli in vast numbers is far less
dangerous to the community in regions
where the patient can live out of doors
and where the sun shines nearly every
day in the year.
Some disease germs which are not
killed outright by exposure to the suns
rays are greatly restrained in their de-
velopment. This is true of the bacillus
of typhoid fever. Although it has been
shown by carefully conducted expert
mentS that certain disease germs are
promptly destroyed by the luminous ra-
diations from the sun, and especially
by those at the violet end of the solar
spectrum, it is also true that the heat
rays play an important part in the de-
struction of harmful bacteria.
This is partly due to the fact that
certain disease germs are quickly de-
stroyed by being deprived of all mois-
ture-by desiccation. Thus the germs
| Of f.h Nd - MI inly 1,-
perish when completely dried.
Other germs, however, as those of
typhoid fever, of diphtheria and of
consumption, may retain their vitality
in dried condition for several months.
But the germs of all these diseases are
destroyed by Il comparatively low tenn
pcrature. In experiments which l.
made several years ago | ascertained
that the germs of pneumonia and of
cholera We're killed by exposure for
few minutes to Il temperature of 1875
degrees +.
still lower temperature is effective
if the time of exposure is prolonged.
1t is therefore evident that prolonged
exposure to the direct rays of the sun
would destroy these germs independ-
emily of the diSnfecting power or
| germicidal action of the luminous rays
or the fatal results of desiccation.
Other disease germs require q high
er temperature for their destruction.
| The typhoid bacillus and the bacillus
of diphtheria are killed by exposure
to temperature of 40 degrees f. for
ten minutes. In general it may be
stated that this temperature is fatal
to all the most important disease germs
The facts stated furnish a scientific
basis for practical disinfection, and it
is evident that when sunshine is avail
able no chemical agents are essential
for the destruction of disease germs.
Any article of food or drink which has
been heated for few minutes to some
thing near the boiling point of water
is absolutely safe, so far as any dan
ger from disease germs is concerned,
and any article of clothing, which has
been put through the ordinary opera
tons of the laundry is as safe as if it
had been placed for an hour in an eX-
pensive steam dsinfector or immersed
in Il strong disinfecting solution.
1t will be seen that scientific investi-
cations fully Justify the practice of
good housewives. who at frequent in
tervals expose their blankets and arti-
cles of wooden clothing, which cannot
| be placed in boiling water without in