The free lance. (Fredericksburg, Va.) 1885-1926, 1902-05-01
HEAT AND DISEASE.
sHE SUMS RAYS ARE FATAL TO MANY
SPECIES OF GERMS.

Are Destroyed.
Sunlight is fatal to some OF the Iovver
forms OF living things, including GER
tain disease germs which are the cause
OF some OF the most fatal infectious
diseases that afiiict the human race.
In fact, the greatest disinfectant I'm ma
turc is light. or. TO bee more exact. the
IadlatiOns 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 (bacillus) which
produces diphtheria 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
tent with diphtheria is infectious ma
terial. In cholera and I'm typhoid fever
the discharges from the bowels con
tain the germ ana are consequently in
fictitious material.
prevent the extension of infectious dis
eases by destroying the specific infec-
iOus -germs-which give rise 70
them; and this is accomplished by the
use of disinfectants. Having, as nope.
made this clear.
Any chemical agent which destroys or
masks bad Odors is commonly spoken of
as disirIectant, and there are a large
number Of so called "disinfectants" I'm
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 ms 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
1899 II 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
bacterioloSist. DIR. Robert Koch. has
shown that the bacillus Of consumption
-tuberclc bacillus-is destroyed by
similar exposure i'm time varying
from few minutes To several hours.
depending upon the thickness of the
layer OF material in which It Is i'm
beddcd.
As Il result of this IL 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 I'm the year.
Some disease germs which are not
Killed outright by exposure TO the suns
rays are greatly restrained I'm their de-
velopment. This is true OF the bacillus
of typhoid fever Although # 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 Mt the violet end of the solar
spectrum, IL 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-
stroycd by being deprived OF all mois-
ture-by desiccation. Thus the germs
or cholera and of pneumonia quickly
perish when completely dried.
Other germs, however. as those Of
typhoid fever. Of diphtheria and of
may retain their vitality
In dried condition for several months. |
But the germs of all these diseases are
destroyed by n comparatively low tenn
perature. In experiments which | |
made several years ago / ascertained /
that the germs of pneumonia and of |
cholera were killed by exposure for n
few minutes 10 a temperature OF 126 |
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 disinfecting power or |
germicidal action of the luminous rays |
or the fatal results OF dcsiccation.
Other disease germs require high |
er temperature for their destruction. |
The typhoid bacillus and the bacillus |
or diphtheria are killed by exposure |
to temperature of 40 degrees +. 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 scientific |
basis for practical disinfectiOn. and 1t |
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 1t !
had been placed for an hour in an ex-
pensive steam dsinfector or immersed
In strong disinfecting solution.
II will be seen that scientific inyesti-
cations fully justify the practice OF
good housewives, who AT frequent in
farvolS axnnSa fhafr hloptotS onI o.tf