The times. [volume] (Washington [D.C.]) 1897-1901, 1901-01-27

third day an incalculable number of bill
| lions. whose weight would be in the proxi-
| nifty of 1880 tons!
But fortunately for our welfare, nature
| by various means renders the possibility
| of such happening entirely beyond the
slightest chance of realization. her great
| est barrier being the lack of an adequate
food supply.
The distribution in nature of bacteria
is well nigh universal. occurring as they
do in the air We breathe the water and
! milk we drink, upon the exposed surfaces
of man and animals and in their intes-
final tracts. and in the soil to a depth of
about nine feet But it has been noted
that at very high attitudes and in glacier
ice none exists. while In the Arctic regions
and at sea far from land their numbers
are very few.
The conditions governing their growth
involve many complex problems but
few of the chief factors concerned are
moisture, air. food, temperature, and
light All bacteria must have moisture.
else they die sooner or later depending
upon the hardness of the species. and
none can multiply without 1t. A supply
of air is by no means essential to all
germs. To some 1t is absolutely necessary.
and such germs are called aerobes. To
others air is wholly detrimental. and they
constitute the anaerobes, while to the ma
jority of bacteria air supply is a matter
of indifference. and In consequence they
are grouped under the term facutative
anaerobes.
The food supply of many consists of
dead animal and vegetable materials, a
few require living tissues. while a small
number can exist wholly upon mineral
salts or even the nitrogen of the air. The
lowest temperature at which some bac-
terra can multiply is the freezing point
of water and the highest 40 degrees Fahr-
enheit. However. the average range of
temperature suitable to the majority lies
between 90 and 10i degrees Fahrenheit,
IS 20 degrees Fahrenheit being the most
suitable for the growth of disease -produc-
ing germs. Light, ordinarily dffused day
light, or It's absence is a matter of no mo-
ment to most germs, whereas direct sun
light is destroyer of all bacteria.
The study of the life histories of these
diminutive plants eXcites the wonder of
those who make observations upon them.
1t is truly marvellous to know that these
bacteria can accomplish in their short
lives of possibly few hours or days feats
which would battle the cleverest of chem
lists if given years of life time to work
upon. They give to the farmer the good
quality of his crops. to the dairyman SUI
perior butter and cheese; they assist in
large measure in freeing our rivers and
lakes from harmful pollutions. Here 1t
should be strongly emphasized that those
bacteria which cause disease are only of
few species, all others contributing to
our welfare in countless ways.
Quite as astonishing is the discovery
that within the root knobs of peas and
beans live bacteria which by splitting I'd
mineral salts containing nitrogen, and by
absorbing nitrogen from the air, give IL
over to the plant so that 1t is enabled to
grow luxuriantly. whereas. without their
presence the tiller of the soil might fer
tilize the ground in vain 1t is quite DOS
sible that not alone peas and beans, but
all grasses and plants and trees depend
upon the presence of such germs for their
very existence. which In turn supply man
and animals with their means of exist
ence. Hence We see that these nitrifying
bacteria, as they are called, IL swept out
of existence would be the cause of cessa-
tfon of all life upon the globe. And argu-
ing backward. one prominent authority
states II as his belief that the first of all
life on this earth We're those lowiy forms
of plants which only required the nitrogen
of air or salts to enable them to multiply.
Limiting observation now to the sphere
of medicine. it will be readily perceived
that the presence of bacterial life in a
casuatiye relation to disease is an object
of paramount regard.f The following para
graphs will briefly treat of the diseases as
ISOLATED with micro-organisms and the
common modes of infection in each, the
chain of events subsequent to an infec-
ton, and the possibilities of protection or
cure by means of substances elaborated in
the body of an individual or animal re-
Gently recovered from an infectious dis
ase:
ANTHRAX.-A disease chiefly of cattle
and sheep. occasionally of man, is caused
by the Bacillus anthracis, discovered in
1880 by Pollender and Dayaine. 1t en-
tiers the body through abrasions of the
skin. by Inhalation Of the spores, or seeds
into the lungs, or by swallowing infected
material.
LEPROSY.-This disease is caused by A
bacillus known as Bacillus leprae. which
was discovered by Hansen In 1879 It is
doubtful If it has been grown outside the
body. 1t is supposed to enter by abraslons
of the skin. but it is very feebly contag-
ious Notwithstanding popular ideas as TO |
its supposedly highly contagious: nature.
TUBERCULOSIS forms of this dis
ease, among which is ordinary consump,
ton. are caused by a bacillus closely re-
sembling that of leprosy. 1t was dlscov- !
cred by Koch in 1Ss0-S2, and named Bacil- |
lus tuberculosis. The ways Of Infection are |
iives, drinking infected cows milk. or eat |
ing infected meat
TYPHOID FEFER-A disease of hu |
man beings only. Eberth in 1880 discovered
the germ causing 1t and called it Bacillus
typhosus. II gains entrance to our bodies
chiefly in the milk and water we drink. |
which comes from infected sources; a |
rarer method is by inhalation of infected
lirs
DIPHTHERIA.-A disease of human
beings chiefly 1t is caused by IA bacillus
which was described in 1854 by Klebs
and Loeflier. and Is known as Bacillus
iiphtheriae, or klebs-LoefIler bacillus. Its
mode of entry is BY irhaling infected air.
or by drinking or eating infected milk or
food.
CHOLERA-Thisd disease is peculiar to
human beings. Its native home Is on the