The Leavenworth weekly times. [volume] (Leavenworth, Kan.) 1870-1880, 1870-11-03

sOtS are nOt SthcIdteu ny inc COIIuptlOu VI Il
The meat; and that the cause of their forma-
lion must be something which is kept away
by cause. But cause will not keep away
must. therefore, exist in the form Of solid l
particles too big to get through the cause.
Nor is one long left in doubt what these sol- |
III particles are; for the blOw-fies, attracted |
by the Odor Of the meat, swarm round the |
vessel. and, urged by a powerful, but in this |
case misleading instinct, lay eggs, out Of |
which maggots are Immediately Matched
upon the gauze. The conclusion, therefore,
is unavoidable-the maggots are not genera
ted by the meat, but the eggs which give rise |
to them are brought through the air by flea"
Almost childishly simple as theses expert |
ments now seem, they were at that time new;
and they are worthy of careful study. Every
piece of experimental work since done, in
relation to this subject, has been shaped
upon the model left by the Italian philos0-
pher.
EXPERIMENTS BY BUTTON AND NEEDHAM.
Led by various theoretical considerations,
Button and Needham doubted the applica-
bility Of Reds hypothesis to the infusOrial
animalculcs, and Neeiham endeavOred to
bring the question to an experimental test.
He argued that if these creatures were pro
duced from germs, the germs must exist
either in the substance infused, or in the
water, or in the superjaoent air. Now, the
vitality Of germs is destroyed by heat; and
hence, il the infusion were bold, carefully
corked, and the vessels containing it again
heated, all germs present would be destroyed.
Consequently, on Reds hypothesis, when
the vessels thus prepared we're set aside to
cool, no animalcules should be developed in
them; whereas If animalcules are not depend
ent upon pre-existing germs, but are gener-
ated from the substance infused, they ought
in time to make their appearance. Needham
found, under the circumstances in which he
made his experiments, that animalcules al
ways did arise in the infusions. In much Of
his work, Needham was associated with Buff
fon, and the result Of their experiments
fitted with the French naturalist's hypOthe
sis of ''Organic molecules" according to
which life is the. indefeasible property of Ger
tain indestrlctible molecules of matter which
exist in all living things, and have inherent
activities by which they are distinguished
from not living matter. Each individual
living organism is formed by their tempo
rary combination. They stand to it in the
relation of the particles Of water to a cascade
or whirlpool, or to the mould into which
the water il poured. The form of the Or
ganism is thus determined by the reaction
between external conditions and the inherent
activities of the organic molecules of which
it is composed; and as the stoppage of whirl-
pool destroys nothing but foam, and leaves
| The molecules of the water with all their in
herent activities intact, SO what We call the
death and putrefaction of an animal or of a
| plant is merely the breaking up of the form,
or manner of association, of its constituent
organic molecules, which are then set free as
| iniusorial animalcules. On this hypothesis,
piece of beef, or handful of hay, is dead
only in limited sense. The beef is dead
OK, and the hay is dead grass; but the cor
ganic molecules" of the beef or of the hay are
not dead, but are ready to manifest their vi
tally as soon as the bovine or herbaceolIs
shrouds in which they are imprisoned are
rent by the macerating action of water.
| NEW ASPECT OF THE QUESTION.
But the great tragedy of science-the slay-
ing of a beautiful hypothesis by an ugly fact
which is SO constantly being enacted under
the eye of philosophers, was played almost
Immediately, for the benefit of Button and
Needl,am. The Able Spallanzani suggested
that Needham's experiments had not been
conducted with sufficient care; and showed
that more prolonged exposure Of the TASKS
to an elevated temperature and a more COM
plete method of closing them, entirely pre-
vented the appearance of animalcules. But
we all too often forget that it is one thing to
refute proposition, and another to prove
the truth of a doctrine that contradicts that
proposition; and the advance of science soon
showed that though Needham might Ike quite
wrong, it did not follow that Slallanzani was
quite right. The discovery of oxygen, and
of some of its relations to the phenomena of
life, opened a new aspect to the question,
and Occasioncd doubts as to what might have
happened to the organic matter of the inii-
sions, or to the oxygen of the air, in Spallan-
zani's experiments. What security was
there that the development of life had not
been checked or prevented by chemical
changes? 1t was necdful to repeat the ex-
pcrinents under conditions which would
make sure that neither the oxygen Of the air
nor the composition of the organic matter
was altered in such manner rs To Interfere
with the existence Of life. Schulze and
Schwann devised means of accomplishing
this, by causing the only air which reached
the infilsions to pass through red-hOt tubes or
through strong sui huric acid. They found
that an infusion SO treated developed no liv-
ing things; but that if it was afterwards ex-
posed to common air, life appeared abun-
dainty. The accuracy Of their experiments
has been by turns affirmed and denied, but,
ment to which the air had been subjected had
destroyed something that was essential to the
development of life in infiisiOns This some
thing might be solid, fluid, or gaseous; that
it consisted of germs remained only an n.y.
1 nf ,toI,:
THE AIR FULL OF LIVING DUST.
The investigations of Schroeder and busch,
in 1854, and of Schroeder alone in 1859,
cleared up this point, by showing that the
exclusion of air from an infusion, by plug
of cotton wool, prevented putrefaction, fer
mentation, and the development of organic
forms. 1t is hard to imagine what the fine
sieve formed by cotton wool could have ex-
cluded, excepting minute solid particles;
but it was reserved for Professor Tyndall to
complete the demonstration by show
ing that ordinary air does contain such par
ticles, and, secondly, that filtration through
cotton wool removes them. 1t has been a
common objection to the doctrine of biogene-
sis, that, If il were true, the air must be thick
with germs-and the abiogenists regard this
as the height Of atsur,lity. Professor Tyn-
dali has proved that ordinary air is no better
than stirabout of excessively minute solid
particles; that these particles are almost
wholly destructible by heat, and that they
are strained off, and the air rendered optic
ally pure, by passing through a layer of cot
/ ton wool.
| SUMMING UP THE ARGUMENT.
| From the whole chain of evidence It is
demonstrable: That fluid eminently fit for
the development of the lowest forms Of life,
but which contains no germs, nor any protein
compound, gives rise to living things in great
abundance, if it is exposed to ordinary air,
while there is no such development If the
air with which it is in contact is mechanic
ally freed from the solid particles which
usually float in it, and which may be made
visible by appropriate means; that the great
majority Of the particles are destfdctible BY
heat, and that some of these are germs, or
living PARTICLES, capable of giving rise to
the same forms of life as those which appear
when the fluid is exposed to unpurlied air;
that incubation of the experimental fluid
with a drop of liquid known to contain living
particles, gives rise to the same phenomena
as exposure to unpurified air; and it is fur
Their certain that these living particles are so
minnie that the assumption Of their suspen-
sion in ordinary air presents not the slightest
difficulty. On the contrary, considering
their lightness, and the wide diffusion of the
L ~ IL