The interior journal. [volume] (Stanford, Ky.) 1872-1881, 1873-02-07
Popular Fallacies.

TWO large NOiumG WIN ~ sccouh' VI
whatheconside TO be Vulgar Errors
--"Pseudodoxia Epidemica"-and al
though modern science has done much to
diffuse sound knowledge in regard to the
phenomena around US, yet popular fall
lacies have not, ss yetquite disappeared.
Even our textbooks Of popular science,
and many Of our socalled scientific pa
pers, continue to propagate and perpetu-
ate mistakes which may he Chased with
the vulgar errors of DIR. Browne.
Thus, nothing Is more common than to
hear of the tubular character Of hair; in
deed, almost every one that we meet
will, If asked, tell US that the hairs Of our
head are very 6ne tubes. And yet every
hair is good solid cylinder fact that
has been published hundreds Of times,
but which seems TO have no effect upon
the popular belief. 1t is true that hair
when examined under the microscope,
looks something like tube; but then so
does solid metallic wire-s fine needle,
for example. That which gives rise to
the tubular appearance is simply the
bright line which Is always seen on every
cylinder stove pipe, for example, or
even a common black-lead pencil.
When we take the hair, however, and,
having cut Q slice Of the end, examine
this slice, we End that il is not q ring,
as it would be If cut from the end Of a
tube, but cold disk.
Another singular idea, which has
gained very general ground, is that the
moons of Jupiter can be seen in look
ing glass; and If some bright night, We
try the experiment, we shall actually see
Jupiter in the looking glass, accompanied
by very faint star which constantly
maintains the same distance from the
planet. Further examination will show
US that every bright star presents the
sameappearance; and five reflect little
upon the phenomenon, We shall see that the
so-called moon is only the faint image Of
the star or planet reflected from the sur
face of the glass while the bright image
reflected from the surface Of the mercury
is what we call the star itself. A lamp
or candle held before thick mirror will
present the same appearance. Simple |
though the explanation be, however, there
are few errors that have taken deeper
hold on the minds Of the pseudo-scientifc
than this.
Amongst popular fallscies, q promi'
nent place must be given to those which
arise from the actual deception of the
senses; for neither our eyesight nor our
sense of touch is to be absolutely de-
pended upon. Thus the beautiful phe-
nomenon known as "the sun draws
water" Is simply by the rays Of the sun
piercing arift in the clouds, aud rendered
more intense by the prevailing gloom.
Few people would believe that actual
measurement of the sun and moon when |
near the horizon at rising or setting,
would fail to show that they are then
much larger than at other times; and
yet, allowing for the difference caused by |
refraction, and which is too slight to be
measured by any but the finest instru-
ments, actual measurement does show
that not only their real, but their appar-
ent sizes, are precisely the same at all
times.
Another fallacy which is very prev
alent is that every drop OF water contains
millions of snimalcules and that every
pebble, indeed every fragment of solid
matter ON the face Of the globe is peopled
with myriads of these small creatures.
For this belief there is, however, no foun-
dation whatever. So far as animalcules
are concerned, most pebbles and frag-
ments Of rock are barren deserts, especi-
ally when dry; and good spring water is,
90 far rs animal life is concerned, liquid
waste. A few stray animalcules, may
occasionally be found in water that we
drink; but If 1t is "flled" with animal
cules, it is certainly not fit for human use.
either as drink or in the preparation Of
food.
But while most of the fallacies which
we have mentioned are due to simple
ignorance, there is another class which
is based upon a sort Of quasi-scientifc in
formation, md which are far more dr.
gerous. A good example Of these is the
opinion generally held by halftaught
chemists, that il is to the silicious coating
of the grasses and cereals that the plants
owe their power Of standing upright
in other words, that it is to this that they
owe their stiffness. This opinion has been
30 firmly held by many, that they have
advised the addition Of silica to land for
the purpose of giving stiffness to the
straw and thus preventing the lodging
pfthegrain: Now when we learn that
almost all soil consists OF at least one-half
silica, we shall see the absurdity of such
sdvice The truth is, that the stiffness
Of straw is not due to the silica at all;
for chemists have dissolved the silica by
means Of hydroauoric acid and removed
it completely from the vegetable stem,
without impairing the stiffness ofthe lat
ter.-Iadustrial Monthly.
Value Of Salt.