Public ledger. [volume] (Memphis, Tenn.) 1865-1893, 1872-07-12
POPULAR FALLACIES.


large volumes with an account of wha
he conceived to be Vulgar Errors, y
"Pseudodoxia Epidemica," and althoug
modern science has done much to dii
fuse sound knowledge in regard to th
phenomena around US, yet popular fal
lacies have not, as yet, quite disappear
ed.a Even our textbooks of popula
science, and many of our so.called sci
entifc papers, continue to propagate
and perpetuate mistakes which ma,
we'll be classed with the vulgar errors
of DR.. Browne. Thus, nothing is NOR,
common than to hear of the tubula
character of hair; indeed, almost ever!
one whom we meet will, if asked, tell u
that the hairs of our head are fin,
tubes. And yet every hair is goot
solid CYLINDER fact which has beer
published hundreds of times, but which
seems to have no effect upon the popu
lar belief 1t is true that hair, wher
examined under the microscope, look
something like a tube; but then so does
q solid metallic wire-a fine needle fol
example. That which gives rise to thu
tubular appearance is simply the bright
line which is seen on every cylinder
stovepipe, for example, or even a com
mon black lead pencil. When we take
the hair, however, and having cut slict
off the end, examine this slice, we find
that it is not ring, as it would be if cut
from the end of tube, but solid disk
Another singular idea, which has
gained very general ground, is that
the moons Of Jupiter can be seen in q
looking-glass; and if, some bright night
we try the experiment, we shall actually
see Jupiter in the looking glass, accom-
panied by very faint star, which con.
stantly maintains the same distance
from the planet. Further examination
will show us that every bright star pre-
sents the same appearance; and, if we
reflect little upon the phenomenon, we
shall see that the so-called moon is only
the faint image Of the star or planet re-
hected from the surface 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 mirror will present precisely
the same appearance. Simple though
the explanation be, however, there are
few errors that have taken deeper hold
on the minds Of the pseudo-scientiic
than this. M sl.H
Amongst the popular fallacies, 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 depen-
ded upon. Thus, the beautiful phe-
nomena known as the sun drawing wa
ter " is caused simply by the rays Of the
sun piercing a rift in the clouds, and
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 set
ting, 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 Instruments, actual measurement
does show that not only their real but
their apparent sizes are precisely the
same at all times.
Another fallacy which is very preva-
lent is that every drop of water contains
millions of animalcules, and that every
pebble, indeed every fragment Of solid
matter on the face of the globe, is peo-
pied with myriads of these small crea-
lures. For this belief there is, however,
no foundation,whatever. So far as ami
are concerned, most pebbles
and fragments of rock are barren deserts,
when dry; and good spring
water is, so far as animal life is con-
cerned, a liquid waste. A few stray
may occasionally be found
n the water that we drink; but if it is
filled " with animalcules, it is certainly
lot fit for human use, either as drink or
n the preparation of food.
But, while most of the fallacies which |
We have mentioned are due to simple |
ignorance, there Is another class which |
$ based upon sort of quasi-scientiic |
9and which are far more
dangerous. A good example of these
s the opinion generally held by half
aught chemists, that it is to the sila-
'eous coating of the grasses and cereals
hat these plants owe their power of
tanding upright in other words, that it
5 to this that they owe their stiffness.
The opinion has been so firmly held by
many, that they have advised the addi-
ion of silica to land for the purpose of
living stiffness to the straw, and thus
preventing the lodging of the grain.
Jow, when we learn that almost all soil
onsists Of at least one-half silica, we
hall see the absurdity of such advice.
he truth is, that the stiffness of straw
} not due to the silica at all; for chem
,ts have dissolved the silica by means
{ hydronuoric acid, and removed il
from the vegetable stem
-ithout impairing the stiffness of the
ltter.