, 1879-06-08
SENSATION, AND sEN8IFER0US ORGANS

SENSATION, AND sEN81FER0US ORGANS.
In the Nineteenth Century for April Prof.
HUXLEY instituted IN inquiry into the nature
of the phenomenon we call sensation, and
the structure OF the sensiferous organs.
These have been, from the time Of AR1sToTLE,
fruitful subjects Of speculation. The ques-
ton which has perple1ed philosophers is,
"How is the relation between the material
and the immateriM phenomena to be con-
ceived?" One school has answered that
"An immaterial substance Of mind existed,
and that it was affected by the mode Of
motion of the sensorium in such way as to
give rise to sensations" 4 second school
has believed that The sensation is direct
effect of the mode of motion of the sen-
sorium, brought about without the interven-
ton Of any substance Of mind" The third
school has declared that "The sensation is
neither directly NOT Indirectly an effect Of
the mode Of motion Of the sensorium, but
that it has an independent CAUSE"
Prof. HUXLEY, being materialist himself,
naturally inclines to the second hypothesis,
but he does SO cautiously and with reserva-
tions. He admits that none Of the hypoth-
eses is capable Of even an approximation to
demonstration 4 sensation, he says, Is an
intuition,-a part of immediate knowledge.
As such it is an ultimate fact, and ine1phca-
BILE, AL that We can hope to find out about
it-and that indeed is worth finding QUITS
its relation to other natural facts. But when
rES hoo hooY1 mazda
Prof. HUXLEY does not admit that it Is anoth-
or illustration OF the emptiness and useless
ness Of metaphysical discussions. It is some
thing to know how human understan dings
are limited. 1t is true that all mankind are
ignorant in regard to this mysterious rela-
ton, aud that from the nature Of the caso
they never can know the precise facts about
it but all mankind unfortunately does not
know that it is ignorant. There are many
who believe they know more about material
than they do about immaterih ex1stences.
g" And it." remarks the Professor, in conclu-
sion, as wise man has assured us, the
knowledge Of what we don't know is the
next best thing to the knowledge Of what
we do know, this brief excursion into the
province Of philosophy has been highly profit
able"
The theory OF sensation, Prot. HUXLEY
says, is very much where HARTLEY, led by
hint Of. Sir Isaac NEw1oH's, left it IN his
+" Observations on Man," etc. The whole
matter is concisely stated in the following
passages of this book: /;
''E1ternal objects impressed upon the senses
occasion, first on the nerves which they are In
pressed. and then on the brain, vibrations OF the
small and, as we may say, infnitesimal medullary
particles.
''These vibrations are motions backwards and
forwards OF the small particles; Of the same Kind
with the oscillations Of pendulums and tbs t1em-
blinss Of the particles Of sounding bodies. They
must be conceived to be exceedingly short and
small. SO as not to have the least efficacy to dis
turb or move the whole bodies Of tho nerves or
brain.
stThe white medullary substance Of tho brain is
also the immediate instrument BY which ideas are
presented to the mind; Or, in other WORDS "hat-
ever changes are made in this substance, CORE
spending changes are made In our ideas; and vice
versa"
!: If for .t white medullary substance " in the
last paragraph gray cellular Substance ha.