Knoxville daily chronicle. [volume] (Knoxville, Tenn.) 1870-1882, 1880-09-19
OF THOUGHT.
A Wonderful Invention-Some High
ly Interesting Tets.

In the course of Prof Barker's remarks
before the recent session Of the American
association tor the advancement of sci
ence in Boston lie said:
An important fact concerning nervous
action is that its amount may be measured
by the quantity Of blood consumed in
its performance. DR.. Mosso, of Turin, has
devised an air apparatus called the
Observation-Disclosures Of which were
exhibited at the London apparatus eX
hibition of 1876 designed for m easureing
the volume of an organ. The forearm,
for example, being the organ to be eX.
perimented on, is placed in cylinder Of
water and tightly inclosed A rubber
tube connects the interior of the cylinder
with the recording apparatus. With the
electric circuit by which the stimnlous
was applied to produce contraction were
two keys, one of which was dulmy. 1t
was noticed that, after using the active
key several times, producing varying cur
rent strengths, the curve sank as before
on pressing down the inactive key. Since
no real effect was produced, the result was
caused solely by the Imagination, blood
passing from the body to the brain in the
act.
~ I6SG LIE CDtCt VI l41SAlIe'i HSIiOh
Dr. Pagliani, whose arm was in the ap
paratus, was requested to multiply 267 by
8, mentally. and to make sign when he
had finished. The recorded curve showed
very distinctly how much more blood the
brain took to perform the operation.
Hence the plethysmograph is capable OF
measuring the relative amount of mental
power required by different persons to
work out the same mental problem In
deed, Mr.. Gaskell suggests the use OF his
| instrument in the examination room to
| find out, in addition to the amount of
knowledge Juan possesses, how much
effort it causes him to produce any par
ticular result of brain>wOrk. MOsso relates
that while the apparatus was set up in his
room in Turin, a classical man came in to
see him He looked very contemptuOusly
upon it, and asked of what use it could be,
saying that it couldn't do anybody any
good. DIR. Mosso replied: "Well, now,
[ can tell you by that whether yon can
read Greek as easily as you can Latin
AS the classicist would not believe 1t, his
own arm was put into the apparatus and
he was given Latin book to read a
very slight sinking of sthe curve was the
result The Latin book was then taken
away and Greek book was given him.
lDlS pfOuuCcU immediately lnuCll uttp'
er curve. He had asserted before that
it was quite as easy for him to read Greek
as Latin, and that there was no difficulty
in doing either. DR.. Mosso, however, was
able to show him that he was laboring TN
der diffusion. Again, this apparatus is
so sensitive is to be useful for ascertain
ing how much prison is dreaming.
When DR.. Pagliani went to sleep in the
apparatus, the effect upon the resulting
| curve was very marked indeed He said
afterward that he had been in sound
sleep and remembered nothing Of what
passed in the room-that he had been alb
solutely unconscious; and yet every Ii tie
| mounted in the room, suca as this slam.
ming of door, the barking Of n dog,
| and even the knock down of bit of glass.
| were all marked on the curves. Some
times he moved his lips and gave other
evidences that he was dreaming; they were
all recorded on the curve the amount OF
blood for dreaming diminishing that in
extremities. The emotions, too, left a
record " hen only q student came into
the room, little or no effect appeared in
the curve. But when Prof. Lud wig
himself came in. the arteries in the arm of
the person in the apparatus contracted
Quite as strongly as upon n very decide
! electrical stimulation.