The Dallas daily herald. [volume] (Dallas, Tex.) 1873-1887, 1880-09-17
MEASUREMENT OF lHOUGHT.
A Wonderful ention-some His y
Interesting Tests.

Interesting Tests.
In the course of Prof. Bankers remarks
before the ecent session of the American as
ISOLATION for the advancement of sience in
Boston no said;
An important fact concerning nervous &C.
ton is that Its amount may be measured by
tho quantity of blood consumed in its per.
Torrance. DR.. Mosso, of Turin, has devised
nm air apparatus called the plethysmogrsph--
drawings of which were exhibited at the
London apparatus exhibition Of lS76-de-
signed for measuring the volume OF
an organ. The forearm, for
example, being the organ to be expert
mentsd on, is placed in cylinder of water
and tightly inclosed. A rubber tube con-
meets the interior of the cylinder with the
recording apparatus. With the electric cir
cult by which the stimuous WAS applied to
produce contraction were two keys, one OF
WI ich was dummy. 1t was noticed that,
after using the active key several times, pro-
ducipg varying current 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
To test further the effect of mental action,
DR.. PAglia whose arm was in thu apparatus,
was requested to multiply 267 by 8, mentally.
and to make a sign when he had finished.
The recorded curve showed very distinctly
how much more blood the brain took to
perform the operation. Hence the plelhys-
mograph is capable of measuring the rela-
tive amount of mental power required by diff
ferent persons TO work out the same mental
problem. Indeed, Mr. Gaskell suggests the
use of this instrument in the examination
room to find out, in addition to the
amount Of knowledge man POSSESSES g.,
how much effort 1t causes him to
produce any particular result of brain
work. DR.. Nosso relates that while
the apparatus was set up in his room in
Turin, classical man came in to sec him.
he looked very contemptuously upon it, and
asked Of what use it could be, saying that it
couldn't do anybody any good Dr. Mosso
replied; "Well, now, can tell yuu by that
whether you can read Greek rs easily as you
can Latin" AS the clsssicist would not be.
lleve that, his own arm was put into the
apparatus and he was given Latin book to
read. A very slight sinking of the curve
WAS the result. The Latin book was then
taken away and Greek book was given
him. This produced Immediately II much
deeper curve. He had asserted before
that II was quite as easy for him to read
Greek as Latin, and that there was no diff
Guilty in doing either, DR.. Mosso, however,
was able to show him that he was laboring
under delusiol Again, this apparatus is
SO sensitive as to DO useful for ascertaining
how much person 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 had passed in the room
that he had been absolutely unconscious;
and yet every little movement in the
room, such AS the slamming of door, the
barking of a dog, and even the knock. down
of bit of glass, were all marked on the
curves. Sometimes he moved his lips and
gave other evidences that no was dreaming;
they were all recorded on the curve, the
amount of blood required Cor dreaming di-
minishing that in the extremities. The emo
tons, too, left record When only student
came into the room little or no effect
appeared in the curve. But when Professor
Ludwig himself came in, the arteries in the
arm of the person in the apparatus
contracted quite as strongly rs upon very
decided electrical stimulation.