, 1889-07-11
lost TIE PHILOSOPHERS scA

LOST TIE PHILOSOPHERS ScM
'..s....:...bIe Jostrunemts Used by the srod-
s' T-~"hoIoGists.
- might boast that
Ae round the earth in
'n"i. iern psychologists
f.5e !r,----... -.plish far more re-
IEGrGaI.le thIuas. in the world of mat
ter tiI ) are of little worth, but they have
gotten hold of the minds leading strings,
and !&'.> o"nirlycH so ingeniously that
'''d thought. all passions, all delights
have become ryducibIc to mathematical
formula. Mt only have they learned
10 express the poets dream in proSaic
miiiInictrcS, and affairs of the heart in
cold, UuiecliuG dccimaiS, but the inten-
sIty Of "a stroke OF lUmbago and tie rate
oi speed ct a dysPcptic twinge they now
caiou!tte with numerical cxactness.
! 1t Is #m actual fact that ps, cholocists
| will soon have rs complete insight into
| the operations of the mind as have phy-
| siciIns into the functions of the body.
The University of Pennsylvania is the
| pioneer in Introducing the mind measur-
| ing system into America. Professor Cat
| tell brought with him from Germany
some quite remarkable instruments,
principally of his own invention, which
are employed il demonstrating his psy.
Geological lectures. They perform tasks
which materialists have secuted as i'm
possibilities, and strongly tend to prove
that psychology, despite all that has been
said to the contrary, is an exact science
One Of these Instruments will calcu-
late to Il nicely the travelling speed Of an
impression. 4 Chrcnoscope and a vol
taic battery are the principal agents in
the solutioJ of this intricate problem.
BY their means registration is made of
the exact time that clapses between the
occurrence of an act and the sign given
by the subject operated upon that he has
perceived the act. BY 4 process of sub
traction the time is discovered which
passes between the moment at which
the impression reaches consciousness
and the moment when the subject knows
he perceiyes. In this manner mans
rapIdity of perception-hisa ability to sec,
taste, smell, hear or feel-may be accu-
ratcly determined.
For the measurement of sound the sub
Ject forms circuit by applying his hands
to the two poles of the battery. On hear
ing specified noise he instantly breaks
the circuit. Immediately the hand of
the chronoscoPe stops short, Indicating
III thouSandthS of a second the time that
has elapsed between the occurrence of
the sound and the breaking of the cir
cult. On tEis basis mans perceptiye
power is calculated.
BY analogous means the comparative
swiftness of sight is measured. Profes-
toll laas
that onc-tenth of = second suffices for
him to perceive color, oce-eighth of
second is necessary for the perception of
4 letter. anu one-seVenth of n second for
Il word.
The strength of Il persons memory is
determined by a complicated machine
which presents TO the eye at intervals of
a second flashes of light OF varying de-
grees of intensity. The more subtle is a
mans power of recognition the more
readily he distinguishes one light spot
from another, and the longer he retains
his impressions. In this way the minds
concentration and retentiyeness are
measured III fractions of second.
By means of the gravity chronometer
the comparative case or difficulty with
which letters or words may bo perceived
Is demonstrated In . sliding screen
moved by electricity Il slit five inches
wide is inserted, behind which an object
Is exposed 10 view for an infinitessimaI
space OF time.
In 4 series of experiments with the
letters of the alphabet the time Of expos
ure was one-thOusandth of a second.
That of go trials W was seen 241 times,
while Z appeared seen but G3 times. OF
other capital letters q, n, D and Il
ranked next in succession after in the
quicknes5 with which they were per-
ceived, while V, F, U and j were OBJ
served only with great difficulty. OF
the small letters sd" is the most easily
recognized, and SIS" least easily, the for
mer being perceived three times as often
as the latter.
If the several colors are exposed to
view il like manner for fraction of
second orange and yellow will be most
clearly perceived. Blue, red and green
follow in tho order named, violet being
the least easily recognized and requiring
two or three times as long exposure as
the bright coloFs. This device serves to
measure the range or complexity of the.
mind. Philadelphia Record.