t pressure upon the keys closed two
electric circuits and, releasing the keys, opened them, and both the
closing and the opening were recorded upon the smoked paper by means of
the markers. And, finally, in order to ascertain the time relations of
all these processes, a time-marker indicated the time in fifth-seconds
upon the revolving kymograph record. The time-curve was recorded just
below the other curves.

Of the curves[P] thus obtained under the most equable conditions
possible, we publish seven which show the great general uniformity of
the tests made upon the horse with those made in the laboratory. The
role of questioner was undertaken at different times by Mr. Schillings
and the students of philosophy, Messrs. von Allesch, Chaym and K. Zoege
von Manteuffel. To all of them I am greatly indebted for their unselfish
services in these laborious tests. The experiments with von Allesch and
Chaym, who were among the most suitable of my subjects, were conducted
absolutely without knowledge on their part of the nature of the
phenomena which I was observing. Neither of them knew anything about the
expressive movements in which they were unconsciously indulging, and
furthermore, since they kept their heads bowed during the entire course
of these experiments, they did not perceive what it was that I was
observing. It is interesting to note that Chaym on the occasion of his
only visit to the horse, immediately received a number of correct
responses. Without a doubt von Allesch would have met with equal
success. The other two subjects (von M. and Sch.) went through this
series of tests, possessing some knowledge of the nature of the
movements involved. Conditions were such that they (and especially Mr.
Schillings) could not be prevented from obtaining some knowledge of the
essentials, at least. However, it would be wrong to suppose that for
this reason the results were more favorable, owing, mayhap, to voluntary
efforts on the part of the subject. The contrary was true. The two
subjects who had no knowledge of the character of the reactions upon
which my responses depended, retained their normal habits, unchanged,
throughout the series,--whereas the last-named two, afraid lest their
knowledge vitiate the result, lost more and more of their power of
concentration and within a short time were in a condition of tense
inhibition, which is all the more conceivable, since they had had no
psychological training whatever.[Q]