LABORATORY TESTS 117 



questioner when working with the horse. Three levers 

 were attached to his head in such a way that every move- 

 ment backward or forward would act upon the first 

 lever, every movement to the right or left would move 

 the second, and every movement of the head upward or 

 downward would be recorded by the third. With regard 

 to the sensitivity of the machine, micrometric determina- 

 tion showed that when the subject was properly installed, 

 movements through so small a distance as xV millimeter 

 could be accurately ascertained. The subject was care- 

 fully instructed to remain as quiet as possible, but with- 

 out constraint. Voluntary movements were thus ob- 

 viated. But the question arose : were not the involuntary 

 movements thus suffering a loss ? — And it was upon them 

 that we were experimenting. The question cannot be 

 put aside summarily, but experience taught us that the 

 movements in question, nevertheless, did appear quite 

 effectually, if one could have the right kind of subjects 

 at one's command. We need hardly mention that besides 

 the two persons immediately concerned — I, myself, at- 

 tended to the apparatus — there was no one else present, 

 and that the subject was not allowed to see the curves 

 produced on the kymograph. Besides the registration 

 of the head-movements, I also undertook to register the 

 respiratory-movements of the subject. This was done 

 by means of the so-called pneumograph, attached to 

 which was a lever recording the thoracic expansion and 

 contraction. This was for the purpose of ascertaining 

 the relationship, which might eventually be found to 

 exist, between the release of psychic tension, on the one 

 hand, and respiration, on the other. 



The subject was now told to think of some number, 

 which, of course,, was unknown to me. At a given 



