THE PERCEPTION OF TIME. 621 



And here again we liav^e an analogy witli space. The 

 earliest form of distinct space-perception is undoubtedly 

 that of a movement over some one of our sensitive surfaces, 

 and this movement is originally given as a simple whole of 

 feeling, and is only decomposed into its elements — succes- 

 sive positions successively occupied by the moving body — 

 when our education in discrimination is much advanced. 



muscles to have occurred. In reproducing intervals ourselves we try to 

 make our feelings of this sort just what they were when we passively heard 

 the interval. These feelings by themselves, however, can only be used 

 when the intervals are very short, for the tension anticipatory of the terminal 

 stimulus naturally reaches its maximum very soon. With longer intervals 

 we take the feeling of our inspirations and expirations into account. With our 

 expirations all the other muscular tensions in our body undergo a rhythmi- 

 cal decrease; with our inspirations the reverse takes place. When, there- 

 fore, we note a time-interval of several seconds with intent to reproduce it, 

 what we seek is to make the earlier and later interval agree in the number 

 and amount of these respiratory changes combined with sense-orgaa 

 adjustments with which they are filled. Mllnsterberg has studied care- 

 fully in his own case the variations of the respiratory factor. They are 

 many ; but he sums up his experience by skying that whether he meas- 

 ured by inspirations that were divided by momentary pauses into six parts, 

 or by inspirations that were continuous ; v;hether with sensory tension dur- 

 ing in.spiration and relaxation during expiration, or by tension during both 

 inspiration and expiration, separated by a sudden interpolated relaxation ; 

 whether with special notice taken of the cephalic tensions, or of those in 

 the trunk and shoulders, in all cases alike and without exception he in- 

 voluntarily endeavored, whenever he compared two times or tried to make 

 one the same as the other, to get exactly the same respiratory conditions 

 and conditions of tension, all the subjective conditions, in short, exactly i\iQ 

 same during the second interval as they were during the first. Milnsterberg 

 corroborated his subjective observations by experiments. Tlie observer of 

 the time had to reproduce as exactly as possible an interval between two 

 sharp sounds given him by an assistant. The only condition imposed upon 

 him was that he should not modify his breathing for the purposes of 

 measurement. It was then found that when the assistant broke in at 

 random with his signals, the judgment of the observer was vastly less 

 accurate than when the assistant carefully watched the observer's breathing 

 and made both the beginning of the time given him and that of the time 

 which he was to give coincide with identical phases thereof. — Finally, 

 Milnsterberg with great plausibility tries to explain the discrepancies bs- 

 tween the results of Vierordt, Estel, Mehner, Glass, etc., as due to the fact 

 that they did not all use tlie same measure. Some breathe a little faster, 

 some a little slower. Some break their inspirations into two parts, some 

 do not, etc. The coincidence of the objective times measured with definite 

 natural phases of breathing would very easily give periodical maxima of 

 facility in measuring accurately. 



