96 PSYCIIOLOOY. 



Buccola, and Beuuuis. Tliej are slow, averaging about 

 half a second (cf. Beannis, lieclieiches exp. sur I'Activite 

 Oerc'brale, 1884, p. 49 ft".). 



It Avill be observed that sound is more promptly reacted 

 on than either sight or touch. Taste and smell are slower 

 than either. One individual, who reacted to touch upon 

 the tip of the tongue in 0".125, took 0".S)\)'d to react upon 

 the taste of quinine applied to the same spot. In another, 

 upon the base of the tongue, the reaction to touch being 

 ".141, that to sugar was 0''.552 (Yintschgau, quoted by 

 Buccola, p. 103). Buccola found the reaction to odors to 

 A'ary from 0".334 to 0".G81, according to the perfume used 

 and the individual. 



The intetisity of the signal makes a difference. The in- 

 tenser the stimulus the shorter the time. Herzen (Grund- 

 linien eiuer allgem. Psychophysiologie, p. 101) compared 

 the reaction from a corn on the toe with that from the skin 

 of the hand of the same subject. The two places were 

 stimulated simultaneously, and the subject tried to react 

 simultaneously with both hand and foot, but the foot always 

 went quickest. When the sound skin of the foot was 

 touched instead of the corn, it was the hand which always 

 reacted first. Wundt tries to show that when the signal is 

 made barely perceptible, the time is probably the same in 

 all the senses, namely, about 0.332" (Physiol. Psych., 2d 

 ed., II. 224). 



Where the signal is of touch, the place to which it is 

 applied makes a difference in the resultant reaction-time. 

 G. S. Hall and V. Kries' found (Archiv f. Anat. u. Physiol., 

 1879) that when the finger-tip was the place the reaction 

 was shorter than when the middle of the upper arm was 

 used, in spite of the greater length of nerve-trunk to be 

 traversed in the latter case. This discovery invalidates the 

 measurements of the rapidity of transmission of the current 

 in human nerves, for they are all based on the method of 

 comparing reaction-times from places near the root and 

 near the extremity of a limb. The same observers found 

 that signals seen by the periphery of the retina gave longer 

 times than the same signals seen by direct vision. 



The season makes a difference, the time being some hun- 



