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[Entered at the Post-Offiee of New York, N.Y., as Second-Class Matter.] 



A WEEKLY NEWSPAPER OF ALL THE ARTS AND SCIENCES. 



Eighth Teab. 

 Vol. XVI. No. 395. 



NEW YORK, August 29, 1890. 



Single Copies, Ten Cents. 

 $3.50 Pee Yeab, in Advance. 



THE TIME-RELATIONS OF MENTAL PHENOMENA. 



[Continued from p. 101.] 



Conditions Affecting Simple Re-action Times. 



Referring to the accompanying table for a general view 

 of the time-relations of simple re-actions, we may pass at once 

 to the topic of greatest interest, viz., the influences by which 

 they are quickened or retarded. These may be considered as 

 (A) objective, or affecting the conditions of the experiment, 

 and {B) subjective, affecting the attitude of the re-actor. 



(-4., 1) The Nature of the Impression. The distinctive 



necessitating a precise accommodation, — a condition not 

 always supplied in the above experiments. This view is 

 strengthened by the shortening in the re-action time (by 36(T 

 for Exner, by 24^ for v. Wittich) when the eye is stimu- 

 lated electrically. In re-acting to a temperature sensation, 

 care must be taken not to re-act to the sensation of contact 

 with the skin. Where this has been done it has been found 

 tiiat the re-action to the sensations of temperature is longer 

 than to contact, and that the re-action to heat is longer than 

 to cold. Thus, Vintschgau and Steinach re-act to a pressure 

 on various points of the head in 109(>, to, a sensation of cold 



Table of Simple Re-action Times. 



Nature of Sense-Impression. 



xr 



XII 

 XIII 



XIV 



XV 



XVI 



XVII 



XVIII 



XX 

 XXI 

 XXII 



Visual (various kinds) 



Tactile " " 



Auditory " " 



Temperature (cold) 



*' (warm) 



Light of intenalty I 



II 



Ill 



" IV. 



" " V. 



VI 



" VII 



Touch (electric shock) 



Scund (low) 



Sound 



I ( Average of weak and loud 



,Sound-< 



1 ( sound 



jSound 



Touch (electric shock in forearm). 



Average of many 185 



Vintschgau I 

 Steinach J 

 Berger ■) 



& Y 



Cattell I 



Exner. 



Wundt. 



Berger ) 



& 

 Cattell J 



Wundt. 

 Muns erberg 



Av. ' 161 Average of all parts of body. 



The intensity in terras of a common unit 

 were as 7, 33, 12.3, 315, 1000, the two high- 

 est intensities not being determinable. 



By openingi 

 and cloa->- Av. Orchantky. 

 lug jaw. ) 



156 1 

 148 J 



On the hand. 



On the foot. 



With preparatory signal. 



Without *' '* 



184 Preparatory signal at regular intervals. 



121 Intensity of sound known. 



203 Intensity of sound unknown. 



163 Attention directed to sensation. 



laO ] " " movement. 



155 Normal. 



105 8 minutes after taking 60 com. of rum. 



characteristics of a simple re-action being in the attitude of 

 the re-actor, it would seem that its time could be little af- 

 fected by the nature of the impression. The motor signal- 

 ling process is the same, the connection between the im- 

 pression and movement is about equally artificial in all 

 cases, so that the chief variability must be in the time needed 

 for receiving the impression. For the different senses this 

 time is different. Taking the general average of all the 

 observations accessible to me, I find, for hearing, 1380'; 

 for touch, 148(5"; for sight, 185 (T. This order is quite con- 

 stant with the different observers, the long time of visual 

 re-actions being referable to the long inertia period of that 

 sense, as well as to the small perceptive area of the retina. 



in 135(7, of heat in 146(7, similar values for various points of 

 the hand being 121(7, 1880', 209ff. The researches of Gold- 

 seheider agree with these in the main, but make the differ- 

 ence between the re action times to heat and to cold much 

 greater. The senses of taste and smell clearly illustrate the 

 effect of the kind of stimulation, for here the relative inac- 

 cessibility of the sense organs and the slowly acting chemi- 

 cal processes involved lead to a long re-action time. Though 

 experimentation is difficult and uncertain in these senses, we 

 may cite for smell the results of Moldenhauer on the odors 

 of various oils, centring about 300(7 (oil of roses 273(7, cam- 

 phor 321<7, musk 319(7, ether 255(7, etc.), and for taste, of 

 Honigschmied, who re-acts to various tastes on the tip of the 



