Literary Notices. Ixxiil 



ble molecule became differentiated <,o such an extent that it reacted 

 differently to red, green and blue rays, although when all these vibra- 

 tions are present the substance is transformed, producing a sensation 

 of grey (i. e. the white-black series). The state of total color-blind- 

 ness is considered a case of atavism. 



When red light, for example, has been acting upon the retina for 

 some time many of the photo-chemical molecules have lost that one of 

 their constituents which is the exciter of the red sensation; but in this 

 mutilated condition they are extremely unstable and their other two 

 constituents (exciters of green and red) are gradually set free. 



Experimental Investigation of tlie Relation between Respiration and 

 Attention.^ 



Miinsterberg has proposed the theory that the muscles of sensory 

 accommodation are involuntarily innervated simultaneously with the 

 muscles of respiration in cases of momentary registration. This the- 

 ory was rendered necessary to explain the variations of attention de- 

 tected by N. Lange. 



The author instituted a series of experiments where the respira- 

 tory curve was registered upon the same kymograph cylinder as the 

 registration of the observer. He concluded that the periodic incre- 

 ment of sensation during constant irritation appeared as frequently 

 during expiration as inspiration, but occurs rarely in the respiratory 

 pause or maxima. He explained this fact on the assumption that 

 there is slightly less blood pressure in the brain during the pause and 

 a relatively greater expenditure of energy in other directions at the 

 maxima and both these conditions interfere with the normal develop- 

 ment of the sensation. Thus the so-called variation in attention is 

 explained, through fatigue of accommodation apparatus may also enter. 



Muscular Sense of tlie Blind. 



Dr. Goldschneider claims that the blind exhibit a higher develop- 

 ment of the sensations of passive motion in the hand and finger 

 joints, the cause being psychical and consisting in an increased 

 power of attention. The sense of position is not noticeably im- 

 proved. In the recognition of form by tactile methods the sensations 

 of motion are more important than tlie sensations of the skin. Chil- 

 dren have a more delicate sense of passive movements than adults. 



^ Lehmann, H. Experimentelle Untersuchung liber die Beziehung zwischen 

 Respiration und Aufmerksamkeit. Internat. Congress Exp. Psych., i8g2. 



