328 THE POPULAR SCIENCE MONTHLY. 



cutting of his knife that is, that he unconsciously puts it in the right 

 position. 



Practice further exhibits its influence upon the nervous system on 

 its purely sensory side, abstracted from all movement. It sharpens 

 and corrects the musical ear, and teaches it to perceive over-tones, in- 

 exact intervals, and slight dissonances. The local sense and the color 

 sense of the eye are improved by practice. It teaches the wonderful 

 arts of quick reading, of taking in fleeting phenomena like the vibra- 

 tions of the magnetic needle, of bringing the sight of the gun to bear 

 on the black of the target. It teaches to distinguish copies and all 

 kinds of subjective appearances, to comprehend at a glance micro- 

 scopic pictures that pass before the beginner in superficial confusion, 

 in such a way that it is very hard to draw the line between exercise of 

 the sense and that exercise of the judgment over the impressions of 

 sense that is called visits eruditus. As exercise induces the discontinu- 

 ance of unused muscles, it also teaches us to neglect unused images, 

 such as the double images of the points of the picture outside of the 

 horopter ; or, in looking through an optical instrument, the impres- 

 sions made upon the unengaged eye. Yet no practice appears to break 

 through the law according to which the points of the retina in indi- 

 rect vision receive attention only transiently and with a certain effect. 

 Although it is hardened against bad smells, the nose of the chemist is 

 the rival of spectrum analysis in delicacy. It would be unjust to say 

 that the wine-connoisseurs of Bordeaux can discriminate concerning 

 the place of the growth of a vintage, while only its age is in question 

 with them. Not less susceptible of cultivation are the perceptions of 

 temperature, pressure, and locality. The last, especially, measured 

 according to the least distance at which two bodies, nearly in contact, 

 still separate, may be distinguished, become sharpened by practice in 

 the course of a few days giving one of the arguments which oppose 

 a purely anatomical definition of the range of feeling. 



As exercise refines the senses, neglect stupefies them, and that not 



merely in consequence of the apathy of the organ. After destroying 



the eyes and ears of new-born puppies, Herr Hermann Munk observed 



that what he had recognized as the visory and auditory spheres of the 



brain borders were backward in development. According to Hugue- 



nin, blindness of many years' duration results in waste of the visory 



spheres. 



< 



A CUEIOUS BURMESE TRIBE. 



By Lieutenant G. KEEITLEE, 



OF COUNT SZECIIENYl's CENTRAL ASIAN EXPEDITION. 



IN our journey from Sayang in Yunnan to Bhamo in Burmah, we 

 became acquainted with a race of mountaineers who are called 

 Kacheen by the Burmese, but who call themselves Chingpos. They 



