5H POPULAR SCIENCE MONTHLY. 



perience corroborates what Professor Bryan* has said: that some 

 persons possess a leaky nervous system, wherefrom their vitalities 

 flow away without issue in useful results. In such individuals ac- 

 tivity will be likely to be in excess of that which the stimulus occa- 

 sioning it should normally produce. Every one must have seen 

 children, and adults as well, who when they hear a slight noise, for 

 instance, which others do not mind, react with great vigor by jump- 

 ing or screaming; or, when spoken to unexpectedly the face flushes, 

 the lip quivers, and they become physically uncontrolled in a meas- 

 ure. In these instances the persons are unduly profligate in the 

 expenditure of their means, and, in consequence, their capital is 

 relatively soon exhausted, f 



The writer last year conducted some experiments upon school 

 children which yielded results that appear to confirm the view here 

 set forth. Scripture's steadiness gauge was used in one test. This 

 is designed to investigate stability of control by requiring a person 

 to direct a light rod under guidance of the eye upon a point several 

 feet distant, failure to accomplish this being announced by the ring- 

 ing of an electric bell. The subject is usually required to make the 

 trial fifteen times at a single test, and the number of successful 

 attempts is taken to be in a way, although not always reliable, an 

 index to his power of co-ordination. But more important than the 

 success or failure in accomplishing the task is the index it affords of 

 the nervous condition of the subject as revealed in the expressions 

 of face and body. Tests were made in the morning, shortly follow- 

 ing the opening of school, and again at half past eleven o'clock, or 

 thereabouts, after the pupils had been working over their lessons 

 for about two hours. One boy of eleven years, A. M., is a fair illus- 

 tration of what might not inappropriately be called an exhaustive 

 type, wherein nervous energy is readily depleted because of inces- 

 sant waste. In the morning tests he was well controlled and accu- 

 rate. A record of five tests made at half past eleven all show that 

 after four or five attempts to place the rod upon the point the hand 

 became very unsteady, the lips compressed, the region about the 

 eyes showed unusual constraint, and the hand not being used was 

 tightly clinched. Ten trials were usually sufficient to produce 

 twitchings or tics in the face and body, although nothing of this was 

 ever noticed at other times. This boy invariably made hard work 

 of the task, and all the physical accompaniments indicated excess- 

 ive motor stimulation following, of course, upon an unduly ex- 

 cited condition of the cerebral cells. At the close of the experi- 

 ments he generally seemed exhausted, and upon three occasions 



* Addresses and Proceedings of the National Educational Association, 1897, p. 279. 

 f Cf. Warner, The Study of Children, chapters viii and ix. 



