Januaey 24, 1896.] 



SCIENCE. 



123 



ment, a healthjr young man, was kept with- 

 out sleep for ninety successive hours. Every 

 six hours elaborate physical and mental 

 tests were made upon him, and at the end 

 of the ninety hours the depth of his sleep 

 was tested every hour through the ten and ' 

 a half that he continued to sleep. 



During the ninety hours of waking, the 

 subject gained slightly in weight, though 

 his only additional food was a light lunch 

 taken just after midnight, but lost even 

 more during the period of sleep that fol- 

 lowed. The results of the tests may be 

 briefly summarized as follows : The loss of 

 sleep appeared to cause little loss of general 

 mental activity ; sharpness of vision, dis- 

 crimination of taste sensations and possibly 

 rapidity in reaction-times involving dis- 

 crimination increased. Simple reactions, 

 the pulse rate and the adding of figures 

 were somewhat slowed. Muscular power 

 was also somewhat lowered. In several of 

 these, however, the expectation of the end 

 of the test caused a return to near the nor- 

 mal during the last half day. Hallucina- 

 tions of vision , due probably to the unusu- 

 ally prolonged stimulation of the eyes, were 

 observed. The shortness of the period of 

 sleep required for entire recovery gives 

 ground for the belief that sleep is a relative 

 matter, and that, in spite of being kept as 

 fiilly awake as a man could be, the subject 

 nevertheless was more or less of the time in 

 a state of partial somnolence. 



The second paper was a brief repoi-t by 

 Prof. Mills, of McGill University, on Further 

 Researches on the Psychic Development of Young 

 Animals and its Physical Correlation. His 

 researches upon pure-bred dogs reported 

 last year have now been extended to mon- 

 grel dogs, the cat, rabbit, guinea pig and 

 birds, and their results will soon be pub- 

 lished. The mass of details involved pre- 

 vented more than an annoucement of the 

 work accomplished. 



Prof. Witmer's paper on Variations in the 



Patellar Reflex as an Aid to Mental Analysis 

 was next read. It contained an account of 

 a long and elaborate study of the knee- 

 jerk and its variations as a preliminary to 

 its use as an index of psychical activity in 

 studies of emotion. The varied details of 

 the paper forbid brief presentation ; certain 

 bilateral forms of experiment, however, 

 may be mentioned as of especial interest. 



The fourth paper was that of Prof. Hyslop, 

 of Columbia, entitled Experiments on Induced 

 Hallucinations. In it were reported with 

 critical comment a considerable set of ob- 

 servations by a lady of Prof. Hyslop's ac- 

 quaintance, on hallucinations secured by the 

 method of ' ci'ystal vision.' Few or none 

 could be traced by the observer to actual 

 experiences, but some may have had that 

 origin. Two or three would lend themselves 

 to a telepathic explanation, but are by no 

 means definite enough to have any confirm- 

 atory force in favor of such a theory. Per- 

 haps the greatest interest in such hallucina- 

 tions is the possible light which their ex- 

 amination may throw upon normal mental 

 action. 



The closing paper of the session was by 

 Prof. Newbold, of the University of Penn- 

 sylvania, on Dream, Reasoning. Three cases 

 were described, one where the subject-mat- 

 ter was mathematical, one in which it was 

 linguistic, and one in which it was archeo- 

 logical, the last two coming from the exper- 

 ience of a single person. In all three the 

 dream reasoning lead to results that were 

 valuable in waking life. 



At the regular business meeting held 

 after the discussion Saturday morning the 

 following officers were elected : President, 

 Prof. G. S. FuUerton, Univei'sity of Pennsyl- 

 vania; Secretary and Treasurer, Dr. Liv- 

 ingston Farrand, Columbia College ; Mem- 

 bers of Council, Profs. E. H. Griffin, Johns 

 Hopkins University, and E. C. Sanford, 

 Clark University. 



The following gentlemen were elected 



