January 24, 1919] 



SCIENCE 



97 



meiit was authorized by the Officer in Charge 

 of the Laboratory, and later by the board, to 

 conduct experiments and secure data bearing 

 on the question * * » . The specific point 

 on which we commenced work was whether 

 the duration of nystagmus after rotation is an 

 index of the sensitiveness of the mechanisms 

 for appreciating motion and maintaining 

 equilibrium. Other questions raised outside 

 of the laboratory, e. g., as to how far the 

 semicircular canals constituted the mechanism 

 involved, or whether they were the sole mech- 

 anism, seeming to us to have no practical 

 bearing on the issue. 



Our first attack on the problem consisted in 

 observations on circus performers, vaudeville 

 stimters, and dancers, in the effort to deter- 

 mine the nystagmus-reactions of these indi- 

 viduals of demonstrated high ability in equili- 

 bration. These observations were started by 

 Captain G. R. TVells, and after being dis- 

 continued because of the necessity of sending 

 him to a field station, were taken up by Cap- 

 tain Bentley. The results of these observa- 

 tions indicated the necessity of attacking the 

 problem of practise-effects by controlled ex- 

 periments. I consulted a well-known dancing 

 teacher in New York City, who advised a 

 daily practise period of half an hour, proph- 

 esying striking results in two weeks. 



The experiment was carried out by Captain 

 Bentley, on five men, who showed " normal " 

 nystagmus the first day, when tested by Cap- 

 tain Wales, who had had exiierience in con- 

 ducting the nystagmus test on examining 

 boards. This observation was checked by 

 Captain Bentley by more exact methods. 

 Each man was given turning at the " stand- 

 ard " rate — ten turns in twenty seconds — first 

 in one direction, then after a brief resting 

 period in the opposite direction, and so on, 

 for approximatel.v half an hour. The total 

 time of turning during the half hour was be- 

 tween three and four minutes. At the end 

 of each set of ten turns, the nystagmus dur- 

 ation was recorded by an admirable method 

 devised by Bentley. Practise was given as 

 near daily as possible, but was interrupted by 

 Sundays and military duties. 



The nystagmus duration showed a reduc- 

 tion from day to day, following the form of 

 the usual practise curves derived from other 

 experiments on learning and habituation. In 

 a short time all the men had durations far 

 below the official lower limits for passing 

 candidates (16 seconds) and one showed no 

 nystagmus at all. The equilibration of these 

 men was certainly no iworer than when they 

 showed the " normal " nystagmus at the be- 

 ginning. 



An interesting field for further work on 

 nystagmus was opened up by these investi- 

 gations, which however had gone far enough 

 to settle the point of practical military im- 

 portance. It would have been well to ascer- 

 tain the effect of varying the rate of rotation, 

 * * * , and as I and the other men concerned 

 in the experiments were shortly transferred 

 from duty with the Medical Research Board, 

 the investigation lapsed at that point. 



The tests * * * which were carried on in 

 airplanes upon deaf subjects and others, we 

 had nothing to do with. * * * 



Knight Dunlap 



The Johns Hopkins Univeesitt 



THE MATHEMATICAL ASSOCIATION 

 OF AMERICA 



The third annual meeting of the association was 

 held at the University of Chicago on Friday, De- 

 cember 27, 1918, in conjunction with the annual 

 meeting of the American Mathematical Society. 

 Eighty-six were in attendance at the sessions. 



The first session was devoted to the subject: 

 "Deductions from war-time experiences with re- ' 

 spect to the teaching of mathematics. ' ' This was 

 a conference participated in by representatives of 

 colleges and universities in which the Students ' 

 Army Training Corps were located, including R. 

 P. Baker, University of Iowa; W. D. Cairns, Ober- 

 lin College; A. E. Crathorne, University of Illi- 

 nois; D. R. Curtiss, Northwestern University; W. 

 B. Ford, University of Michigan; A. M. Kenyon, 

 Purdue University, and H. E. Slaught, University 

 of Chicago. These men reported upon the meth- 

 ods used and the probable lessons to be gained for 

 the future of collegiate mathematics. Professor 

 D. R. Curtiss also gave an account of "An experi- 

 ment in supervised study" this being followed by 



