374 SECTIONAL TRANSACTIONS.— J. 



group of sensory-motor tests has been called ' aesthetokinetic tests,' because they 

 intercorrelate among themselves in a small degree and also have the common factor 

 of requiring a visual, auditory or tactual stimulus to be reacted to by a movement 

 requiring rapid and accurate co-ordination. 



Certain tests connected with temperamental instability have also shown a relation- 

 ship to accident incidence, but on account of certain difficulties in scoring they were 

 not included in the final weighted score. Their use will probably be greatest in 

 deciding cases left doubtful by the other tests. 



No relation has up to the present been established between intelligence and accident- 

 rate, but the data on which this conclusion is founded are not so extensive as that 

 yielded by the aesthetokinetic tests, and further research is being carried out to 

 elucidate this particular aspect of the problem. 



The conclusions arrived at by the Industrial Fatigue Research Board are admittedly 

 preliminary, and much further work needs to be done before results obtained by this 

 method can be regarded as of practical value. Sufficient, however, has been done 

 to show that inequality in accident rate is a personal measurable quality, and future 

 research must be directed towards determining to what extent it can be measured 

 and by what tests the best measures can be obtained. The Industrial Fatigue 

 Research Board is at present engaged in an extensive research along these lines, but 

 several years must elapse before the results can be properly appraised. 



Friday, September 2. 



Mr. R. J. Bartlett. — Feeling and the Psychogalvanic Reflex. 



The ' emotion ' theory of the ' reflex ' has been challenged by a ' conation ' theory. 

 The experimental basis of neither theory is fully conclusive. Attempts have been 

 made to secure under experimental conditions mental states in which, unequivocally, 

 ' feeling ' should be the dominant factor in experience. Expariments will be described 

 and results submitted to demonstrate that the ' reflex ' follows a variety of complex 

 mental states, some at least of which include a phass that would ordinarily be described 

 as ' feeling,' and that differences in the form of tachogram record provide an objective 

 basis for classification of these complex experiences. 



Dr. R. H. Thouless. — -FecJmer's Law. 



Fechner's law is a valid mathod of measuring sensation over the range for which 

 Weber's law is true. His central step of treating just noticeable differences of 

 sensation as equal is, however, to be regarded as a convention of measurement. 



Dr. D. N. Buchanan. — The Psychological Effects of Flickering Light. 



Dr. F. W. Edridge-Green, C.B.E. — The Classification of the Colour-blind. 



There are probably no subjects in science in which there are more misstatements 

 than in vision and colour vision. A classification of the colour-blind should, therefore, 

 be made only on facts ; this classification can easily be made with the aid of my 

 spectrometer, with which any portion of the spectrum can be isolated. 



Cases of colour-blindness may be divided into four distinct classes, each of which 

 may occur separately or they may be combined. These classes are (1) Defective hue 

 discrimination, (2) Defective light perception, (3) Defective perception of colour 

 through the foreal or central region of the retina not being normal, or supplied 

 normally, (4) In this class, while there is no defect in colour discrimination or defective 

 light perception, one or more colours do not occupy the normal position. For 

 instance, the position of pure yellow instead of being at . . 585, as in the normal sighted, 

 is in the yellow -green or orange-yellow. These cases can hardly be called colour- 

 blind, but are really colour different, but have to be taken into consideration in 

 testing colour-blindness for a practical object. 



Defective hue discrimination may be classified according to the number of colours 

 which are seen in the spectrum, check examinations being made to prove that the 

 examinee sees as described by him. One man will declare that there is no difference 

 in colour over the whole spectrum but simply variations in brightness ; another will 



