SECTIONAL TRANSACTIONS.—I, J. 447 
15. Dr. F. W. Eprivar-Green, C.B.E.—The Change of Hue caused 
by the Addition of White Light to Spectral Colours. 
The apparatus used in these experiments was that described in the Proceed- 
ings of the Royal Society, B, Vol. 92, page 232 (1921). 
Various spectral colours were isolated on a screen coated with magnesium 
oxide and definite proportions of white light, taken from the source, which was 
a 1,000-candle power Tantalum Arc, added. The scale of white light is arbi- 
trary; the maximum amount of light it is possible to add being 100 divisions. 
A comparison white light taken from the source was used. Each colour 
became less saturated on adding white light. Red first became orange, then 
yellow. Orange became yellower, A 585 pu., pure yellow did not change in 
hue. Orange-yellow and yellow-green became yellow. Green became yellow- 
ereen. Blue A 480 py. became white, the comparison white appearing yellow. 
The violet end of spectrum from A 480 jp., making a blue on the screen, 
changed to violet on adding 33 divisions of white light, light purple on adding 
100 divisions. 
Wave-length 585, the point where the addition of white light produces no 
change of hue, is also the centre point of pure yellow and the apex of the 
luminosity curve. 
The result of these experiments shows that the component part of white 
light which has the greatest luminosity effect is the hue to which all colours tend 
on the addition of white light. 
16. Dr. J. H. Suaxsy.—The Testing of Colour Discrimination. 
SECTION J.—PSYCHOLOGY. 
(For references to the publication elsewhere of communications entered in 
the following list of transactions, see p. 466.) 
Thursday, September 8. 
1. Joint Meeting with Sections F and L. Discussion on Vocational 
Training and Tests. See p. 455. 
2. Dr. H. S. Lanareiy.—The Study of Personality. 
Laboratory experiments, whether positive or negative in the principal results, 
usually yield individual differences, which in themselves may have considerable 
value both for the solution of theoretical problems and for applied psychology. 
An attempt is being made at present to correlate the individual differences 
which occur in the various researches of the psychological laboratory with the 
results of vocational and so-called intelligence tests. It is hoped in this way 
to discover the fundamental characteristics which constitute personality and to 
devise methods of accurately measuring such characteristics. The results so 
far obtained give promise of securing a ‘profile’ of the intellectual and 
emotional life of the individual. The problem involves a general consideration 
of experimental methods. 
3. Miss M. McFarnane.—Sex Differences in Tests of Constructive 
Ability. 
An investigation into the nature of ‘Practical Ability ’ showed that in the 
construction test used, viz., fitting together a sectional wheelbarrow, boys 
scored much better than girls. 
A further series of tests was planned to determine whether this superiority 
can be accounted for by : 
(a) The relation of the object to be made to existing interests. 
(6) Familiarity with this particular type of material. 
