350 Report of the Committee on Colour-Vision. 



other by red ? — Yes ; I should describe such a case as not seeing 

 orange. 



Question — I understand Dr. Brown's test comes out under your 

 patronage ; may we therefore take it that you approve of that 

 method? — Not at all. A medical man might roughly test 

 with it. 



Question — Do you test by nomenclature or matching? — By 

 nomenclature, combined with matching. Many normal sighted 

 persons fail with Holmgren's test because they think a shade 

 is a colour, paying as much attention to the one as the other ; 

 if you say " I want you to pick out all the greens," you give them 

 something tangible to go upon. If a person in picking out 

 twenty or thirty greens also picked out half-a-dozen reds, it 

 would be certain he was colour-blind ; but if he has to match a 

 green wool he might pick out with the greens a light brown, and 

 not be colour-blind at all, and the error could be rectified by 

 explaining to him that the colour he selected was greenish- 

 brown, reddish-brown, or yellow-brown, as the case might be. 

 With Holmgren's test, under the same circumstances, he would 

 have failed. This might be confirmed by asking him to classify 

 the whole 150 colours. 



Question — Do I understand you that a normal sighted person 

 might pick out brown instead of pale green ? — Yes, because he 

 might pay more attention to shade than to colour. In testing 

 practically I should first use the Classification Test. I should 

 not begin with the spectrum with a practical test ; it would not 

 be convenient, and persons would object to it. 



[At this point the witness was asked to apply the Classification 

 Test to Mr. Rix. Mr. Rix was first requested, to pick out all the 

 shades of orange he could see, and in so doing he selected two 

 skeins of wool of a decided light green. Dark blue and violet 

 were matched as being of the same colour. In matching reds, 

 a reddish-brown was picked out, but described as having more 

 blue in it, and blue-green was sorted with the drabs, and referred 

 to as being brighter.] 



Witness. — The Classification Test is used in order that in- 

 experienced examiners might not have to depend upon the 

 Lantern Test — in which not more than twenty answers are 

 required. I do not use the Board of Trade colours with that 

 test, but my own. The person examined should be able to 

 distinguish between the red, green, and white lights, either 

 alone or modified with the neutral glasses. 



Question — Why do you think it necessary to have a preliminary 

 test to this ? — In order that an inexperienced examiner may feel 

 certain that the mistakes made with the Lantern Test are not 

 due to colour ignorance. 



Question — Have your investigations been with pathological or 

 congenital colour-blind cases ? — With both. 



The principles upon which I examine are as follows : — The 

 first principle which guided me in the selection of colours may be 



