Report of the Committee on Colour-Vision. 323 



The Chairman: What authority has the Liverpool Board of 

 Trade ? Is it simply limited to Liverpool ? 



The Witness : Yes, the powers of the Central Board of Trade 

 are given over to the Liverpool Board for Liverpool. 



Question. — Will you give us your practical experience with 

 regard to different methods of testing ? 



The Witness : I have very little hesitation in saying that all tests 

 requiring a man to name colours are defective. Practically, that 

 brings them down to Holmgren's, which is the simplest, and, for 

 ignorant men, the best one. I consider that test perfectly trust- 

 worthy, and it has one great advantage — it can be applied 

 irrespective of nationality. 



The Chairman : As a matter of practical experience, about 

 what time do you find it takes in using Holmgren's test ? 



The Witness: I calculate about 40 boys an hour, or 100 

 girls in the same time. The time taken depends a great deal 

 upon the social standing of the children. At Eton or Harrow it 

 would be very different to that at reformatory schools, where 

 perhaps only thirty boys could be examined in an hour, as they 

 are so ignorant that a test has to be explained to them over and 

 over again in order that ignorance may not be mistaken for 

 colour-blindness. I am acquainted with Professor Grossman's 

 test, and 1 think it a test for experimental purposes, but not for 

 practical use. Captain Smith, of whom I have already spoken, 

 passed it without difficulty. He was examined by the Board of 

 Trade card test and lanterns. He was then asked by Sir George 

 Powell to see Dr. Grossman, and Captain Smith told me he named 

 the letters rightly. I tested him on two or three occasions with 

 Dr. Grossman's test, and he never made a mistake. 



Question. —Did Dr. Grossman supply the test you used ? 



The Witness : I got it from the optician from whom he said it 

 might be obtained. In many cases it would be difficult to reject 

 with this test, all hough feeling sure the candidate was defective. 

 An educated colour-blind man would get through. There is also 

 the disadvantage that it takes considerable time to apply. 



The Chairman : What was the nature of Captain Smith's 

 colour-blindness ? 



The Witness : I do not for the moment remember. I do not 

 find the great distinction which is laid down between the different 

 kinds of colour-blindness. The one class appears to run into the 

 other. 



I think different classes do exist, and in great number. 



I have not examined cases with regard to the shortening or 

 non-shortening of the spectrum. 



The Chairman : You have no suggestion to make with regard 

 to tests ? 



The Witness : None, except that I pin my faith to Holmgren's 

 test applied by an expert examiner, and carried out according to 

 Holmgren's instructions. 



