Report of the Committee on Colour -Vision. 359 



" Under the circumstances the Commissioners regret that they 

 are not in a position to assist your Committee. 



" I have the honour to be, Sir, 



" Your obedient Servant, 



"J. E. LOCKHART. 



" Capt. Abney, R.E." 



"M. 4624. "India Office, 



" Whitehall, S.W., 



" 29th May, 1890. 



" Sir, — I am directed by the Secretary of State for India in 

 Council to acknowledge the receipt of your letter of 20th May, 

 and to acquaint you in reply that the tests for Colour Blindness 

 used by the Medical Board at this Office, in the examination of 

 candidates for the Indian Service, are Holmgren's coloured wools. 

 First a pale grass-green skein of wool is selected, and the 

 candidate is requested to pick out from the heap of coloured 

 wools others of the same type of colour, irrespective of shade ; 

 if he readily selects the greens he is considered to be free from 

 Colour Blindness, though the further tests are usually applied ; 

 if he picks out any of the confusion coloured greens, drabs, pinks, 

 yellows, &c, he is Colour Blind. 



" The second test used is a light purple or rose colour ; if he 

 matches this with blues or violets he is pronounced red blind, if 

 with greens or greys he is pronounced green blind ; if he passes 

 the second but fails in the first test his colour sense is weak. 



" The third and confirmatory test is a bright red ; if he is red 

 blind he chooses dark greens and dark browns ; if green blind, 

 bright greens and bright browns. 



" I am, Sir, 

 " Your obedient Servant, 



" 0. N. Newmarch, 

 "Maj.-Gen., 



" Military Secretary. 



" Capt. W. Abney, RE., 



" Science and Art Department, 

 " South Kensington." 



" Admiralty, 



" 21th May, 1890. 



"My Lord, — With reference to letter of the 16th inst., request- 

 ing, on behalf of a Committee appointed by the Royal Society to 

 enquire into the subject of Colour Vision, information as to the 

 methods employed by the Admiralty for testing Colour blindness, 

 I am commanded by my Lords Commissioners of the Admiralty 

 to acquaint you that candidates who are examined for entry into 



VOL. LI. 2 B 



