702 COLOR-VISION AND COLOR-BLINDNESS. 



reject both; but this is a difference depending sometimes upon imper- 

 fect color education, sometimes upon the interpretation i^laced upon 

 the directions of the examiner, but the person who so selects sees the 

 green element in the yellow greens and in the blue greens, and is not 

 color-blind. The completely color-blind, whether to red or to green, 

 will proceed with almost as much speed and confidence as the color 

 sighted; and will rapidly pick out a number of drabs, fawns, stone 

 colors, pinks, or yellows. Between the foregoing classes we meet with 

 a few people who declare the imperfection of their color sense by the 

 extreme care with which they select, by their slowness, by their hesi- 

 tation, and by their desire to compare this or that skein with the pat- 

 tern more narrowly than the conditions of the trial permit. They may 

 or may not ultimately add one or two more of the confusion colors to 

 the green, but they have a manifest tendency to do so, and a general 

 uncertainty in their choice. One of the great advantages of Holmgren's 

 method over every other is the way in which the examiner is able to 

 judge, not only by the final choice of matches, but also by the manner 

 in which the choice is made, by the action of the hands, and by the ges- 

 tures and general deportment of the examinee. 



When confusion colors have been selected, or when an unnatural 

 slowness and hesitation have been shown in selecting, the examinee 

 must be regarded as either completely or incompletely color-blind. In 

 order to determine which, and also to which color he is defective, he is 

 subjected to the second test. For this, the wool is mixed again, and the 

 pattern this time is a skein of light purj^le — that is, of a mixture of red 

 and violet, much diluted with white. To match this, the color-blind 

 always selects deeper colors. If he puts only deeper purples, he is in- 

 completely color-blind. If he takes blue or violet, either with or with- 

 out purple, he is completely red blind. If he takes green or gray, or 

 one alone, with or without purple, he is completely green blind. If 

 he takes red or orange, with or without purple, he is violet blind. If 

 there be any doubt, the examinee may be subjected to a third test, which 

 is not necessary for the satisfaction of an expert, but which sometimes 

 strengthens the proof in the eyes of a bystander. The pattern for this 

 third test is a skein of bright red, to be used in the same way as the 

 green and the purple. The red blind selects for this dark greens and 

 browns, which are much darker than the pattern; while the green blind 

 selects greens and browns which are lighter than the pattern. 



The method of examination thus described is, I believe, absolutely 

 trust- worthy. It requires no apparatus beyond the bundle of skeins of 

 wool, no arrangements beyond a room with a good window, and a table 

 with a white cloth. In examining large numbers of men, they maybe ad- 

 mitted into the room fifty or so at a time, may all receive their instructions 

 together, and may then make their selections one by one, all not yet 

 examined watching the actions of those who come up in their turn, and 

 thus learning how to proceed. The time recjuired for large numbers 



