190 COLOR-BLINDNESS IN ITS RELATION TO 



It results from all this that many who are finally considered to have 

 a normal chromatic sense may occasionally cause embarrassments. In 

 the main, the normal observer of this kind causes greater loss of time 

 than the color-blind. It is astonishing to see with what rapidity the 

 color-blind betray their defect. At least, it is found, in the majority of 

 the cases examined by us, that the first skein of wool selected from the 

 13ile by the color-blind in the first test was one of the "colors of con- 

 fusion." 



B. Intervention during a restricted clioice. — Those who evince too great 

 slowness also require the interferences of the examiner in another man- 

 ner. We can lay aside here those cases in which at the sight of the 

 complex colors of the heap of wool, the examined finds it difficult to 

 select a skein resembling the sample in a collection where all the particu- 

 lar colors seem to differ from each other, and in consequence declares im- 

 mediately that he can find none resembling the specimen. It is replied 

 that an absolute resemblance is not demanded, and that no one asks 

 impossibilities, that time is limited, many are waiting, etc. But there 

 are people who from natural slowness, from being unaccustomed to such 

 business, from fear of making mistakes, and especially if jireviously ex- 

 amined and suspected of color-blindness, or from many other motives, 

 proceed with the greatest caution ; they do not even wish to touch the 

 wool, or they search, select, and replace with the greatest care all the 

 possible skeins without finding one corresponding with the sample, or 

 that they wish to place beside it. Here then are two cases: on one hand, 

 too much action with the fingers, without result; on the other, too little 

 effort. The examiner is forced to interfere in both cases. 



[a) At the time of a too great manual action without corresponding 

 practical result, the examiner must be careful that the eye and hand act 

 simultaneously for the accomplishment of the desired end. 



Some people forget that the hands should be subservient to the eye 

 in this trial, and not act independently. Thus they are often seen to fix 

 their eyes on one side while their hands are engaged on the other. 

 This should be corrected so as to save time and avoid further labor. 

 When, from the manual activity of the one examined, or by the unob- 

 served aid of the examiner, all the correct skeins or only a portion are 

 found in the pile, it is wise to stop and invite the former to cross his 

 hands behind his back, to step back a pace, and quietly consider all the 

 skeins, and, as soon as his eye has met one of those for which he is look- 

 ing, to extend his hand and take it. The best plan is to advise him to 

 look first at the sample and then at the pile, and to repeat this maneuver 

 until his eyes find what he is looking for. 



This stratagem generally succeeds when nervousness from over-anxiety 

 causes his hands to tremble. But it is not always easy to induce him 

 to keep his hands behind his back until the moment for taking the skein 

 in question. 



(ft) In cases of great caution, the trial is hastened, if the examiner 



