3084
THE NEW ZEALAND GAZETTE.
[No. 74

all of the skeins belonging to that colour, or else several incorrect skeins. If he is colour-blind he will most probably select greenish-yellows, light yellow-greens, fawns, and pinks.

Remark.—Every case of comparatively complete colour-blindness does not always give precisely the same mistakes. Instances occur of persons who are not completely colour-blind, or of completely colour-blind persons who have been practised in the colours of signals, and who endeavour not to be discovered. They usually confound at least green and brown, but even this does not always happen.

Monochromatic Vision.—The absence of every colour sensation except one will be recognised by the confusion of all the hues, which will appear to be of the same intensity of light or brightness.

Special Instructions to Examiners.

In the conduct of the colour-test the sole question under consideration is whether or not the candidate has normal colour-vision, and, in order to answer this question satisfactorily, no pains must be spared by the Examiner to make the candidate fully understand what he is expected to do. As the result of the local examination often hinges upon the adequacy or otherwise of the instruction given to the candidate, together with the intelligent interpretation of the rules laid down for the guidance of the Examiner, it is very important that Examiners should be able to modify their mode of procedure with different candidates in order to gain the best results from the varied types which come up for examination in these tests.

Before going into the question of how to treat different cases, Examiners should always bear in mind that no amount of verbal explanation is equivalent to practical instruction, and as the test is in no wise vitiated by being seen beforehand, opportunity should be given, when possible, to prospective candidates to see others tested. Candidates undergoing the colour-test may be broadly divided into two classes, irrespective of whether they are colour normal or not—viz., (a) those who make a rapid selection of a large number of skeins to the required test, and (b) those who are slow and hesitating. In the majority of cases the simple request by the Examiner for the candidate to “pick out from the heap of wools all those skeins which are of the same colour—both lighter and darker—as the test-skein” will be found sufficient, but where a candidate shows a tendency to pick out a large number of skeins which even remotely resemble the test-skein in colour as in (a) he should at once be stopped, and be given to understand that it is not desired that the original test-colour should be graded off into another—i.e., by his introduction of, say, yellow-green skeins into the first test he can easily be shown that a simple graduation of shade will speedily land him in yellow, or a very near approach to it. This can best be demonstrated by the Examiner taking one of the shades of yellow-green verging on yellow and placing it beside the test-skein, at the same time asking the candidate if it is the same colour, when, if the candidate is colour normal he will very likely at once remark that it is too yellow. The candidate should then be told to return the whole of his selections to the heap, and, after reshuffling them, be made to commence afresh, when in all probability he will understand what is required and the test will be rapidly completed. The same remarks apply to cases where the blue-green range of skeins is introduced.

It will be seen that the introduction of these mixed green skeins need not be taken as a positive indication of defective colour-vision, as the chances are that these selections are made through ignorance of what is required. Should, however, the candidate introduce amongst the selections any obviously incorrect skeins—i.e., skeins in which there is no green—the Examiner must proceed carefully, noting at the same time any tendency to handle incorrect skeins and to compare them with the test-skein. In cases of this kind, when there are other candidates up for examination, it is best to postpone the trial until the candidate has had an opportunity of seeing what is done by others, or, failing this, the Examiner himself should pick out all the correct skeins to the test, showing the candidate what he is expected to do. If the candidate has defective colour-vision the same characteristic mistakes will be made. The second case (b)—where a candidate is slow and hesitating—may be due to several causes—nervousness, anxiety as to result, real or fancied defective colour-vision, &c. All candidates, the latter especially, must be tactfully dealt with, in order to get the best results from the examination. Candidates of this latter type often evince a tendency to obstruct their work by gathering up handfuls of the skeins with one or both hands and turning them over without any result, at the same time bending over the wools in a more or less strained position. The Examiner should then quietly tell the candidate to stand back a moment, and, having spread out the skeins again, tell him to put his hands by his side, look at the heap of wools, and when he thinks he sees a skein of the required colour to pick it up and place it beside the test-skein, at the same time showing him practically what he means him to do. This will tend to reassure him, and at the same time give him a chance of seeing the skeins required, and the test should be continued until all or nearly all the correct skeins have been picked out. Again, candidates will be found who show a tendency to compare skeins with the test-skein, and if not exactly the same shade (though perhaps quite correct in colour) to reject them. This is very likely due to failure to understand the instructions given by the Examiner, and the candidate should then be reminded that he will find no exact match, but that several shades of the same colour, both lighter and darker, are to be found in the heap. Should he, however, evince a tendency to compare obviously incorrect skeins with the test-skein, careful note should be taken of the colours. Candidates of this type, whose colour-vision is defective, and who may be aware of the defect, will probably select few wools on the chance that what they pick out may be correct. It is accordingly essential that in all cases a fair number of skeins to each test should be required, as the colour-blind candidate may, of course, pick out correct skeins as well as incorrect ones, since all look more or less alike to him. The experienced Examiner can usually recognise such cases by the tentative manner in which the various skeins are handled; and, although the candidate may not actually compare incorrect skeins with the test-skein, the fact that he has seriously handled them with a view to selection should be carefully noted. When the candidate has successfully passed the first test, as a rule, the other tests will be passed easily; but the same care must be taken to see that the test-colour, and that only, is selected, or if incorrect colours are seriously handled or compared with the test-skein, a careful note must be taken as before.

In no case should an Examiner pick up incorrectly selected skeins and ask the candidate, “Do they match the test?” If the Examiner is not satisfied that the candidate knows what he is expected to do, the whole of the wools should be returned to the heap, and the test commenced anew, when, if the candidate is really defective in colour-sense, the same characteristic mistakes will be made.

Examiners should bear in mind that these tests should always be conducted in a good light. The skeins of wool should be placed on a table covered with a white cloth or paper of sufficient size, so that ample room is