[Andrej]

124-128

the blind so that the strip may be fully illuminated. Directly he considers his eyes to be sufficiently colour-blinded, he turns towards the patient and looks at some predetermined point on the median line of the body, when (if used transversely) the complementary coloured band will be seen reaching right across the body and partly extending to the background on either side, all being simultaneously visible. This allows him to notice variations in the shades of colour in every part of the band. Of course, the tints of the parts of the band extended beyond the body can be compared with each other, but, not with the portion on the body itself. The above method seems a very simple process, but it will require a considerable amount of practice, and the mastery of one or two details, trifling in themselves, will assist greatly in the speed and comfort of the experiment.

First, while looking at the coloured slip, it is requisite not only to fix the eyes on one particular spot, but to keep this in exact focus the whole time, as there is a great tendency to blurring which will greatly increase the length of time necessary for gazing at it. A slight effort of the will is needful for this, but in a short time habit will make the strain almost involuntary. If this spot on the coloured slip be replaced by a letter or figure, a double purpose will be served, a fixed point and a means of registration will both be gained. Secondly, a difficulty is experienced when beginning this inspection, in keeping the eyes fixed upon a given spot on the patient's body, owing to the proneness of the complementary coloured band to move, often out of the line of vision and the eyes follow it, thus completely destroying the benefit of the observation. As soon as the habit of keeping the eyes stationary upon one point has been acquired, the complementary coloured band will remain fairly motionless, and should it move away it will return again to the proper position of its own accord. As dexterity is only acquired by practice, it is a good plan to train the eyes upon some inanimate object before proceeding to the examination of a human subject.

In the following description, unless otherwise specified, the yellow strip with its blue complementary coloured band will be the colour implied. For brevity's sake the term C. C. will be employed for complementary coloured, and P. C. will mean the primary colour or the colour of the strip gazed at. As, naturally, there are slight variations of the skin and shadows on the body of the patient, the observer ought to notice every modification however insignificant, before commencing inspection with the C. C. band. With care, judgment and a little experience most of the difficulties arising from these causes will disappear. In its simplest aspect the C. C. band projected on a body in good health, will be equal in tint all over, after due allowance has been made for any deviation of the colour of the skin. The extensions of this band on the two sides often, but not always, correspond in hue. These extensions, as would be expected, have invariably quite a different tint from that of the part of the C. C. band lying on the body itself, mainly on account of the colour of the background.

When the extensions of the C. C. band of a healthy subject show a tint on the one side unlike that of the other, the difference is rarely great. This diversity of shade is the simplest form of alteration of the C. C. band, and unless sufficient care has been taken, may be due to imperfect lighting; however, any doubt can be dissipated by turning the patient round, when, if correct, the different tints will have changed places, being a proof positive that the alteration is an effect of the Aura itself. Another very characteristic method when successful, is to notice which extension of the blue C. C. band has the deeper colour, and then to gaze at the blue P. C. strip which gives a yellow C. C. band. Frequently, but not always, the latter will have a lighter shade where the blue C. C. band was darker, and vice versa. One of the chief variations of the C. C. band, when projected transversely upon the body of a patient not in good health as he stands facing the observer is, that one side will be darker than the other. When this happens, the two shades of colour may blend gradually into each other, or a sharp line of demarcation may divide them. In the latter case the division most frequently takes place in the median line of the body, but exceptions are numerous and the line of separation may occur any distance to the right or left. If the C. C. band (on one side light and on the other dark) be continued beyond the body, the extension on the light side will have invariably a lighter shade than the extension of the dark portion of the band. The dark part generally overlies some deranged portion of the body, and it will be found that this part has absolutely become darker than the rest of the band. However, the deranged part of the body may cause the C. C. band to become lighter instead of darker.

But slightly different is another variation, in which instead of the C. C. band across half the body being changed in shade, only a patch, large or small, is noticed to be dark or light and wholly surrounded by the natural colour of the band. When the patch is large it occasionally takes the outline of an organ in whole or in part; the small patches not exceeding about an inch in diameter, do not of themselves disclose what organ is affected, although they generally point to some disease or local disturbance and almost invariably to the seat of tenderness or pain. In these instances when the colour change is slight,