Observations placeholder

As described in Illustrations Of The Influence Of The Mind Upon The Body In Health And Disease, Designed To Elucidate The Action Of The Imagination - Daniel Hack Tuke, M.D., M.R.C.P.,

PART III. THE WILL.
CHAPTER XIV. INFLUENCE OF THE WILL UPON SENSATION, THE VOLUNTARY AND INVOLUNTARY MUSCLES, AND THE ORGANIC FUNCTIONS.
SECTION III.— Influence of the Will upon the Involuntary-Muscles and the Organic Functions.

The exceptional influence of the Will over non-striated muscle, is exhibited in the power possessed by some persons of contracting or dilating the pupil at pleasure. Professor Laycock states that a gentleman now living (1860) possesses this power. He does not say whether the action of the Will was direct, or through the medium of ideas. Possibly he refers to Dr. Paxton, mentioned below.

The case of Prof. Beer, of Bonn, is thus described in the "British and Foreign Medico-Chirurgical Review," on the authority of Budge :

 "He is able in the same light to contract or dilate his pupil at will. This change in the size of the pupil, however, he brings about only through certain ideas ; when, for example, he thinks of a very dark space, the pupil dilates. When, on the contrary, he thinks of a very light place, the pupil contracts. He finds it more difficult to induce contraction than dilatation." It is added, "Budge has met with several other persons who can dilate the pupil in consequence of such ideas, but not another who can contract it also."

The reviewer holds that from such cases we must conclude, not that the motion of the iris is voluntary, but that the idea of a sensation can bring forth motions as well as the actual sensation itself. From the same source I take the following:

 "Professor Allen Thompson, of Glasgow, has lately published, in the ' Glasgow Medical Journal,' some remarks on the case of Dr. Paxton, of Kilmarnock, who possesses an unusual power of contracting and dilating the pupil, alleged to be voluntary and independent of any effort at adjustment of the eye. Dr. Paxton showed Dr. Thompson the motions of his iris, 'alternately contracting and dilating the pupil to a great extent, with apparent ease, at will;' and he informed Dr. Thompson 'that although, in producing the motions of contraction and dilatation of the pupil, he did not actually make an effort of adjustment, or attempt to fix the eye alternately on a near and distant object, yet the effort to make either of these motions seemed to him, as it were, very similar to the motions for adjustment.' …..
Dr. Paxton further stated to Dr. Thompson, in proof of his possessing a power greater than usual of moving the iris independently of adjustment, that he 'can fix the eyes upon a near object, and, while steadily looking at it, dilate the pupil without any effort for adjustment for distant vision, and while continuing to look at a distant object he can still further dilate the pupil and contract it at will, without any attempt at adjusting the eye for near vision.' In short, as Dr. Paxton himself informs us in a letter, ' he can alternately dilate and contract the pupil with as much facility as he can open and shut his hand,' and that, without the slightest effort at adjustment. This he can do also more rapidly than the pupil can adjust itself for near and distant vision. The pupil, Dr. Paxton says, has the ordinary action under the influence of light and shade, but he can always at will dilate it, whether the eyes be exposed to light or shade.
"It is by dilating that he must always begin the movements in question. By a slight effort of what appears to him to be relaxation, he dilates the pupil, and when the pupil is dilated, he can, by a slight effort of bracing up, contract it. Furthermore, Dr. Paxton says that it is not by raising up any idea in the mind, such as thinking of light and shade, that he calls forth the movements of his pupils, but by distinct efforts, and that he is always conscious, both by the state of vision and by the sensation in the eye, whether the pupil is in its normal condition or not"

(The British and Foreign Medical Review. Edited by Dr. Forbes ; and its successor, the British and Foreign Medico-Chirurgical Review, October, 1857).