Experiments on the production of an imitation of sea sickness by complex visual disturbances / by Graily Hewitt.

  • Hewitt, Graily, 1828-1893.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Experiments on the production of an imitation of sea sickness by complex visual disturbances / by Graily Hewitt. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Reprinted for the Author from the British Medical Journal, May 21, 1892. EXPERIMENTS ON THE PRODUCTION OF AN HMITATION OF SEA SICKNESS BY COMPLEX VISUAL DISTURBANCES. By GRAILY HEWITT, M.D., F.R.C.P., Emeritus Professor of Obstetric Medicine, University College; Consulting Obstetric Physician to the Hospital. The subject of sea sickness has at various times occupied my attention. Personal experience of the Channel passage on many occasions has furnished me with facts bearing on the question as to the cause of sea sickness ; and some time ago these facts had led me to the conclusion that in my own individual case the attack of sea sickness—otherwise inevit- able in rough weather—could be prevented in two ways : (1) by fixing the eyes on some object away from the vessel, or (2) by completely and continuously closing the eyes and thus for the time abolishing the exercise of the sense of vision. While staying at a house in the country I was one day using a large glass wardrobe-door mirror. While brushing the hair sensations were perceived like those of on-coming sea sickness. The cause was not immediately apparent, but I soon observed that the wardrobe door, which was delicately hung, was slightly moving all the time, and the movement of the mirror was evidently the cause of the incipient qualmy sensation I had experienced. This observation induced me to make experiments by the aid of a mirror in order to deter- mine more precisely the effect of visual impression disturb- ances in the production of sea sickness. I first employed a large mirror, 6 feet by 4f feet, suspended in a frame so that the mirror could be easily moved in any required direction, the observer seated in a chair 5 feet, from the mirror. It was found that in some of the cases experi- mented on a feeling of giddiness ensued when the mirror, being hung at its centre, was oscillated from side to side for a quarter of aji hour. The same effect resulted from fixing the mirror at the two sides, leaving it free to be oscillated at the top and bottom of the mirror. Shortly afterwards a more effective oscillation was found to be produced by suspending the mirror by cords fixed at two opposite oblique corners of the mirror, so that the mirror could be oscillated on its oblique axis. Giddiness was the principal effect produced by the oscillations in the cases tried. It is to be noted that the carpenter who erected the frame for suspending the