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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    varying at different moments in nature and degree. His position under these circumstances resembles that of an indi- vidual placed in the swing of the apparatus before described; his body has imparted to it an oblique motion which is neces- sarily productive of obliquity of visual disturbance. There is produced then a double obliquity by the action of the ship, which can be closely imitated by the moving mirror and swing. It should be pointed out further that at sea, as well as in the swing, the individual has the power of to a certain degree lessening the intensity of the visual disturbances to which he is subjected by moving the head or body in such a manner as to correct some of the disturbance. Thus, if he moves the trunk a little to the left when the deck of the vessel is sinking away to the right, an upright position of the body is preserved; and so again, when the vessel pitches, if he moves the head and trunk a little backwards, this preserves a vertical position, and destroys to a certain extent what may be conveniently described as the “platform ” disturbance. The foregoing observations and remarks were recorded but not published nearly seven years ago. I had intended to make further experimental observations before publishing them, but circumstances have hitherto interfered with the carrying out of this intention. In my earlier personal experiences of sea sickness I learned that, when the objects looked at are away from the vessel and therefore comparatively fixed—for example, the clouds, the horizon, the sea shore (if in view), or a passing vessel—when some such object could be fixedly regarded, no part of the vessel in which the voyage is made intervening, the sensa- tion of sea sickness could be kept off even in rough weather. For moderately susceptible cases this method of preventing siokness answers extremely well; but it necessitates being on deck and so placed as to be able to look easily away from the ship. The benefit of this fixation of the eyes on some object away from the vessel is, as I have found in conversa- tion with sufferers, not very extensively known, though recognised as a valuable resource by many. Its efficacy sug- gested to me the view that visual impression disturbances are largely concerned in the production of sea sickness. Another method of preventing sea sickness, which I have practically tested and found most valuable, is that consisting in the complete abolishment of vision for the time being by bandaging the eyes, and thereby shutting out the possibility of visual disturbances. This method involves careful appli- cation of a bandage over the eyes before starting on the voy- age. The plan in question answers extremely well in the large majority of cases. It is generally necessary for the pa- tient to lie down in order to ensure proper adjustment of the bandage. Incidentally the patient under these circumstances gets the benefit of the horizontal position (an old remedy), and it may, of course, be said that if the bandage and the horizontal position be both employed, the benefit sustained is as likely to be due to the position as to the bandaging. Besides, I have known several cases where bandaging the eyes without lying down has proved to be preventive of sea sickness. The results obtained by the experiments which have been related are such as to show that whatever else may be the cause of sea sickness, visual disturbance impressions have a great degree of importance in the etiology of this distressing