R. M. Bache on Seasickness. 19 



roborate and "vice versa." In the first case, nervous impression 

 was produced bj doubt in the mind of the observer as to whether 

 his body was or was not in motion, and in the second case, 

 bj the consciousness of motion of the body, which motion was 

 not felt. In neither case, did the senses keep pace, consequently 

 the nervous impression ensued, and consequently nausea. It ia 

 evident, although the sight was the agent in these results, that it 

 was only the agent, and it was the imagination which produced 

 the effects. Sight was the intermediary. It may be safely in- 

 ferred from the efiect of the appearance of motion in the two 

 cases just cited— that if a man believing himself in his senses, 

 should see a landscape glide by, he would become nauseated, yet 

 it is evident that the nausea would proceed from the involved 

 idea of motion — the idea that he might be in motion without 

 feeling it — for if he knew it was only the landscape which he 

 saw that was in motion, he would regard it with terror, but with- 

 out other sensation, and it would affect him as a passing train of 

 cars when he knew that his own body was at rest — that is, it 

 would not affect him at all, as far as nauseation is concerned. 



We see then, that the appearance of motion "per se " does not 

 nauseate, and we see too, how the nervous system is impressed 

 by the imagination so as to bring about nausea. 



The senses from the earliest infancy have grown up and been 

 educated together, to act in harmony. It requires habit to render 

 them capable of keeping pace together in a novel condition of 

 existence. The motion communicated to the body by riding in 

 a carriage, is by no means violent, notwithstanding which, per- 

 sons in early life, frequently become nauseated while thus riding. 

 This is merely because the sense of sight and the feeling of a cer- 

 tain motion have not been educated together. This I shall proceed 

 to show. It is well known, that persons perfectly habituated to 

 riding in a certain position in a carriage, object to riding with 

 the back towards the direction in which they are proceeding, on 

 the plea that it makes them sick to do so. It doubtless has that 

 effect, but it is impossible for the effect to be produced by the 

 mere motion in that position, for it is impossible in a carriage in 

 motion in the dark, to decide in what position one is sitting in 

 relation to the line of progress, unless some obstacle should inter- 

 pose, or the road should be so bad as to afford an equivalent to 

 a number of obstacles in the way, or unless the driving is of 

 such a character, by sudden turnings and abrupt increasing or 

 slackening of speed, as to indicate to the occupant of the carriage 

 ■ " 3n in which he must be sitting. In a word, in ordinary 

 3 of progress in a carriage, it is impossible in the dark to 

 deterrame in what position one is sitting. This is not generally 

 known. Experiment will prove my assertion to be true. 



It has been already shown, that the appearance of motion 

 *' per se" does not nauseate. How then is a person accustomed 





