ftr* 



24 R. M Bache on Seasickness. 



a descent, and at the same time remember, how small the motion 

 of a long gliding rise or descent is, as compared to much that 

 one is subjected to at sea — how much less violent. The effect 

 upon the observer is produced simply by the difference of motion 

 ignorance of the extent to which it is going — by the idea 

 defined motion. When one's senses are educated in the 

 novel condition of existence at sea, the motion is no longer un- 

 defined. A ship could make no movement which would not be 

 accompanied by a corresponding idea of space passed through. 

 There is no motion at sea which by habit will not cease to appear 

 undefined, but if it were possible for a ship to mount heaven- 

 wards, and to sink rapidly near to the bottom of the sea in 

 alternate movements, it is my belief, that the hardiest sailor 

 would become sea-sick. 



The summary of what I have attempted to demonstrate is this, 

 that sea-sickness is not the result of motion "per se," nor of the 

 appearance of motion " per se," but is the result of the senses 

 •' violating the habitual conception of contrasted effects of mo- 

 tion " and producing on the brain the idea of undefined motion. 

 When the senses are educated to form cooperating and agreeing 

 measures of the novel condition of existence at sea, nausea ends. 

 If they never formed these measures nausea would never end. 



For another proof of this theory, take the case of an infant 

 Instances of children in arms being sea-sick are very rare.* 

 A child certainly feels the motion, that is to say its body is sub- 

 ject to the motion equally with that of the oldest passenger. But 

 a child undergoes motion without /ee?m^ it. It sees too, without 

 perceiving. In its case nothing conflicts. It is as ready to be 

 rocked on the billows as in its cradle. Its youth precludes the 

 possibility of its having any habitual conception of motion from 

 the education of the senses, and if it feels any sensation, that sen- 

 sation is at variance with nothing. As soon as children begin to 

 " take notice," as it is called, the education of the senses begins 

 and thus we find, that children shortly afterwards, at the age of 

 two and three years, are attacked by sea-sickness, but they recover 

 long before adults are secure from it. The case of a blind man, 

 because he cannot see, and consequently cannot perceive, is not 



