22 R. M. Bache on Sea-sickness. 



the uniformity of the motion to which the body is subjected 

 when swinging. All these certainly give a most accurate idea 

 of the segment of a circle which the body is describing in the air. 

 Nausea can be produced in a swing, but it requires very little 

 education of the senses to enable a person to bear the motion, 



I have been told by a person who attempted to prepare himself 

 for a sea voyage by using a swing, that the process was entirely 

 unavailing — yet I doubt very much, whether the motion to which 

 one is subjected at sea, is often greater than can be attained in a 

 well constructed swing. But the motion of a swing is quite uni- 

 form — that at sea far from it, and the failure of the swing to 

 inure a person to unequal motion, shows that it is not motion 

 which affects us, but inequality of motion, and that it is not the 

 mere mass of flesh and digestive organs which are alone con- 

 cerned, but other elements as appurtenances of the body de- 

 mand our consideration, and as I hope to prove, merit it, far 

 more than the mere body and stomach, which becoming diseased 

 only react. If it be said, that animals, such as horses and dogs, 

 become sea-sick, and yet have no such nice senses as we have, 

 excepting perhaps scent ;— I answer by saying, that a horse is 

 always terrified at movement in which he does not see the cause, 

 even terrified at perfectly noiseless movement. What is it which 

 prompts a young dog to jump at all hazards from a vehicle in 

 rapid motion, even when driven by his own master, and what 

 makes him eventually delight in riding? Preconceived ideas of 

 motion when violated bring terror to both horse and dog. The 

 conditions of novel motion, once accepted, the senses are recon- 

 ciled and habit is the result. If then we allow these animals to 

 possess habitual conception of motion, they must be affected at 



degree. The tumbler pigeon precipitates itself with a revolving 

 motion towards the earth, but does not appear to be at all af- 

 fected by the motion which its body has undergone. If the same 

 bird is taken in the hand and its head placed under one of its 

 wings and it is then whirled around, it may be placed on a ta- 

 ble, and during a few moments it will appear lifeless. Aquatic 

 birds of the greatest vigor in flight, and habituated to floating on ^ 

 stormy waves, often become nauseated on the decks of vessels. 



L^t us now consider the motions at sea, A ship rolls, plunges, 

 seems to pause, then dart, and every movement brings the pvis- 

 senger increased uneasiness. There is no precedent in his expe- 

 rience for such movement. If he possesses sight, the view of 

 objects is at variance with all that he has been habituated to in 

 other motions. If he is blind, his mental conception — the pic- 

 ture in his mind — is equally at variance with his habitual con* 

 ception. In a few days, in either case, the person would be 

 indifferent to the motion. He will have learned, in the mean- 



