254 



KNOWLEDGE. 



July, 1913. 



might think from reading the advice given by some 

 writers. 



Those connected with the Nervous System are very 

 important. Nervous fear or association of ideas 

 will produce nausea without being on board a ship. 

 I know of one lady who has made several voyages to 

 India, on each occasion suffering much from sickness, 

 who dare not venture to a dock or wharf, as on 

 seeing the shipping violent nausea is produced. 

 Apart from such remarkable effects as this, nervous 

 anticipation of sickness or of danger from the sea 

 is a potent predisposing cause. Again, persons who 

 are generally neurasthenic, though without particular 

 reference to the sea, are usually bad subjects ; while 

 with those who have had brain injury or are liable to 

 epilepsy the sea will, as a rule, have an easy victory. 

 So inconsequent a thing as a nervous headache is a 

 predisposing cause of some importance. In fact, 

 any condition of the nervous system which is not 

 perfectly normal is liable to render the person under 

 it a prey to mal-de-mer. 



Those connected with the Ship. The ship itself is 

 important, not only as an exciting, but also as a 

 predisposing cause. A ship which is a bad sea boat, 

 and takes heavy seas aboard, one in which the 

 vibration is great, or which has a marked list, often 

 induces sickness, when much worse weather with 

 more actual motion on a better sea boat will not do 

 so. This result is no doubt due to nervous influences 

 at work, such as apprehension of danger from the 

 noise of large quantities of water falling on the upper 

 decks, and many other sounds which are more 

 marked on a badly found ship than on a well-found 

 one. 



The Exciting Cause is mainly the motion of the 

 craft on a rough sea. This motion is communicated 

 through a special sense to the brain, and thence to 

 the stomach as a secondarily affected organ. The 

 exciting cause, however, is not quite so simple as it 

 may appear at first sight. Thus we find that a 

 pitching motion produces sickness much more 

 quickly than a rolling one ; that a person accustomed 

 to the long, slow movements of a liner on great 

 oceans may easily succumb to the short motion of a 

 small ship in land-locked seas. It is found if one 

 lies down on going aboard, or when a storm is 

 blowing up, that sickness can often be averted ; and 

 also that if the weather becomes gradually worse 

 passengers can generally stand it who would 

 certainly be ill if they were subjected to a sudden 

 storm or went straight from dry land to a boat on 

 rough water. 



It is, in my opinion, due to a complete misunder- 

 standing of the true cause of sea-sickness that so 

 few cases have been relieved and remedies of little 

 or no value have been prescribed. Most people 

 seem to have taken it for granted that, since 

 vomiting and nausea are prominent symptoms, the 

 disease is due to gastric disturbance. As well might 

 it be said that vomiting in the case of a tumour of 

 the brain is due directly to gastric trouble. 



It will be well here to review the various theories 

 put forward before taking up that which I consider 

 to be the true cause. 



There can be no doubt that symptoms of gastric 

 disturbance are the most prominent, and, to the 

 casual observer, or the scientific one who has not 

 seen a great deal of this complaint, they appear to 

 be the only ones. Those — and they are many — who 

 hold that such symptoms are primary maintain that 

 the motion produced by the ship creates a dis- 

 turbance of the stomach and its contents, which sets 

 up a feeling of nausea, followed in due course by 

 vomiting. It is not clear why a particular movement 

 should affect the mucous membrane of the stomach 

 in this way, or why the motion of pitching should 

 have a greater effect than that of rolling. Much 

 confusion would be avoided if it were remembered 

 by those who advance this theory that there are 

 many persons whose digestive organs are weak or 

 easily affected by any unusual condition. In these 

 cases, no doubt, sickness at sea is set up, and 

 stomachic medicines do good. To arrive at the 

 truth the exceptional must be eliminated and the 

 average insisted on ; otherwise cases could be found 

 to bear out apparently an} - , even the most extrava- 

 gant, theory. 



The theory that while the gastric disturbance is 

 the primary one the brain has something to do with 

 the origin of the sickness, but rather as a predis- 

 posing than exciting element, is held by some. 



Some hold that in a sluggish liver, which reacts 

 on the stomach, we have the true and only cause 

 which is responsible for sea-sickness. Such a view 

 leaves inexplicable many of the symptoms associated 

 with the condition. 



The theory of imagination is advanced to show 

 that the primary nausea and the secondary vomiting 

 are figments of a diseased imagination, and if persons 

 so afflicted went on board ship determined not to be 

 sick they would probably not suffer. This savours 

 rather too strongly of Christian Science to be worthy 

 of consideration. 



Zing is of opinion that sea-sickness is due to a 

 high degree of cerebral anaemia, induced by the 

 pitching of the ship, caused by some obscure action 

 of the vasomotor centres comparable to the mode of 

 action of the emotions. It is doubtful if the brain is 

 anaemic during sea-sickness ; the good effects of the 

 bromides point to the reverse. He also holds that 

 the stomach is not directly concerned in the act of 

 vomiting, which he considers Nature's method of 

 replenishing the depleted cerebral circulation. The 

 vasomotor centres are certainly disturbed, as evi- 

 denced by the flushing and subsequent chilliness 

 experienced in sea-sickness. The disturbance I 

 believe to be due to the emotion of fear, since 

 this and profound depression are symptoms of the 

 disorder. Such disturbances are but symptoms, and 

 by no means account for all phenomena of the 

 condition. 



There are some who hold that it is through the 



