CLASS IV. 2. 1. 10. OF ASSOCIATION. 403 



lence as to refift venefecfion, opiates, bark, blifters, mucilages, 

 and all the ufual methods employed in coughs. It was for a 

 time fuppofed to be the hooping-cough, from the violence of the 

 action of coughing ; it continued two or three weeks, the pa- 

 tient never being able to fleep more than a few minutes at once 

 during the whole time, and being propped up in bed with pil- 

 lows night and day. 



As no fever attended this violent cough, and but little expec- 

 toration, and that of a thin and frothy kind, I fufpected the 

 membrane of the lungs to be rather torpid than inflamed, and 

 that the faline part of the mucus not being abforbed ftimulated 

 them into perpetual exertion. And laftly, that though the 

 lungs are not fenfible to cold and heat, and probably therefore 

 lefs mobile, yet, as they are neverthelefs liable to confent with 

 the torpor of cold feet, as defcribed in Species 6 of this Genus, 

 I fufpected this torpor of the lungs to fucceed the gout in the 

 feet, or to aft a vicarious part for them. 



10. Vertigo rotatoria. In the vertigo from circumgyration 

 the irritative motions of vifion are increafed ; which is evinced 

 from the pleafure that children receive on being rocked in a 

 cradle, or by fwinging on a rope. For whenever fenfation arif- 

 es from the production of irritative motion with lefs energy 

 than natural, it is of the difagreeable kind, as from cold or hun- 

 ger ; but when it arifes from their production with greater en- 

 ergy than natural, if it be confined within certain limits, it is of 

 the pleafurable kind, as by warmth or wine. With thefe in- 

 creafed irritative motions of vifion, I fuppofe thofe of the ftom- 

 ach are performed with greater energy by direct fympathy ; but 

 when the rotatory motions, which produce this agreeable verti- 

 go, are continued too long, or are too violent, ficknefs of the 

 llomach follows 5 which is owing to the decreafed action of that 

 organ from its reverfe fympathy with the increafed actions of 

 the organ of vifion. For the expenditure of fenforial power by 

 the organ of vifion is always very great, as appears by the fize 

 of the optic nerves ; and is now fo much increafed as to deprive 

 the next link of aiTociation of its due (hare. As mentioned in 

 Species 6 of this Genus. 



In the fame manner the undulations of water, or the motions 

 of a fhip, at firft give pleafure by increafing the irritative mo- 

 tions belonging to the fenfe of vifion ; but produce ficknefs at 

 length by expending on one part of the alfociated train of irri- 

 tative actions too much of that fenforial power, which ufually 

 ferved the whole of it ; whence ibme other parts of the train ac- 

 quire too little of it, and perform their actions in confequence too 

 feebly, and thence become attended with difagreeable fenfation, 



It 



