CLASS IV. 3. 4. i. OF ASSOCIATION. 443 



ORDO HI. 



Retrograde Affbciate Motions, 



GENUS IV. 



Catenated with External Influences* 

 SPECIES. 



1 . Catarrhus periodicus. Periodical catarrh is not a very un- 

 common difeafe; there is a great difcharge of a thin faline mu- 

 cous material from the membranes of the noftrils, and probably 

 from the maxillary and frontal fmufes, which recur once a day 

 at exacl folar periods ; unlefs it be difturbed by exhibition 

 of opium-, andrefembles the. periodic cough mentioned below. 

 See Clafs I. 3. 2. i. It is probably owing to the retrograde ac- 

 tion of the lymphatics of the membranes affected, and produced 

 immediately by folar influence. 



2. Tuffis periodica. Periodic cough, called nervous cough, 

 and tuflis ferina. It feems to arife from a periodic retrograde 

 action of the lymphatics of the membrane, which lines the air- 

 cells of the lungs. And the action of coughing, which is vio- 

 lent for an hour or longer, is probably excited by the ftimulus 

 of the thin fluid thus produced, as well as by the difagreeable 

 fenfation attending membranous iuadivity ; and refembles pe- 

 riodic catarrh not only in its fituation on a mucous membrane, 

 but in the difcharge of a thin fluid. As it is partly reftrainable, 

 it does not come under the name of convulfion ; and as it is not 

 attended with difficult refpiration, it cannot be called aithma ; 

 it is cured by very large dofes of opium, fee a cafe and cure in 

 Sea. XXXVI. 3. 9. Clafs IV. 2. 4. 6. and feems immediately 

 to be induced by folar influence. 



3. Hyjleria a frigore. Hyfteric paroxyfms are occafioned by 

 whatever fuddenly debilitates the fyftem, as fear, or cold, and 

 perhaps fometimes by external moifture of the air, as all delicate 

 people have their days of greater or lefs debility, fee Clafs IV. 

 3. 1.8. 



4. Naufea pluvialis. Sicknefs at the commencement of a 

 rainy feafon is very common among dogs, who aflift themfelves 

 by eating the agroftis canina, or dog's grafs, and thus empty 

 their ftomachs. The fame occurs with lefs frequency to cats, 

 who make ufe of the fame expedient. See Seel. XVI. n. I 

 have known one perfon, who from his early years has always 



been 



