CLASS IV. 3. 2. 1. OF ASSOCIATION. 439 



ORDO III. 



Retrograde Associate Motions. 



GENUS II. 



Catenated with Sensitive Motions. 

 SPECIES. 



1. Nausea idealis. Nausea from disgustful ideas, as from 

 nauseous stories, or disgustful sights, or smells, or tastes, as well 

 as vomiting from the same causes, consists in the retrograde ac- 

 tions of the lymphatics of the throat, and of the oesophagus, and 

 stomach; which are associated with the disgustful ideas, or sen- 

 sual motions of sight, or hearing, or smell, or taste; for as these 

 are decreased motions of the lymphatics, or of the oesophagus, or 

 stomach, they cannot immediately be excited by the sensorial 

 power of painful sensation, as in that case they ought to be in- 

 creased motions. So much sensorial power is employed for a 

 time on the disgustful idea, or expended in the production of 

 inactive pain, which attends it, that the other parts of the asso- 

 ciated chain of action, of which this disgustful idea is now be- 

 come a link, are deprived of their accustomed share; and there- 

 fore first stop and then invert their motions. Owing to defi- 

 ciency of sensorial power, as explained more at large in Sect. 

 XXXV. 1. 3. 



2. Nausea a conceptu. The nausea, which pregnant women 

 are so subject to during the first part of gestation, is owing to the 

 reverse sympathy between the uterus and stomach, so that the 

 increased action of the former, excited by the stimulus of the 

 growing embryon, which I believe is sometimes attended with 

 sensation, produces decreased actions of the latter with the dis- 

 agreeable sensation of sickness with indigestion and consequent 

 acidity. When the fetus acquires so much muscular power as 

 to move its limbs, or to turn itself, which is called quickening, 

 this sickness of pregnancy generally ceases. 



M. M. Calcined magnesia. Rhubarb. Half a grain of 

 opium twice a day. Recumbent posture on a sofa. 



3. Vomitio vertiginosa. Sea -sickness, the irritative motions of 

 vision, by which we balance ourselves, and preserve our perpen- 

 dicularity, are disturbed by the indistinctness of their objects; 

 which is either owing to the similarity of them, or to their 



