CLASS IV. 2. 4. OF ASSOCIATION. 



ORDO II. 



Decrtafed Affbciate Motions, 



GENUS IV. 

 Catenated with External Influences* 



As the difeafes, which obey fol r or lunar periods, commence 

 with torpor or inactivity, fuch as the cold paroxyfms of fevers, 

 the torpor and confequent pain of hemicrania, and the pains 

 which precede the fits of epilepfy and convulfion, it would feem, 

 that thefe difeafes are more generally owing to the diminution 

 than to the excefs of folar or lunar gravitation ; as the difeafes 

 which originate from the influence of the matter of heat, are 

 much more generally in this country produced by the defect 

 than by the excefs of that fluid. 



The periodic returns of fo many difeafes coincide with the 

 diurnal, monthly, and annual rounds of time 5 that any one, who 

 would deny the influence of the fun and moon on the periods 

 of quotidian, tertian, and quartan fevers, muft deny their effect 

 on the tides, and on the feafons. It has generally been believed, 

 that folar and lunar effect was exerted on the blood ; which 

 was thus rendered more or lefs (limulant to the fyftem, as de- 

 fcribed in Seel. XXXII. 6. But as the fluid matter of gravita- 

 tion permeates and covers all things, like the fluid matter of 

 heat 5 I am induced to believe, that gravitation afts in its medi- 

 um ftate rather as a caufa fine qua non of animal motion like 

 heat 5 which may diforder the fyftem chemically or mechanical- 

 ly, when it is dimini(hed ; but may neverthelefs ftimulate it, 

 when increafed, into animal exertion. 



Without heat and motion, which fome philofophers ftill believe 

 to be the fame thing, as they fo perpetually appear together, the 

 particles of matter would attract and move towards each other, 

 and the whole univerfe freeze or coalefce into one folid mafs. 

 Thefe therefore counteract the gravitation of bodies to one cen- 

 tre ; and not only prevent the planets from falling into the fun, 

 but become either the efficient caufes of vegetable and animal 

 life, or the caufes without which life cannot exift ; as by their 

 means the component particles of matter are enabled to flide over 

 each other with all the various degrees of fluidity and repul- 

 fion. 



As the attra&ion of the moon countervails or diminifhes the 

 terrene gravitation of bodies on the furface of the earth ; a tide 



rifes 



