26 REMARKABLE EFFECTS OF SOL-LUNAR 



mospheric air, and the mode of their combination, 

 who will presume to limit or define its connection 

 with sol-lunar influence? Who will be so hardy 

 and so regardless of his own reputation as to pro- 

 nounce, without proof, that this influence has 7w 

 power to produce any change whatever in the na- 

 ture of this compounded iluid ; in the smallest de- 

 gree connected with useful knowledge; or neces- 

 sar}^ in any respect to be known ? 



fldli/. For the purpose of removing the obstacles 

 that arise from the intricacy and labour of astrono- 

 mical investigations, in which those who are em- 

 plo3"ed in the study and practice of medicine can 

 have no leisure to engage, it will be sufficient to 

 present a plain and simple idea of this power, with 

 the common changes to which it is liable, ab- 

 stracted from all the complicated circumstances by 

 which those changes are produced : The conside- 

 ration of which, though indispensibly necessary 

 for the nicer purposes of astronomy, are by no 

 means required for those of medicine and meteoro- 

 logy- ■ 



It was determined bvDz La Place* in 1790, 

 that the force of the moon to excite those perturba- 

 tions that manifest themselves on the surface of 

 our globe, by the elevation of the tides, is three, 

 and tiiat of the sun one. Assuming this as a foun- 

 dation, we have only to conceive that those two 

 quantities of power, sometimes assisting and some- 

 times counreracting each other according to the 

 varying positions in which they are placed, pro- 

 duce the corresponding changes that are observed 



* Asfrcnomie par Jerome Le Fkancais La Lande, Tome 

 III, Troisieme E<iilion Revue et Augmentee, additious et correc-. 

 tions, page 757- 



