483 Concerning the Injluentt of the Moon upon the Atmofphere cj the Earth, 



earths a£l on each other in the manner of thcfe folvents, becaufe wc find lime take files 

 from pot-afh ; this lafl: yields alumine to magnefia, and lime vitrifies barytes, as barytes 

 vitrifies filex. 



Laftly, the phenomena which may give rife to refemblances of this kind, ought not to 

 be confidered but as the effefls of a more general caufe j that attraction of near bodies, 

 which in the inequality of its relations forms the bond of natural combinations, and the 

 power of the inftruments employed by chemiftry to dlfunite them. 



III. 



Concerning the Injluence of the Moon upon the Atmofphere of the Earth. By Cit. Lam ark *. 



HE moon has certainly a great influence on the ftate of the atmofphere of the earth. 

 For if that univerfal gravitation which produces the attraftion between the moon and the 

 earth, can occafion the flux and reflux of the fea, how can it be denied, that the fame 

 caufe fliould not produce a kind of flux and reflux of the atmofpheric air, continually dif- 

 placed by the fucceflive changes in the diflances and pofitions of thefe bodies which gravi- 

 tate towards each other ? This influence of the moon on the atmofphere of the earth has 

 never been doubted ; but no perfon has yet, to my knowledge, examined the nature of 

 that influence, in a manner fufllciently precife, to exhibit its true cfl"e£ls. Philofophers 

 have been too defirous of difcovering in certain afpefts, namely, the fyzigies and qua- 

 dratures, the indicating points of the changes which this planet incefiantly produces in the 

 terreftrial atmofphere. 



I have direfted my obfervatlons for a great number of years to examine the variations 

 in the ftate of the atmofphere, in order to difcover, if poflTible, the principal caufes, efpe- 

 cially thofe which adl moft regularly in thefe phenomena ; and I have at length fucceeded 

 in difcovering the following principles : 



1. It is in the elevation and depreflion of the moon, above or below the equator, that 

 we muft feek for the caufes of thofe regularly variable effeCts which it produces on our 

 atmofphere. 



2. The determinate circumftances which augment or dimlnifh the influence of the moon 

 in its diflirent declinations are, the apogees and perigees of this planet, its oppoCtions and 

 conjundtions with the fun, and laftly, the folftices and equinoxes. 



It is well known that after every time that the moon crofles the equator, it remains for 

 about fourteen days in the hemifphere it has entered, whether auftral or boreal. Every 

 lunar month therefore prefents one revolution of the moon in the zodiac, which may be 

 divided into two diftinft parts, and which produce or caufe two particular atmofpheric 

 conftitutions. I call one of thefe the boreal conftitution, namely, that during which the 



* Soc, Philomath, No. 15, p.' 117. 



moon 



