46 
MEMOIR OP LAMARCK. 
most favourite studies. So comparatively limited 
is our positive knowledge of atmospheric pheno- 
mena, that a careful investigation of them alforded 
the prospect of new and important discoveries ; 
while the endless variety of appearances which 
they present, and the complicated influences which 
operate ' in producing them, offered a wide and 
interesting field for the exercise of that specu- 
lative kind off inquiry which Lamarck loved to 
indulge. "With his usual facility in such matters, 
he was not long in advancing a theory, according to 
which the atmosphere is regarded as resembling the 
sea, having a surface, waves, and storms ; it ought, 
likewise, to have a flux and reflux, for the moon 
ought to exercise the same influence upon it that it 
does on the ocean. In the temperate and frigid 
zones, therefore, the wind, which is only the tide of 
ihe atmosphere, must depend greatly on the decli- 
nation of the moon ; it ought to blow towards the 
pole that is nearest to it, and advancing in that 
direction only, in order to reach every place, travers- 
ing dry countries or extensive seas, it ought then 
to render the sky serene or stormy. If the influence 
of the moon on the weather is denied, it is only 
that it may be referred to its phases ; but its posi- 
tion in the ecliptic is regarded as affording pro- 
babilities much nearer the truth*. 
* On the Influence of the Moon on the Earth’s Atmosphere ; 
Journal do Physique , Prairial, an. vi. Most of Lamarck's other 
essays on Meteorology will be found in the periodical just 
named. 
