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26 ESSAYS AND OBSERVATIONS 
tion, that all the refraCtion and reflexion 
which the whole depth of our atmofphere 
produces is mach lefs than what happens - 
at one furface of water ; and confequent- 
ly, the heat produced in our atmofphere, 
by the immediate action of light upon its 
mutt likeways be much lefs than what is 
raifed in water. ‘The air feems to have 
the greateft part of its heat communicated ° 
to it from the opaque vapours which 
float in it and the general furface of fea 
and land to which it is contiguous. 
Boe CP ae ee 
On the filver-like Appearance of Drops of 
Water on the Leaves of Colewort. 
16, IT is common to admire the volu- 
bility and luftre of drops of rain that lie 
on the leaves of colewort and fome other 
vegetables ; but no philofopher, as far as 
I know, has put himfelf to the trouble of 
explaining this curious phenomenon. Up- 
on infpe@ing them narrowly, I find, that 
the 
