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common red letter-wafer touched by the flame of a 
candle. But as in this paper I have laboured (and 
I hope not without fuccefs) to fhew you, that fome 
properties of folar heat are fufficient to account for 
the elevation and fupport of vapours j fo in another 
letter I propofe nearly to demonftrate to you, that 
the eledtric aether is far from having any fhare in the 
production of this important phenomenon. 
Front, 
Gentlemen, 
Litchfield, Your very humble Servant, ' 
Mar. 20. 1757. 
Erafmus Darwin. 
LETTER II. 
To the very honourable and learned the President 
and Members of the Royal Society. 
Gentlemen, 
Head May 5, p VERY theoretical inquiry, whofe 
D bafls does not reft upon experiments, 
is at once exploded in this well-thinking age ; where 
truth, under your patronage, has at length broke 
thro’ thofe clouds, with which fuperftition, policy, 
or parade, had overwhelmed her. But experiments 
themfelves, gentlemen, are not exempted from fal- 
lacy. A ftrong inventive faculty, a flne mechanic 
hand, a clear unbiafled judgment, are at once re- 
quired for the contrivance, conduct, and application, 
of experiments ; and even where thefe are joined 
