68 
OX THE PHENOMENON OF DEW. 
is very generally received, being adopted by some of the first meteorolo¬ 
gists of the day, whose assent may be taken as proof that the Doctor’s 
opinion is no longer hypothetical, but founded on demonstrable facts. 
I presume not to question the correctness of the Wellian ideas, nor 
do I take up the pen to criticise or dispute the truth of any account of 
the phenomenon heretofore published; all I intend to do in this paper 
is, to describe^ the natural appearance of dew, as it is seen by every 
attentive observer, in every season, and under every circumstance of 
wind and weather, and which will serve to confirm all previous accounts 
which are true, or correct, perhaps such as are irrelevant. 
From the earliest pages of recorded knowledge, we read not only of 
the morning and evening dew, but of the falling dew. Historians, 
and particularly poets, whether ancient or modern, in alluding to this 
beautiful meteor, always describe it as falling . To account for its 
precipitance and condensation, it was long held as probable, that ex¬ 
halations from the earth during the day were raised, and sustained in 
the atmosphere by the heat of the sun while above the horizon; but 
as soon as set, and his beams of heat and light withdrawn, the exhala¬ 
tions, becoming heavier as they are cooled by the night air, fall again to 
the earth, forming those pearl-like globules of the purest water attached 
to the point of every blade of grass and tender leaf, and to the salient 
angles on the margin of every leaf. 
Dew is more or less abundant according as the air is clear and cloud¬ 
less, and more or less calm. When wind prevails, no dew is formed 
on exposed plants, but on those only which grow in sheltered places; 
neither is any formed, whether windy or calm, on grass-land parched 
by long-continued drought, though, at the same time, it is most copious 
on moist ground, and on the margins of lakes and rivers. 
Dew-drops are not distributed indiscriminately, but on healthy vege¬ 
tation only : dead or sickly plants carry no dew. If a healthy plant of 
grass, for instance, be growing in the midst of a thousand sickly ones, 
the first only will be dewed. This is often strikingly visible in gar¬ 
dens, and particularly in the business of forcing. In a vinery, the 
leaves of all the vigorous-growing trees are, on mornings, beautifully 
fringed with dew; but on weak and stunted trees no drops appear. 
In hotbeds, when the young cucumber or melon plants are progressing 
prosperously, they are seen to be finely embellished with dew-drops 
when uncovered on mornings. In both these cases the dew is formed 
under every degree of temperature between thirty-five and ninety 
degrees of Fahrenheit’s scale. 
In the open air, when the sky is cloudy, and a strong breeze of wind 
prevails, no dew is formed on any exposed plant or place; but if any 
