152 
ON CHEMISTRY. 
inches of the surface of the sea in twenty-four hours, a square mile 
of surface would evaporate daily 6914 tons. The Mediterranean sea 
was supposed to lose, each day, 5280 millions of tons; and Dr. 
Thompson was led to infer, that the average volume of water raised 
from the whole surface of the earth, amounts annually to ninety-four 
thousand, four hundred and fifty cubic miles. 
Now all this may he very wild and visionary, but the learned 
Bishop of Llandaff, Dr. Watson, founded his calculations upon more 
familiar experiments, and he thence arrived at the conclusions which 
I proceed to state. He placed glass vessels of known capacity upon 
the surface of the ground, when that was in very different states of 
dryness; and found that even in periods of drought, under a burning 
sun, the quantity of vapour yielded was prodigious. He estimated 
the quantity of pure water yielded by a single meadow of an acre’s 
surface in twenty-four hours, to be equal to 1600 gallons. 
Two-thirds of this inconceivable volume of water, which, be it re¬ 
collected, if reduced to a state of vapour, must occupy fully 1400 
times the original bulk of the liquid—two-thirds of this volume are 
supposed to be precipitated in the form of rain. A portion also may 
be condensed as dew, but what becomes of the remainder of the va¬ 
porised water ? I suggest the reply, fearless of any conclusively phi¬ 
losophical refutation, that it is converted by solar electric agency into 
the pure respirable air of the atmosphere, whose volume it thus re¬ 
plenishes and maintains in its integrity. 
To corroborate this hypothesis, which by most, may perhaps be 
denounced as fanciful, and utterly devoid of foundation, I appeal to the 
following phenomena. 
1. Phenomena of Vapour and Steam. 
The production of vapour is now admitted to be attended with 
electricity; it is in fact, a process of developement by the agency of 
heat, or combustion, whereby the particles of water are separated, 
and kept apart, by a repulsive power. If steam be projected into 
the air from a boiling vessel, or even from the lungs, by forcible ex¬ 
piration, it assumes various forms, according to the existing state of 
the atmosphere. If that be cold and damp, the vapour remains dis¬ 
tinctly visible for some seconds; yet even in such a state, when also, 
the.,concomitant of a fog or mist affords proof of the abundance of 
atmospheric humidity, the steam rolls about, disperses, and is lost, 
amidst the accumulated vapour. If, on the contrary, the atmosphere 
be dry, and buoyant, (be the temperature what it may,) the steam 
rises, expands, breaks off, into light, irregular masses, and speedily 
disappears. Every action, every form it assumes, denotes repulsion 
