This vital air is received by animals into their lungs, gives them
their heat, and communicates a red colour to their blood; when
animals die for want of vital air, their blood is always found
black.

From what I have said, it is evident, that in large and populous
towns, where combustion and respiration are continually performed on
a large scale, the air must be much less pure than in the country,
where there are few of these causes to contaminate the atmosphere,
and where vegetables are continually tending to render it more pure;
and if it was not for the winds which agitate this element, and
constantly occasion its change of place, the air of large towns
would probably soon become unfit for respiration. Winds bring us the
pure air of the country, and take away that from which the vital air
has been in a great measure extracted; but still, from the immense
quantity of fuel which is daily burnt, and the number of people
breathing in large towns, the air very soon becomes impure.

From the greater purity of the air in the country, proceeds the rosy
bloom found in the rural cottage, which we in vain look for in the
stately palace, or the splendid drawing room. Here then are reasons
for preferring the country, which no one will dispute, and whenever
it can be done, such a situation ought always to be chosen in
preference to a large town: this cannot be better enforced than in
the words of Dr. Armstrong.--

'Ye, who amid the feverish world would wear
'a body free of pain, of cares a mind;
'fly the rank city, shun its turbid air;