A I R 
but thefe are of fmall efteem ; for the double Rofe 
Campion being a fine flower, has turned the others 
out of molt. fine gardens. The Angle forts propagate 
fail enough by the feeds, where they are permitted to 
fcatter, for the plants come up better from felf-fown 
feeds, than when they are fown by hand, efpecially if 
they are not fown in autumn. 
The fort with double flowers, which is a variety of 
the former, never produces any feeds, fo is only pro- 
pagated by parting of the roots ; the belt time for this 
is in autumn, after their flowers are paft ; in doing of 
this, every head which can be flipped off with roots 
fliould be parted. Thefe fliould be planted in a bor- 
der of frefh undunged earth, at the diftance of fix 
inches one from the other, obferving to water them 
gently until they have taken root •, after which they 
will require no more, for much wet is very injurious 
to them, as is alfo dung. In this border they may re- 
main till fp ring, when they fliould to be planted into the 
borders of the flower-garden, where they will be very 
ornamental during the time of their flowering, which 
is July and Auguft. 
The fifth fort grows naturally upon the Helvetian 
mountains ; this is a low plant, with woolly leaves •, 
the flower-ftem rifes near a foot high ; the flowers ' 
grow in umbels on the top of the ftalk, which are of 
a bright red colour. It flowers in July, and the feeds 
ripen in September. It muff have a fhady fituation, 
and will thrive belt in a moift foil. 
AIR [Jer, Lat. ’A vp, of A dsl feTv, becaufe it always 
flows ; or as others, of ofapi, to breathe.] By air is 
meant all that fluid expanded mafs of matter which 
furrounds our earth, in which we live and walk, and 
which we are continually receiving and calling out 
again by refpiration. 
The fubftance whereof air confifts, may be reduced 
to two kinds, viz. 
1. The matter of light or fire, which is continually 
flowing into it from the heavenly bodies. 
2. Thofe numberlefs particles, which is in form ei- 
ther of vapours, or dry exhalations, are raifed from 
the earth, water, minerals, vegetables, animals, &c. 
either by the folar, fubterraneous, or culinary fire. 
Elementary air, or air properly fo called, is a certain 
fubtile, homogeneous, elaftic matter, the bafis or fun- 
damental ingredient of the atmofpherical air, and that 
which gives it the denomination. 
Air therefore may be confidered in two refpe&s ; ei- 
ther as it is an univerfal affemblage, or chaos, of all 
kinds of bodies ^ or as it is a body endued with its 
own proper qualities. 
1. That there is fire contained in all air is demonftra- 
ble, in that it is evident, that there is fire exifting in 
all bodies, and to this fire it is that air feems to owe 
all its fluidity ; and were the air totally divefted of 
that fire, it is more than probable that it would coa- 
lefce into a folid body] for it is found by many expe- 
riments, that the air condenfes and contracts itfelf fo 
much the more, the lefs degree of warmth it has ; 
and, on the contrary, expands itfelf the more, accord- 
ing as the heat is greater. 
2. In refpeCt of exhalations, air may be faid to be a ge- 
neral collection of all kinds of bodies •, for there are no 
bodies but what fire will render volatile, and difperfe 
into air ; even falts, fulphurs, and Hones, nay and 
gold itfelf, though the heavieft and moll fixed of all 
bodies, are convertible into vapours by a large burn- 
ing-glafs, and are carried on high. 
Thole floating particles, thus raifed from terreftrial 
bodies, are moved and agitated by the fiery particles 
divers ways, and are diffufed through the whole at- 
mofphere. 
Of the matters thus raifed in the atmofphere, thofe 
which come from fluid bodies, are properly called va- 
pours, and thofe from folid or dry ones, exhalations. 
The caufe of this volatility and afcent is the fire, 
without which all things would fall immediately dov/n 
towards the’center of the earth, and remain in eternal 
reft. 
Thus, if the air be full of vapours, and the cold luc- 
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ceeds, thefe vapours before difperfed are congregated 
and condenfed into clouds, and thus fall back again 
into the form of water, rain, fnow, or hail. 
From the time of the entrance of the fpring till au- 
tumn, the evaporation is conftant ^ but then it begins 
to fail, and in the winter ceafes, to lay up frefh mat- 
ter for the coming feafon. 
And thus it is that frofty winters, by congealing the 
waters, and by covering the earth with a cruft, and 
thus imprifoning the exhalations, make a fruitful 
fummer. 
And this feems to be the reafon why in fome coun- 
tries, where the winter is feverer than ordinary, the 
fpring is more than ordinary fruitful ; for in fuch 
places the exhalations being pent up a long time, are 
difeharged in the greater quantity, when the fun makes 
them a paffage ; whereas, under a feebler cold, the 
flux would have been continual, and confequently no 
great flock referved for the next occajfion. 
This vaporous matter then being at length received 
into the atmofphere, is returned again in the form of 
rain, a forerunner of a chearful crop. 
As the fun retires, the cold fucceeds, and thus the 
diverfity of the feafons of the year depends on a change 
in the face of the cruft of the earth, the prefence of 
the air, and the courfe of the fun. * 
And hence we conceive the nature of meteors, which 
are all either collections of fuch vapours and exhala- 
tions, or difperfions thereof. 
The fubtiler oils are always rifing into the air. Now 
two clouds, partly formed of fuch oils, happening to 
meet and mix, by the attrition, the oil frequently takes 
fire, and hence proceed thunder, lightnings, and 
other phenomena, which may be farther promoted 
by the difpofition of the clouds to favour the exci- 
tation. 
And hence arife great and hidden alterations in the 
air, infomuch that it fhall be now intenfely hot, and 
raife the fpirits perhaps to eighty-eight degrees in a 
thermometer •, and yet, after a clap of thunder with 
a fhower, it fhall fall again in a few minutes no lefs 
than twenty or thirty degrees. 
It is therefore impoffible to pronounce what the de- 
gree of heat will be in any givfen place at any time, 
even though we know ever fo well the places and po- 
fition of the fun and planets with refpeCt to us, fince 
it depends fo much upon other variable things, no 
ways capable of being afeertained. 
The lower the place, the clofer, denfer, and heavier 
is the air, till at length you arrive at a depth where 
the fire goes out ; fo that miners, who go deep, to 
remedy this inconvenience, are forced to have re- 
courfe to an artificial wind, raifed by the fall of wa- 
ters, to do the office of the other air. 
Now, confidering the air as fuch a chaos, or affem- 
blage of all kinds of bodies, and a chaos fo extremely 
liable to change, it muff needs have a great influ- 
ence on vegetable bodies. 
3. Air confidered in itfelf, or that properly called air. 
Betides the fire and exhalations contained in the cir- 
cumambient atmofphere, there is a third matter, 
which is what we properly mean by air. 
To define the nature of it would be extremely diffi- 
cult, inafmuch as its intimate affections are unknown 
to us •, all we know is, 
1. That air is naturally an homogeneous fimilar 
body. 
2. That it is fluid. 
3. That it is heavy. 
4. That it is elaftic. 
5. That it rarefies by fire, and contracts by cold. 
6. That it is compreflible by a weight laid thereon, 
and rifes, and reftores itfelf upon a removal of the 
fame : all which circumftances fliould incline it to 
coalefce into a folid, if fire were wantihg. 
1. Air is divided into real and permanent, and ap- 
parent or tranfient. 
Real air is not reducible by any compreflion or con- 
denfation, or the like, into any fubftance befides air. 
Tranfient air is the contrary of the former, and by 
cold. 
2 a 
