Chapter VII: Madam,

Having made mention in my last of your _Authors_ opinion, _That Air is in its nature Cold_, I thought it fit to take a stricter view of the temper of Air, and to send you withal my own opinion thereof. First of all, I would fain know, what sort of Air your _Author_ means; for if he thinks there is but one sort of Air, he might as well say, that there is but one sort of Animals, or Vegetables; whereas yet there are not onely different sorts of animal and vegetable kind, but also different particulars in one and the same sort: As for example; what difference is not amongst Horses, as between a Barb, a Turk, a Ginnet, a Courser of _Naples_, a Flanders-horse, a Galloway, an English-horse, and so forth? not onely in their shapes, but also in their natures, tempers and dispositions? The like for Cows, Oxen, Sheep, Goats, Dogs, as also for Fowl and Fish, nay, for Men. And as for Vegetables, What difference is there not between Barly and Wheat, and between _French_-barly, _Pine_-barly, and ordinary Barly; as also our _English_-wheat, _Spanish_-wheat, _Turkish_-wheat, _Indian_-wheat, and the like? What difference is there not amongst Grapes, as the _Malago, Muscadel_, and other Grapes, and so of all the rest of Vegetables? The same may be said of the Elements; for there is as much difference amongst the Elements as amongst other Creatures. And so of Air: for Air in some places, as in the _Indies_, especially about _Brasilia_, is very much different from our air, or from the air that is in other places: Indeed, in every different Climate, you shall find a difference of air, wherefore 'tis impossible to assign a certain temper of heat or cold to air in general. But although my sense and reason inform me, that air in its own nature or essence is neither hot nor cold, yet it may become hot or cold, by hot or cold motions; for the sensitive perceptive motions of Air may pattern out heat or cold; and hence it is, that in Summer, when as heat predominates, the air is hot; and in Winter, when as cold predominates, the air is cold. But, perhaps, you will say, air may be cooled by moving it with a Fan, or such like thing which can make wind; wherefore it follows, that air must needs be naturally cold. I answer, That doth not prove Air to be in its nature cold: for this moving or making of wind may contract or condense the air into cold motions, which may cause a cold wind, like as Ventiducts, where the air running thorow narrow Pipes makes a cold wind. The same may be done with a mans breath; for if he contract his lips close, his breath will be cold, but if he opens his mouth wide, his breath will be warm. Again: you may say, that rain is congealed by the coldness of the air into Snow, Hail and Ice. I answer; Frost, Ice, Snow and Hail, do not proceed from the coldness of the air, but rather the coldness of the air proceeds from them; for Ice, Snow, and Hail, proceed from cold contraction and condensation of a vaporous or watery substance; and, as Frost and Snow cause air to be cold, so Thunder and Lightning cause it to be hot, so long as they last. Thus, _Madam_, though Air may be altered either to heat or cold, yet it is neither hot nor Cold in it self. And this is all for the present that I can say concerning the Temper of Air; I conclude, and rest,

Madam,

_Your constant Friend,_

_and faithful Servant._