We may easily conceive how this happens, if we examine the Case of the Diving Tub, how short a while a Man can live it, without a Supply of fresh Air; the occasion of which is, that when he has drawn in with his Breath, all the Grosser Parts from the Air enclos’d in the Tub, the rest grows hot and suffocating, by being too much rarified.
From whence I suppose, a Room of Nine or Ten Foot Cube, will contain Air enough to keep a single Man alive for one Day, but if two were to inhabit that Space for the same time, each would receive but half his Nourishment, and so both would be Sufferers; but a Room, perhaps, containing twice that Space, might well enough serve five People for a Day, supposing that all External Air was kept from Communication with such a Room, during the time the People were in it; for, as I have observ’d, that Air has certain Nourishing Qualities in it, for the Maintenance of Human Life; so when those Nourishing Parts are imbibed, and drawn in by the Lungs, the Air is return’d and flung out as invalid, and cannot be of Use a second Time to the same Person; an Example of which, we find very curiously demonstrated by Mr. Newyentyte; he tells us, that in making this Experiment, he discover’d that the same Nourishing Quality in the Air, which is necessary to maintain Human Life, is also necessary to maintain Flame, which he proves thus:
A lighted Candle being set under a Bell, closely fix’d upon a Table, will burn perhaps a Minute or two in Proportion to the Quantity of Air pent up with the Candle in the Bell; but as soon as the Quality in that Air, which is necessary to feed the Flame, is exhausted, the Candle goes out; this has been often try’d with the same Success; and we find, that by letting into the Bell some fresh Air, a little before the Candle should have gone out, it will still continue burning: And then to shew that this Quality in the Air is the same which feeds the Life in Humane Bodies, it was try’d, whether the Air, returning from the Lungs, would not have the same Effect upon the Candle, as the External Air had before, but it had not, the Candle went out at its usual Time: Thus, it seems, when we suck in Air for Breath, the Lungs takes what is necessary for the Nourishment of our Bodies, and returns back the rest.
After this we may naturally conclude, that where the Rooms, or Houses are small, there ought to be frequent Admissions of the External Air, but especially where those Rooms or Houses are too much crouded with People; and if it is supposed that the External Air is Infectious, the burning of Aromaticks, Gums, or Herbs, upon the letting in of fresh Air, is necessary.
From the foregoing Observations we may learn, that all Pestilential Distempers, whether in Animals or Plants, are occasion’d by poisonous Insects convey’d from Place to Place by the Air, and that by uncleanly Living and poor Diet, Humane and other Bodies are disposed to receive such Insects into the Stomach and most noble Parts; while, on the other Hand, such Bodies as are in full Strength, and are well guarded with Aromaticks, would resist and drive them away, but chiefly how necessary it is to allow the Body a Freedom of Air, and how to correct it if it is Infected.
And I shall conclude with some Memorandums taken from the Papers of a learned Gentleman, who in the time of the late Plague in London was curious enough to make his Remarks upon the Signs of that Distemper, and the Method of its Cure.
He tells, the Plague proceeds first from a corrupted and unwholsome Air.
The Second, is putrified Humours, hot Blood, caused by breathing in such corrupt Air; and if the Diet before were perverse, it fills the Body with superfluous Humours.
Concerning the common Fear of Infection, which makes many rich Men, which might and ought to maintain poor visited People; and some Physicians likewise, whose Duty it is to administer Physick to them, flee away, so that in time of great Infection we hear more cry out for want of Bread and necessary means, than for anguish of the Disease.
Hence also came that inhumane Custom of shutting up of Houses that are visited with Pestilence, dejecting their Spirits, and consequently making way for the Disease, and taking Men from their Labour, which is a digester of Humours, and a preserver of Health; and if the Disease be Infectious (as in their Opinion it is) it is plain Murder, to shut Men up in an infected and destroying Air.