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B O O K I.

Of the Out-Works of the Terraqueous
Globe; the Atmosphere, Light, and
Gravity.

CHAP. I.
Of the Atmosphere in general.

HE Atmosphere, or Mass of Air, Vapours and Clouds, which surrounds our Globe, will appear to be a matter of Design, and the infinitely wife Creator's Work, if we consider its Nature and Make («), and its Use to the World (*).

i. Its Nature and Make, a Mass of Air, of subtile penetrating Matter, fit to pervade other Bodies, to penetrate into the inmost Recesses of Nature, to excite,, animate, and spiritualize} and in short, to be the very Soul of this lower World. A thing consequently

2. Of greatest Use to the World, useful to the Life, the Health, the Comfort, the Pleasure, and Business of the whole Globe. It is the Air the

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(a) Mundi pan est Aer, er qitidem necest'aria: Hie est enim qui cœlum terramque connetfit, &C. Senec. Nat. Qu. 1. 1. c. 4.

(b) Ipse Aer nobiscum -videt, nobiscum audit, nobiscum senat; nihil enim torum fine et fieripotest, &c. Cic. de Nat. Deor. 1. 2. c. 33.

whole whole Animal World breatheth, and liveth by; not only the Animals inhabiting the Earth (c) and

Air,

(c) As the Air is of absolute Necessity to Animal Life, so it is necessary that it should be of a due Temperament or Consistence; not foul, by reason that suffocateth: not too rare and thin, because that sufficeth not; with Examples of each of which, I shall a little entertain the Reader. In one of Mr. Hawksbee's Compressing Engines, 1 closely shut up"a Sparrow without forcing any Air in; and in less than an Hour the Bird began to pant, and be concerned; and in less than an Hour and half to be sick, vomit, and more out of Breath; and in two Hours time was nearly expiring.

Another I put in and compressed the Air, but the Engine leaking, I frequently renewed the Compressure; by which means, (although the Bird panted a little after the first Hour,) yet after such frequent Compressures, and Immiffion of fresh Air, it was very little concerned, and taken out seemingly unhurt after three Hours.

After this 1 made two other Experiments in compressed Air, with the Weight of two Atmospheres injected, the Engine holding tight and well; the one with the Great Titmouse, the other with a Sparrow. For near an Hour they seemed but little concerned; but after that grew fainter, and in two Hours time sick, and in three Hours time died. Another thing I took notice of, was, that when the Birds were sick and very restless, I fancied they were somewhat relieved for a short space, with the Motion of the Air, caused by their fluttering and shaking their Wings, (a thing worth trying in the Diving-Bell). I shall leave the ingenious Reader to judge what the cause was of both the Birds living longer in compressed, than uncompressed Air; whether a less quantity of Air was not sooner fouled and rendred unfit for Respiration, than a greater.

From these Experiments two Things are manifested; one is, that Air, in some measure compressed, or rather heavy, is necessary to Animal Life: Of which by and by. The other, that fresh Air is also necessary': For pent up Air, when overcharged with the Vapours emitted out of the Animal's Body, becomes unfit for Respiration. For which Reason, in the Diving-Bell, after some time of stay under Water, they are forced to come up and take in fresh Air, or by some such means recruit it. But the famous Cornelius Drebell contrived not only a Vessel to be rowed under Water, but also a Liquor to be carried in that Vessel, that would supply the want of fresh Air. The Vessel was made for King James I. It carried twelve Rowers, besides the Passengers. It was tried in the River of Thames; and one of the Persons that was in that submarine Navigation Was then alive, and told it one, who related the Matter to our famous Founder, the Honourable, and most Ingenious Mr. Boyl. As to the Liquor, Mr. Boyl faith, he discovered by a Doctor of Physick, who married Drebell's Daughter, that it was used from time to time when the Air in the submarine Boat was clogged by the Breath of the Company, and thereby made unfit for Respiration; at which time, by unstopping a Vessel full of this Liquor, he could speedily restore to the troubled Air such a proportion of vital Parts, as would make it again for a good while fit for Respiration. The Secret of this Liquor Drehell would never disclose to above one Person, who himself assured Mr. Boyl what it was. Vid. Boyl. Exp. Phys. Mech. ef the Spring of the Air, Exp. 41. in the Digres. This Story I have related from Mr. Boyl, but at the fame time much question whether the Virtues of the Liquor were so effectual as reported.

And as too gross, so too rare an Air is unfit for Respiration. Not to mention the forced Rarefactions made by the Air-Pump, in the following Note; it is found, that even the extraordinary natural Rarefactions, upon the tops of very high Hills, much affect Respiration. An Ecclesiastical Person, who had visited the high Mountains of Armenia, (on which some fancy the Ark rested) told Mr. Boyl, that whilst he was on the upper part of them, he was forced to fetch his Breath oftner than he was wont. And taking notice of it when he came down, the People told him, that it was what happen'd to them when they were so high above the Plane, and that it was a common Observation amoiig them. The like Observation the same Ecclesiastick made upon the top of a Mountain in the Cevennes. So a learned Traveller, and curious Person, on one of the highest Ridges of the Pyrenees, call'd Pic de Midi, found the Air not so fit for Respiration, as the common Air, but he and his Company were fain to breath shorter and oftner than in the lower Air. Vid. Phil. Transatf. No. 63, or Low thorp's Abridg. Vol. l. p. xx6.

Such another Relation the learned Joseph Acosia gives of himself and his Company, that, when they passed the high Mountains of Peru, which they call Periacaca, (to which he faith, the Alps themselves seemed to them but as ordinary Houses, in regard of high Towers,) He and his Companions were surprised with such extreme Pangs of Straining and Vomiting, (not without casting up of Blood too,) and with so violent a Distemper, that he concludes he should undoubtedly have died; but that this lasted not above three or four Hours, before they came into a more convenient and natural Temperature of the Air. All which he concludes proceeded from the too great Subtilty and Delicacy of the Air, which is not proportionable to humane Respiration, which requites a more gross and temperate Air, Vid. Boyl,

Thu.s,

Air (</), but those of the Waters (e) too. Without it

most

Thus it appears, that an Air top Subtile, Rare and Light, is unfit for Respiration: Bin the Cause is not the Subtilty or too great Delicacy, as Mr. boyl thinks, but the too great Lightness thereof, which renders it unable to be a Counterbalance, or an Antagonist to the Heart, and all the Muscles miniftnng to Respiration, and the Diastole of the Heart. Of which fee Book 4. Chap. 7. Note 1.

And as our Inability to live in too rare and light an Air may discourage those vain Attempts of Flying and Whimsies of passing to the Moon, we. so our being able to bear an heavier State of the Air is an excellent Provision for Mens Occasions in Mines, and other great Depths of the Earth; and those other greater Pressures.made upon the Air, in the Diving-Bell, when we descend into great Depths of the Waters.

(d) That the Inhabitants of the Air, (Birds and Infects,) need the Air as well as Man and .otheriAnimals, is manifest from their speedy dying in top feculent, or too much rarefied Air; of which see the preceding and following Note/. But yet Birds and Insects (some B^irds at least) can live in a rarer Air than Man. Thus Eagles, Kites, Herons, and divers other Birds, that • delight in high Flights, are not affected with the Rarity of the Medium, as those Persons were in the preceding Note. So Insects bear the Air-Pumplong, as in the following Note/1

(<?) Creatures inhabiting the Waters need the Air, as well as other Animals, yea, and fresh Air too. The Hydrocanthari of all Sorts, the Nymphs, of Gnats, and many othe#^VaterInsects, have a singular Faculty, and an admirable Apparatus, to raise their back Parts to the top of the Waters, and take in fresh Air. It is pretty to fee, for Instance, the Hydrocanthari come and thrust their Tails out of the Water, and take in a Bubble of Air, at the tip of their Vagins. and Tails, and then nimbly carry it down with them into the Waters; and, when '» that is spent, or fouled, to ascend again and recruit it.

So Fishes also are well known to use Respiration, bypassing the Water through their Mouths and Gills. But Carps will live '*. 'out of the Water, only in the Air; as is manifest by the Expe* riment of their way of Fatting them in Holland, and -which hath been practised herein England, viz.. they hang them up in a Cellar, or some cool Place, in wet Moss in a small Net, with their H eads out, and feed them with white Bread soaked in Milk for many Days. This was told me by a Person very curious, and of great Honour and Eminence, whose Word (if I had leave to name him) no Body would question: And it being an Instance

most Animals live scarce half a Minute (/) j and others, that are the molt accustomed to the want of it, live not without it many Days.

And

of the Respiration of Fifties very singular, and somewhat out of the way, I have for the Reader's Diversion taken notice of it.

(/) By Experiments I made my self in the Air Pump, in September and Ottober, 1704; I observed that Animals whose •Hearts have two Ventricles, and no Foramen Ovale, as Birds, Dogs, Cats, Rats, Mice, e«. die in less than half a Minute counting from the very first Exsuction; especially in a small Receiver.

A Mole (which I suspected might have born more than other Quadrupeds) died in one Minute (without Recovery) in a large Receiver; and doubtless would hardly have survived half a Minute in a small Receiver. A Bat (although wounded) sustained the Pump two Minutes, and revived upon the re-admission of the Air. After that, he remained four Minutes and a nils and revived. Lastly, After he had been five Minutes, he continued gasping for a rime, and after twenty Minutes I re admitted the Air, bat the Bat never revived.

As for In/efts: Wasps, Bees, Hornets, Graflioppers, and LadyCows seemed dead in appearance in two Minutes, but revived in the open Air in two or three Hours time, notwithstanding they had been in Vacua twenty four Hours.

The Ear-ivig, the great Staphy linns, the great black lowsy Beetle, and some other Insects would seem unconcerned at the Vacuum a good while, and lie as dead; but revive in the Air, although* some had lain sixteen Hours in the exhausted Receiver.

Snails bear the Air Pump prodigiously, especially those in ■ Shells; two of which lay above twenty four Hours, and seemed not much affected. The same Snails I left in twenty eight Hours more after a second Exhaustion, and found one of them quite dead, but the other revived.

Frc-g\ and Toads bear the Pump long, especially the former. A large Toad, found in the House, died irrecoverably in less than six Hours. Another Toad and Frog 1 put in together, and the Toad was seemingly dead in two Hours, but the Frog just alive. After they had remained there eleven Hours, and seemingly dt:ad, the Frog recovered in the open Air, only weak, but the Toad was quire dead. The fame Frog being put in again for twenty seven Hours, then quite died.

The Animalcules in Pepper-Water remained in Vacua twenty four Hours. And after they had been exposed a Day or two to the open Air, I found some of them dead, some alive. '•'' W That

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