Euphrof. As alfo, I fuppofe, from any animal, or vegetative Subftances.

Cleon. They contain much greater Quantities of Air; fome Specimens of which, I fhall now give you. -I

take this new-laid Egg, and put it in the Jar of Water under the Receiver, and upon turning the Winch,-you fee many fine Streams of Air rifing from the Pores of the Egg.As I continue to work the Pump, you fee many more of these äerial Jets arife.Obferve now the Pores of the Egg emitting the Air in innumerable fmall Bubbles, which gives it a very pleasant Appearance.--After this, as the Vacuum proceeds, you find the Egg expanded by the Rarifaction of the internal Air, fo as to be rendered fpecifically lighter than it was. You fee it move, and roll about, and feems, as it were, to endeavour to rife to the Top, and is therefore but very little heavier than Water,

-I turn the Cock, and let the Air in, and you fee the Streams and Bubbles all difappear at once.

I

Euphrof. Thefe Things are extremely entertaining. could not have imagined there could have been fo much Air contained in an Egg, or, that there had been such evident Pores in the Shell.--I fuppofe, that, in like Manner, if a whole Animal were to be immers'd, one might fee the Air iffue from the Pores of his Skin.

Cleon. That may be eafily experimented in a small Bird, plucked of its Feathers, and put under Water.-In vegetable Subftances of every Kind thefe Experiments fhew a furprizing Quantity of Air, as I fhall inftance in this Apple, that is juft now gathered from the Tree.—— I connect it with a Piece of Brafs, and fink it to the Bottom of the Water, having firft made a few Holes in it with a Pin.Then I cover it with a Glass, and as I begin to exhauft, you fee the Air arife from the different Parts of the Apple, but particularly from the Holes made with the Pin.- -As I further proceed, you fee the Air rifing from the Pores of the Apple in many fenfible Streams. As the Air is ftill farther rarified, the Streams are more and more numerous, and the Quantity of Air fo great, as to make a perfect Ebullition on the Top of the Water.- -If the Vacuum remain for any Time, you will fee the Bubbles and Streams of Air continue so long, and if you look at the Gage, you will fee the Mercury

fink in Proportion to the Air, produced from the Apple, and this as often as the Experiment is repeated.—At last I turn the Vent-fcrew, and the Air difappears at once.

Euphrof. This is a noble Experiment, truly! and I fancy, from what I have now obferved, that a fhrivelled Apple would alfo make a very pretty Appearance in the

Water.

Cleon. It will, indeed; and I ufually fhew the Experiments on both, when they can be had.—I have a withered Apple of the beft Kind for this Purpofe, which I fhall now put into the Water, and you will fee the Difference between this and the other.-When turning the Winch, you fee many Streams of Air arife, though not fo large and numerous as before; but you obferve, at the fame Time, the Effect of the internal Air, by expanding the Apple, and caufing the Wrinkles to difappear by Degrees,-till at laft, it has attained to the full Extent of its Skin, and looks nearly as full and fresh, as when firft gathered from the Tree.

Euphrof. By this Experiment and the former, I am thoroughly convinced of the Nature and Difference of Fruit, with regard to the Air they contain. I fee from thence, how pervious they are to this neceffary Element. I learn too from hence, how neceffary the Air is to preserve them, and to give them that Poignancy and pleasant Flavour, which they have when recent and fresh gathered; and that Mellownefs, and Rottennefs, proceed from fome Deficiency either in Quantity or Quality of the Air in Fruit of the laft Year's Growth.

Cleon. You reafon very well on the Experiments you have feen; but, by another Experiment or two that will follow, you will find, that Fruit of any Kind is beft preferved without any Air at all; and that it is the conftant Action of the Air that deftroys the natural Texture by an inceflant and infenfible Fermentation in the Parts, which difpofes them, by very flow Degrees, to become putrid, or rotten.

Euphrof. If this be the Cafe, one would think Methods might be contrived, by Means of your Pump, to keep the Fruit from the Air as long as you pleafe, which would be a fine Improvement for the Paftry-cooks, in regard to their Tarts and Pics,

Cleon. It would fo; and in an Age or two more, our Pofterity may wonder how it came to pass, that the great Philofophers of this Age fhould fhew fo bad a Tafte, and be content with difcovering the Means of living well, but leaving them to enjoy it. You will find Mr. Boyle's Works abound with Inftances of this philofophical Method of preferving Fruit; many of which, if we may judge from his Experiments, far exceed the poor Provifion of Pickles and Confections.

Euphrof. You make me very attentive to what you now fay. This is a very interefting Point with me, and I muft infift upon your being extremely particular in gratifying my Curiofity and Enquiries upon this Head; and in the firft Place, pray, tell me how you proceed in this Affair of preferving Fruit.

Cleon. For this Purpose, we have Glaffes, blown of a proper Form, to hold a Pint, or Quart, or any Quantity you please, of any Kind of Fruit; as Peaches, Nectarines, Apricots, Apples, Pears, Plums, Cherries, Goofeberries, Currants, &c. The Mouth, or Neck of these Bottles is therefore larger or fmaller, in Proportion to the Size of the Fruit you intend to preferve, and their Form must be conical, or tapering inwards.In the next Place, Corks must be nicely fitted to the Orifices of thefe Glaffes. Then, having filled the Bottle with Fruit, clean and dry, you put in the Cork, and tie a wetted Bladder over it, fo that, when dry, it may firmly adhere to the Cork and the Glafs, and by this Means render the whole Air-tight.After this, you place Sealing-wax on one Part of the Cork, and with a red hot Iron Wire burn a Hole through the fame, that thereby a Paffage may be given for the Air to be drawn out from the Fruit.

Euphrof. Such an Experiment I should be extremely glad to fee. Have you got any fuch Glafs by you, Cleonicus? If you have, I can fupply you with Fruit.

Cleon. I have feveral of them, and your Garden produces fome of the fineft Fruit to be preferved in this Way. A few of your Nectarines and Peaches, gathered dry, will fuffice for an Experiment at prefent, and afterwards you may make use of this Procedure for any other Sort or Quantity of Fruit you please.

Euphrof. I will, this Minute, ftep into the Garden.

Did you ever fee finer Fruit?Where is your Glass? Have you one that will take any Fruit fo large?

Cleon. This one will do it, and was made for receiving thi Sort of Fruit. What you have brought are fine indeed; but you will find, that the Age of Fruit will little appear in their Countenance in February next.—— You obferve, I car fully put them into the Glafs till it is filled-T en, this Cork, prepared, readily fits the Top of the Recipient, which I prefs down very hard.Then, with this ignited Wire, I burn a Hole through the Sealing-wax and Cork; and here I must cease from purfuing this Experiment any farther at prefent; the Sun muft lend us his Aid, and co-operate in the enfuing Part. Belides that, I have already tired your Attention with so long a Lecture. To-morrow, if the Morning be clear, as foon as the Sun-beams enliven the Parlour, I fhall then wait on that glorious Luminary and yourself; so at this Time, Adieu.

DIALOGUE

XII.

The Expériments on the AIR-PUMP continued.

T

Euphrofyne.

HIS Morning answers to my Wishes ; the glorious Sun promifes Success to our Designs, and the Entertainment you gave me with the preceding Experiments, have greatly excited my Expectations for the Remainder; but none takes with my Curiofity fo much, as the Experiment under Confideration.- -I fee here ftands the Bottle with the Fruit ftill.

Clean. Yes, and in a few Minutes time the Sun will dart its Beams into the Room. This convex Glass will converge the Beams of the Sun into so small a Compafs, as to make them burn any combustible Object that is placed in the denfer Part, or the Focus of the Rays.Thus, you fee, I hold the Glafs in the Sun-beans, and a Piece of brown Paper in the Focus.-You fee it begins to fume, and immediately kindles into a Flame.

Euphrof. A furprising Experiment indeed! The Heat

that fets that Paper on fire, will certainly melt the Wax on the Cork, which now, I prefume, you are ready for.

Cleon. I waited only for the Sun, and now I take the Pump, and place it in its Beams,-and exhauft the Air from the Fruit.-Then, with the Glafs, you fee, the Sun-beams are easily thrown on the Wax, which inftantly melts, and clofes up the Hole ;-and now is your Fruit prepared for keeping at your Pleasure.

Euphrof. I thank you, Cleonicus, for this. I fhall fet it by, with an Intent to prove how far your philofophical Discoveries can be applied to improve thofe natural Delicacies of Life.—I am afraid I have detained you too long with this Experiment. Pray, what have you next to follow?

Cleon. As thefe Experiments are defigned to illuftrate the Properties of natural Bodjes, with regard to Air, I fhall now entertain you with one or two more, about vegetable Subftances; and you must know, that Plants are organized Bodies, or confift of Veffels, of different Kinds, for circulating Fluids from the Earth and Air, through all the Parts; for they, no more than, Animals, can fubfift without a conftant Refpiration of Air.-Many Experiments we shall hereafter fhew, to demonftrate this; but at present shall entertain you with one or two on the Pump. You fee, I have a long Piece of Wood, fixed into a Socket of Brafs:-This I place on the open Receiver, fo that the lower End is immerfed in a small Jar of Water, and exhausting the Air from the Surface of the Water, you fee how plentifully it rushes through the Veffels of the Wood to fupply the Deficiency.-I put my Thumb on the upper Part of the Wood, and you fee no more Air appear through the Water.-When I take off. my Thumb, you again fee the Air rufhing thro' the Pores of the Wood into the Water; and thus alternately, as I put my Thumb on or off.By this Experiment, you fee, that any Piece of Wood is pervious to the Air, and that thofe Air-veffels run through the Length, or Subftance of the Tree.

Euphrof. This is a very pleasant Experiment, and entertains the Eye, at the fame Time as it improves the Mind. I knew not before, that Air was fuch a neceffary Article in Plants, or that they were thus conftructed, to circulate that wonderful Fluid.