OCR Text |
Show VE VE VE a Vine at forty four Feet four Inches in Dif4 The Sap will move any Way by the Ate tance from the Root, pufh’d up Sap with the traction of the f»me Capillary Tubes, and of the Leaves, fhewn by the Peripiration Inches eleven Feet Columnofthirty a Force of of Water. Branch of an Apple-tree, w hich drew up Moi. Healio fhews, by a nice Experiment, that fture plennfully at the tmall End: Alfo bya the Sap doesnot come indifferently through all Tree which throve, rhe) its Root was taken the Interjices of the Wood, butis confin’d to out of the Ground, receiving its Nourifhment its proper Veffels. only from twoother Trees to w hich it was in- ‘The Fibres or Capillary Tubes, out of the arched, and from whieh it was fufpended ; bleeding Seaton, cannot protrude the Sap be- and likewile by a Bough,with two Branches yond their Orifices in the Seétion of the Stem; cut off from a Tree 3 one Branca of which out but affifted by the Perfpiration of the Leaves, of the Water, preterved its V erdure, and rethe Sap will rité in that very Branch, which ceived its Nourifhment from the. ctl r Brancle will imbibe Water, if ic was cut off, and a immers'd in Water, w ia another Boughof ‘Tube applied to it, with Water pour’d in; the {ame Sort, without that Help, immediately nay, it would alfo imbibe Water at the {mall _wither'd. End. ‘ ti By another Experiment he provedchiefly, that there is a lateral Motion of the Sap thro’ IV. Experiments foewing the ready lateral Veffels, whereby ie Pogt dina Ca He cut four long Notches, our ae f ther (but looking towards the feveral Cardi Stem, as well as fromthe Stem tothe Branches, Points)ina prettylarge Branch, whofe Section, with an Account of fome Experiments relating fomeInches below the faid Notches, was imto the Circulation and Non-circulation ofthe Sap. ™mersd in Water ; and found that bythe Attraction of the Fibres, and Perfpiration of the The Analogy there is in manyrefpedts between Plants and Animals, has given Occafion to feveral ingenious Perfons to imagine, thar Leaves, the Moifture rofe plentifully, notwith. ftanding that the Continuity | of the greateft Part Gfnot all) the longitudinal Fibres was the Sap muft circulate in Plants, as the Blood deftroy’d by thofe deep Notches. does in Animals: and being fond of this new Hypothefis, they have contented themfelves The lateral Motion mayalfo be deduced from obferving, that Branches. will growout with a few Experiments that feem to confirm the Notion ; and inftead of making a fufficient of Roots, and thrive very well; and thatEiders, Sallows, Willows, Briers and Vines will grow Numberof Experiments and Obfervations, and comparing them impartially, they have fup- by putting either End of a Stem or Branch to the Ground, ae ply’d the reft by Conjectures, and endeavour’d He obferves, that thereis, indeed, an alter- to fupport their Hypothefis by other new Suppofitions. Pate receding and progreffive Motion of the Sap, which recedes when cold Weather and [t is upon this Account they have fuppos’d Rain fucceeds hot Sun-fhine, the Trees then particular Veffels (like Arteries) to carry up imbibing the Rains and Dews whichfall upon the Sap from the Roots to the Extremities or the Leaves; but upon the Returnofthe hot Leaves, and others (like Veins) to bring down Weather, the Perfpiration is renew’d, and the the Sap back again to the Roots, imagining the Sap Tifes again. former to come down between the Bark and the Wood: But they did not confider, thata _Thisis fufficient to account for Fe/Jamine and the Paffion-tree receiving a gilded Tin@ture be- ; Plant is very differently nourifh’d from an lowthe gilded inoculated Bud ; which bas beep Animal, and therefore requires a very different given as an Inftance of the Circulation of the Mechani{m and Structure for its Growth and Support. ‘The Reverend Mr. Hales has difprov’d the above-mentioned Opinion, by feveral Experiments and Obfervations; the chief of which Sap: But the J/ex grafted on the Englifp Oak, as it keeps (whilft the Oak sheds) its Leaves in Winter, fhews that the Sap does not circulate. 7 V. Experiments whereby to prove, tl at & are thefe that follow. great Quantity of Air is infpired by Plants. t. Having cut a long Notch in a growing Branch which had Leaves on, he obferv’d that the Notch was moift at the Bottom towards the Root, and not at the Top. : ae a. He makes it appear on this Head, that Plants imbibe a great deal of Air, not only that which comes up with the Sap from the VE upon which the Air went up into the Branch ‘ being moft difficultly brought together, out of the Tube, as appear’d by the rifing of “ which, upon Contract, were moft ftrongly Waterinto the ‘Tube. * united. And (Query 80.) denfe Bodies by 2. A Cylinder of Birch of about } of an ‘* Fermentation, rarefy into feveral Sorts of Inch diameter, with the Bark on, cemented in “ Air; and this Air, by Fermentation, and the Middle to the Top of an Air-Pump Re- “ fometimes without it, returns into denfe ceiver, fo as to fill up the Hole at the Top of “ Bodies.” the faid Receiver upon the Plate of the Air- Pump ; then in working the Pump, Air came out at the Bottom of the faid Cylinder (bubbling up through the Water in the Veffel) whether erect or inverted, cemented clofe on the Top-fection or not, and whether the old Eyes in the Sides were cemented up, or left bare, the Bark itfelf being previous to the Air; but then it took in lefs Air than when theold Eyes and upper Seétion were open, 3. When Water (pour’d into a cylindrick Glafs fix’d over the Receiver) cover'd that Part of the Wood which was out of the Re- Motion of the Sap, and confequently the lateral Fibres communicate with one anoth Communication of the Sap-Veffels ; the free Paffaze of it from the (mail Branches towards the | ceiver, no Air came through the Bottom; and when the Water was taken away from covering the upper Part of the Wood, the Airdid not come in throughthe Bottom, till the Top of the Cylinder of Wood had its Bark well dry’d. The Reverend Mr, Haies, from the Confi- deration of this and fome of his own Expeiments, concluded, that there muft be Air not only in an elaftick, but in a fix’d State, in Vegetabjes and other Subftances, and therefore that the Air-pumpwould not be fufficient to get all the Air out of Bodies: For which Reaion he contrived Ways ofgetting the Air out of feveral Subftances, by Fire (diftilling them) and Fermentation, and made ufe of a very ingenious, but fimple and certain Method, of meafuring the Quantity of Air generated from (or abforb’d by) the feveral Kinds of Bodies, upon which he made Experiments. The Defcription of his Hydroftatical Gages, and the Manner ofhis making his Experiments, not being to be thanin his own Words, a 4. He obferves with Dr. Grew, that the Mouths of the Air Vefels are vifible in the Leaves of Pines, and in the Trunks of feveral Plants, with a Microfcope; and in fome even without a Glafs. 5. In making Experiments upon young Shoots, as their Veffels are full of Sap, he did not find that the Air paffed into or through them (the Airin them probably being become fixed ) but it came in freely at the Roots, apply’d to the Air-pump in the fame Manner as in the Piece of Birch. In order to make a at tity of Air, which arofe from Diftillation or Fufion, I firft p whichI intended to diftil into a ¢ (Figure 4.) and then at a it the Glats Veffel 2b, which cious at b, with a Hole in the Bott I bound a Bladder over the Ce was madeof 'Tobacco-pipe Clay and Bean flower, well mix’d with fome Hair, tying over all, four fimall Sticks, which ferv’d as Splinters to ftrengthen the Joint; fometimes inftead of the Glafs Veffel a b, I VI. A Specimen of an Attempt to analyze made ufe of a large Bolt-head, which had the Air, by the Reverend Mr. Stephen Hales, around Hole cut, with a red-hot iron Ring at by a great Variety of Chimio-Statical Experiments, which fbew in bow great a Proportion Air is wrought into the Compofition of animal, the Bottom of it; through which Hole was put one Leg of an inverted Syphon, which reach’d up as far as z: Matters being thus vegetable and mineral Subjtances; and withal, how readily it refumes its former elaftick State, en in the Diffolution of thofe Subftances it is eugag'dfrom them. prepar'd, holding the Retort uppermoft, I immers’d the Bolt-head into a large Veflel of Water, to a, the Top of the Bolt-head ; as the Water rufh’d in at the Bottomof the Bolt-head, the Air was driven out through the The excellent Mr. Boyle, among his many Difcoveries, found that Air was producible from Vegetables, by putting Grapes, Plums, Goofeberries, Cherries, Peafe, and feveral other Sorts of Grain into exhaufted and unexhaufted Receivers, where they continued feveral Days, emitting great Quantities of Syphon, when the Bolt-head wasfull of Water to 2; then I clos’d the outward Orifice of the Syphon, with the End of my Finger, and at the fame time drewtheotherLegof it out of the Bolt-head, by which Means the Water continued upto z, andcouldnot fubfide, while it was in the Water, the Veffel Air. But Mr. Boyle did not fhew the Way x x; which done, I lifted the Veffel x x to know exaétly, how much Air a certain with the Bolt-head in it out of the Water, Quantity of vegetable Subftance will pro- and ty’d a waxed Thread at z, to mark the 2. He made the fame Experiment with ano- Earth (the Earth containing Air both in an ther Branch fet in Water, which imbibed the Liquor at a tranfverfe Section below the Notch, and found the Notch as before. 3. He obfery’d, that in the Spring the Sap ¢laftick and in a fix’d State) but alfo take It!" through the old Eyes and Bark, efpecially 4° Night, when the Plants are in an imbibing State. : ee duce. The incomparable Sir I/azac Newton (Query 31. ofhis Opticks) obferves, “‘ That true pera manent Air arifes by Fermentation or Heat, from thofe Bodies which the Chymifts call Height of the Water, and then approach’d the Retort gradually to the Fire, taking Care to skreen the whole Bolt-head from the Heat of the Fire. so ts ‘The Defcent of the Wate Wood, and that chiefly in Vines; and thatifa faid Affertion, are chiefly thefe, viz. “ jixed, whofe Particles adhere by aftrong fhew’d the _Sums of th “ Attraction, and are not therefore feparated Air, and of the M rifes plentifully between the Bark and the Ringlet of Bark be takenoffall round in bleed- The Experiments wherebyhe proves ™ 1. An open, empty Glafs Tube fet upright, ing, Trees, the Bleeding abates moft in the had an Apple Branch cemented inits upper upper Part of the bare Place, End, the other End fét in a Veilel of spe " and rarefied without Fermentation. Ex f The Expanfion of x “ Thofe Particles receding from one ano- lower Part of the Retc " ther with the greateft repulfive Force, and red-hot, was at a Mf > ; nearly to to the Apacity |