To Mr. BRADLEY, F. R. S. SIR, A S we have often had Opportunities of converfing about the Difference of Soils, and of the Temperature of Air, requir'd for the Production and Nourishment of Vegetables, I here fend you, as near as I can remember, the Sum of our Arguments, with fome Remarks I have made upon them. To begin then; you feem to be of Opinion that it was not the Soil or Earth it felf which afforded fufficient Provifion for the feveral Plants or Vegetables; that there were refiding in every Earth, fome agreeable Juices to nourish Plants of different Kinds; and as thofe Juices were more or lefs abundant in that Earth, or had different Qualities, fo the Vegetables planted in it would be more or lefs vigorous: Thefe Juices, or Salts, you fuppos'd were furnish'd by the Air, and put in Action by the Sun; to prove which you referr'd me to the following Experiment, faid to be Helmont's, related by Mr. Boyle, who dry'd two hundred Pounds of Earth, and planted a Willow of five Pounds Weight in it, which he water'd with Rain, or diftill'd Water; and to fecure it from any other Earth getting in, he cover'd it with a perforated Tinn Cover. Five Years after, weighing the Tree, with all the Leaves it had born in that Time, he found it to weigh one hundred fixty nine Pound, three Ounces; but the Earth was only diminish'd about two Ounces in its Weight. This Experiment I found, as you directed, in Mr. Derham's Phyf. Theol. p. 61, p. 61. I have made fome others of the fame Kind, and find the Plant has little more Use of the Earth it ftands in, than the keeping it fix'd and steady; but then, as Earths are more or lefs binding, the Salts or Juices proper for Vegetation have lefs or more Liberty to act. From Experiments of this Kind one might come to a reasonable Judgment how much a Tree encreases in every Year of its Growth, and how much it improves in Value; but I fhall leave that to be confider'd more particularly by your felf, only offering this Hint, that the Earth, after the Tree is drawn from it, must be weigh'd in the fame State it was in when the Tree was planted in it: The faireft Way, I think, is to make it as dry as poffible, in an Oven, at both Times; this would likewife lead us into many curious Speculations, as that the fine Body of the Air fhould become denfe as Water in the Veffels of the Tree, and from that State be fix'd, and become folid as the Wood of a Tree. I think it is almost demonstrative, that the vegetable Nourishment is principally in the Air, from the foregoing Experiment; the two Ounces of Earth loft, might perhaps remain on the Sides of the Cafe the Tree was planted in, or upon its Roots, or in the Weight of two hundred Pounds I think two Ounces may easily be loft, unless both the Scales and the Weigher are very exact; or in the baking or drying of the Earth, there might be two Ounces more of Moisture found in that Quantity of Earth, one Time than another. Thus fuppofing 'tis Air which feeds and nourifhes Plants, and from the Inftance you have given me of the Tree Sedum, which will take Root, and live, without Earth or Water, for feveral feveral Years; I come to confider how much the different Changes and Alterations of Air work upon Vegetables. In the Example of a Piece of the Sedum Arborefcens, hung up at Mr. Fairchild's, at Hoxton, which you fay fhoots out its Roots when the Air thickens and tends to Rain; this I have fo far experienc'd, that I am perfuaded it is conftantly fo; and I have try'd other Sedums, which proportionally do the fame; but it is difficult to determine whether the different quantity of Moisture, contain❜d in each of the kinds of them, may not, upon one certain Temperature of Air, be difpos'd to exert it felf to the utmost of its Power in each respective Plant; or whether, according to the different Textures of the feveral Plants, every one is not impower'd in its own Way to receive a certain impulfe, or diftinct nourishing quality from the Air, which the reft cannot equally fhare of. In fome Conversation I have had with you, I remember you was of Opinion, that the Veffels of each diftinct Plant were different from those in the others, and that thofe Veffels were in every Plant capable of filtring the Juices they receiv'd from the Air or Earth, in fuch a manner as to alter their Parts, and vary their first Powers: To which you offer'd me as Examples; firft, that 'twas poffible to make Plants live in almost any Air or Soil, provided the Air it felf was not too much pent up or stagnated; from whence I fuppofe that all Bodies of Earth are more or lefs capable of imbibing the fluent Air, and of attracting fuch Salts as either the Air can give, or the Earth is capable of receiving; when thefe Salts (however they come into the Earth) are lodg'd in Grofs, or in a Body, the different Strainers or Veffels of the feveral Plants growing C upon upon that Spot of Earth, thus impregnated with Salts, alter thofe Salts or Juices according to the feveral Figures or Dimenfions of their Strainers; fo that one Plant varies in Taste and Smell from others, tho' all draw their Nourishment from the fame Stock lodg'd in the Earth. But I remember you remark'd farther, that Earths themfelves being of different kinds, fome forts could not take in fo many of the nourishing parts of the Air as others, and therefore the fame fort of Plant could not grow in every Soil with the like Vigour; that is, because every fort of Earth has not the fame Fund of Salts, or elfe that every Earth is not equally capable of diftributing to the Plants growing in it the Salts it contains, with the fame Freedom. Again, your Inftance that Thyme and other Aromaticks being planted near an Abricot Tree, would deftroy that Tree, helps to confirm that every Plant does not draw exactly the fame fhare of Nourishment. Virgil, in his Georgics, gives us good Hints of the different Soils and Situations neceffary for Plants of different kinds; Nec verò Terræ ferre omnes omnia poffunt : and that Earths of several kinds will imbibe certain qualities from the Air: Mr. Boyle affures us, that the Earth or Ore of Allum being robb'd of its Salt, will in Tract of Time recover it, by being 8 being expos'd to the Air; which intimates fomething more than I have obferv'd before, that every distinct fort of Earth has even a Power of its own, of extracting from the Air Salts of particular qualities, or elfe of altering the common Salts of the Air, according as its Parts are diffe rently fram❜d or order'd. The other Remarks which I have made in this way, I fhall take another Opportunity of communicating, and am, SIR, Yours, &c. And that I may omit nothing which may tend to the Pleasure and Profit of the Hufbandman, or thofe curious Perfons that admire a Country Life, I fhall take Occafion to mention how far the good Management of Bees may contribute to their Mafter's Advantage, after giving fome Account of the Economy of thofe wife Labourers; for I think the Profit of their Wax and Honey, tho' it is very confiderable, does not carry its full Value with it, if we difregard the Virtue, Diligence, and Contrivance of the Bees, who work it for us; which we may obferve with great Pleasure, by Means of the Glafs or Box Hives, which are fo order'd that the Honey may be taken without deftroying the Bees: But whether it is for the Mafter's Advantage to leave them alive, when they are robb'd of their Honey, or the greatest part of it, is yet a Doubt; for 'tis a Query whether the fame Bees work two Summers, or even live fo long, and if not, the Food they destroy in the Winter is fo much Lofs: However, I have been told that a fwarm of Bees accidentally fix'd a Colony in a large Wine Cask, C 2 which |