salutary qualities of it, and consequently of determining this question; since, from its effects on other animals, much may be inferred concerning its influence on the human frame.

Yours, &c.

PAUL GEMSEge.

P.S. It is not meant, by what is said above, to disparage Dr. Mead's book in the least, for it is an excellent performance; and I cannot but admire the author's magnanimity in altering his hypothesis, and making a public profession of his former error, in his last edition. In this, I think, he truly shews the great man. That envious creature, Dr. Middleton, who was always pecking at great men, and Dr. Mead amongst the rest, was never capable of any thing so noble as this.

1758, July.

IX. On Promoting the Growth of Trees.
MR. URBAN,

HAVING frequently observed that trees planted in a hard soil have been little bigger in their twentieth year, than others of the same kind, planted in a light soil, have been in their sixth, I conceived a desire that my countrymen should be informed of a successful method of treating such stinted trees, recommended by a man of great learning and ability in a neighbouring nation, and have accordingly sent you an extract of M. de Buffon's Memorial on the culture of forest trees, presented to the Royal Academy at Paris.

All soils may be reduced to two species; the clay, or hard, and the light, or sandy. In order to sow in a light soil, the ground must be ploughed; an operation which will be the more cheap and successful, in proportion as the soil is more light; and is the only labour necessary, for the acorns may be sowed by a person following the plough. And as these soils are generally dry and hot, the weeds, which the following spring produces, must not be plucked up, because they retain a moisture and coolness, and guard the young oaks from the too intense heat of the sun; and in the autumn, when the weeds wither, they serve as straw to shelter from the cold of winter, and prevent the tender fibres of the root from freezing. In sandy soils nothing more than this is requisite; for the roots of the young trees finding a soil light, VOL. II.

E e

and easily to be divided, spread without obstruction, and are nourished by all the juices and moisture furnished by the earth, rains, and dews, which quickly penetrate the loose texture of this ground.

But in an hard soil, a very different method must be pursued, and after all, success is more uncertain. A previous ploughing of this kind of ground is not only useless but detrimental: the best way of planting the acorns here is with a pricker, without any previous cultivation of the soil. The height gained by the young shoots the first year must be carefully remarked; and it must be also noted whether they have pushed out more vigorously the second than the first, and the third than the second year. While their growth continues to increase, or so long as it does not diminish, nothing must be done; but it will generally be perceived that, on the third year, the growth will be diminished, and if they are suffered to stand the 4th, 5th, and 6th, their growth each year will be still less and less: and whenever this happens, without having been caused by severe frosts, or other extraordinary accidents, the young tree should be cut down to the ground in the month of March, by which many years will be gained in the whole of its growth; for the young shoot, left to itself in a stiff and hard soil, has not strength to extend its roots, which, too strongly resisted, return on themselves: the efforts made by the small tender fibres, which are the proper canals of nourishment, are ineffectual; the tree, therefore, deprived of nourishment, languishes, and its progress is annually less; but if this tree is cut down, the whole force of the sap is exerted on the root; all the fibres are expanded, and piercing the soil with greater force than they are resisted, open for themselves new ways, and by this accession of strength, accumulate the nourishing vegetative juices so as to produce a shoot, in one year, more vigorous and tall, than that of three years growth before it was cut down.

In excessive hard and tough earths, after having cut away the young shoot at the end of two years, it has been found necessary to cut it down again at the end of four other years, upon observing it to languish; and this method has on trial succeeded so well as to prove experimentally, that cutting down young shoots at a proper tine is the best and only culture necessary to improve woodland in the highest degree yet known; and instead of hindering, it surprisingly accelerates the growth of trees, even so as to gain several years advantage of those that have not been cut.

- 1748, May.

X. Prolific Nature of some Vegetables.

Wandsworth, March 6, 1752. THERE are some instances of vegetation that are really amazing; nature seems in many cases to act lavishly; and yet, I believe, it is owing to our ignorance of her grand designs, when we think so. But to come to examples; Indian corn is so prolific, that it often produces two thousand grains from one. In the year 1732, one self-sown, or accidental oat-corn, in Mr. John Hope's garden, in this town of Wandsworth, produced six very large stems, and fourteen smaller; one of which measured, from the root to the top, full five feet; and the number of grains they produced, being carefully told, amounted to four thousand, eight hundred, and sixty four. The last edition of Camden's Britannia mentions corn being sown, in a field in Cornwall, after a great battle fought there in the civil war time, that brought forth four or five ears on every stalk. I find in Motte's Abridgement of the Philosophical Transactions, Vol. II. p. 290, that one M. de la Pryme having soaked three barley corns, and planted them about two feet' one from another, they had sixty-five, and sixty-seven stalks a-piece from their single grains, with an ear upon every one, which had about forty corns a-piece in them. But what Mr. Digby mentions (as we are told in the aforesaid Philosophical Transactions) is scarcely credible, because it so far exceeds all other experiments, or observations of that nature; that a plant of barley rising from one corn, which by steeping in saltpetre, dissolved in water, brought forth two hundred and forty nine stalks, and above eighteen thousand grains. In Eame's Abridgement of the Philosophical Transactions, part II. p. 343, we have the following account of a prodigious increase from a pompion seed. We are there told, that in the year 1699, a single pompion* seed was accidentally dropped in a pasture, in New England, where cattle had been foddered for some time; this single seed took root of itself, and had but one stalk, which measured eight inches round, and from it were gathered two hundred and sixty pompions, one with

*It is probable that this was that species of pompion, or gourd, that strikes out roots at the joints, which furnish a new supply of sap to carry on se wonderful a produce.

another as big as a half-peck. In the year 1739, my brother, John Massey, who then lived at Sutton, in the parish of Beckingham in Lincolnshire, had a turnip, which grew in his ground, that, when the top was cut off, weighed just twenty-two pounds; it was produced in land that had not been dug up, or ploughed before, in the memory of man. He had many other very large ones, in the same crop, which he had not the curiosity to weigh; and, notwithstanding they were so large, yet they were a soft, pleasant, and good eating kind of turnip. I think accounts and observations of this nature ought not to be made public for amusement only, or to satisfy an idle curiosity; but with a view to show what great care divine providence takes in preserving and propagating (and even sometimes wonderfully) every species of beings, animal and vegetative; so that it seems impossible that any of them should be entirely lost, notwithstanding the great destruction of some, and neglect of others. And also, that such accounts may be rendered some way serviceable to mankind, especially to the industrious farmer and gardener; who may be prompted, by such hints, to try compendious and saving, and consequently profitable, ways of raising plants and vegetables, by observing such instances as I have related, by soaking the seeds in some proper liquid, or adapting and preparing the ground properly.

Yours, &c.

W. MASSEY.

P. S. About ten years ago a seed of woad, supposed to be voided by a bird, shot up and branched like a little tree, upon the chalky bank by the side of the bowling-green at Dunstable; a vegetable not known there; each branch was as big as most of the single plants cultivated in Kent for the dyers.

1752, March.

XI. No Central Fire in the Earth.

MR. URBAN,

DR. Kirkpatrick concludes his reflections on the causes that may retard the putrefaction of dead bodies, with these words: The united experience and penetration of our whole spe cies is insufficient to inform us, when, and by what precise means, the element, that has lately so often, so extensively,

and in a very late instance, on the coast of the Adriatic, so destructively struggled towards our surface, shall at last triumph over every impediment; and, utterly effacing the arch, on which we sport with such confidence, &c.' By which he seems to insinuate there is a central fire, as many other naturalists before him have done; but no doubt a great number of your readers, Mr. Urban, as well as myself, would be glad to be informed by him, if he pleases, or any other gentleman of extensive knowledge, upon what foundation that notion rests. This earth, at the final consummation of all things, may doubtless be consumed without such an agent, by a comet for instar.ce; consequently that catastrophe does not necessarily imply the existence of a central fire. And though there may be much warmth, and even heat, in the bowels of the earth, and that at the bottom of the deepest mines, yet I apprehend that those may be generated otherwise, to wit, by the mixture and collision of certain heterogeneous bodies, as the chymists teach. This accidental spontaneous fire, in concurrence with other causes, will account for the origin and continuance of volcanoes, the phænomenon of earthquakes, so far as they are owing to this element, the formation of precious stones, minerals, hot baths, and the like natural appearances.

It is difficult to conceive how a fire, pent up in the centre of the earth, can possibly burn without spiracles, and yet we do not find any such. The volcanoes, which bid the fairest, are all in general in mountains, and do not run any considerable depth below the roots of their respective hills, though perhaps some little they may, since some as I think have been of opinion, though others controvert it, that Etna and Vesuvius communicate under the streights of Messina. But what is this to reaching down to the centre, or even communicating with that, when the semidiameter of the earth is not less than 3440 Italian miles?

If the volcanoes are not the spiracles of the central flame, we know of no other fissures that can pretend to it. Job Ludolphus tells us indeed, that in Ethiopia there are 'immense gulphs, and dreadful profundities; which, because the sight cannot fathom, fancy takes them for abysses, whose bottoms Tellezius will have to be the centre of the earth.' If they extend downwards, as far as the centre, we are sure there is no central fire; for there is no appearance of flame or smoke in these horrible hiatus's. But the truth is, the mountains of Æthiopia are most prodigious; the Alps and Pyreneans are nothing to them; they are many of them not declivious, but precipicious, like the cliffs at Dover;