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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 shew what great care divine providence takes in preserving and propa gating (and even sometimes wonderfully) every species of production, 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 instance; 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 even 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 chemists teach. This accidental spontaneous fire, in concurrence with other causes, will account for the origin and continuance of volcanoes, the phenomenon 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 possible 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 Ætna 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 centres 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 Pyrenées are nothing to them; they are many of them not declivious, but precipicious, like the cliffs at Dover;

and therefore, supposing an interstice or valley between any two such monstrous precipices as these, the effect to an eye at the top must needs be most frightful and ghastly; and yet it may be justly questioned, could the trial be made, whether it would range any lower than the low-water mark of the great Ethiopic or Indian ocean. There is a perpendicular opening in the peak of Derbyshire, called Elden Hole, which Mr. Cotton plumbed to the depth of 884 yards, and the lead still drew; but he could never get the plummet so low afterwards*: but, take it at the greatest depth, they who are acquainted with the surface of the earth in those parts, will hardly think the bottom of this pit sinks beneath the edge of St. George's channel, on the coast of Lancashire. But these hideous chasms, as was observed, be they never so deep, afford no flames, no smoke, and therefore cannot be spiracles to an abyss of fire: and as there are no vents on the dry land, there can be none in those parts of the terraqueous globe which are covered with water: for the fluid would necessarily run in and extinguish the fire. Whereupon one cannot help remarking, that it is much more probable there should be an abyss of water at the centre, to which the scriptures give so much countenance, or a Terrella with Dr. Halley, than a globe of fire; for if any chinks were left at the formation of the earth originally, or have since happened by earthquakes, or any other means, the water, (and we know that the superfices of the earth is every where so far as we poor mortals have penetrated, replete with water) would of course rush in and lodge there.

But what, have the miners nothing to say? Truly, very little to the present purpose. Heats and damps have been accounted for above, and the mines universally, throughout the whole face of the globe, are in mountains, it being a maxim among these gentry that they are never to be sought for in plain champaign countries. Admitting then a shaft should sink 200 fathom, it would not pass beneath the highwater mark; but the question ought to be put, how far the mine has gone below the medium of low and high water, and supposing the excrescences on the surface of the earth were all pared off in order to make a smooth and even terraqueous sphere, no mines, I am persuaded, except perhaps some tin-mines near the shore in Cornwall, have even run deeper than that term. The plummet, I believe, has gone

In the additions to Camden, col. 595, it is said to have been plumbed 800 fathoms, but that is a mistake.

further towards the centre, than any thing in the world besides, and yet we are told that the sea is no where above a German mile deep, which is almost nothing in comparison with the semidiameter of the earth as specified above. But how are matters circumstanced in the great deeps? not at all favourably for the hypothesis of a central fire; there are no plants, nor any fish, those regions being too cold, as say the philosophers, for the spawn of fish to quicken there.

But perhaps authority swayed most, and the moderns founded their notion on the ancient Tartarus. This I fear is a misapprehension, for Hesiod places it under and not in the middle of the earth, and accordingly our Milton has judiciously seated it far without this terraqueous globe.

These observations, Mr. Urban, are very superficial, and are only thrown out in order to induce some able hand to give this question, which certainly merits it, a thorough discussion, and it would give me great pleasure, as I dare say it would you, to see it undertaken by some adequate

pen.

I am, Sir,

Your most obedient,

1753, Feb.

PAUL GEMSEGE.

XII. History and Culture of Cochineal.

COCHINEAL is greatly esteemed throughout Europe for the richness and excellence of its die; it has hitherto been produced only in the Spanish West Indies, but our newspapers tell us, that an attempt is now making to produce it in Spain, and as the nature and origin of it are not very generally known, it is hoped the following particular and authentic account of it will not be unacceptable to the public.

Yours,

AN.

It was not long ago believed that Cochineal was the seed of a plant; an opinion which probably took its rise from the circumstances of its being found upon, and gathered from, the leaves of a West Indian shrub: but certain it is that Cochineal belongs to the animal, and not to the vegetable,

*Hesiod. @yov. 720, 721, et M. L. Clerc ad. v. 728.

kingdom. The grains of Cochineal are each of them a little animal, which, when alive, greatly resembles a wood-louse, and from this resemblance it takes its name; for the Spaniards who first brought it into Europe and gave it its name, call a a wood-louse, Cochinilla. These animals do not indeed roll themselves up, on being touched, as the wood-lice do, nor are the largest of them bigger than a sheep-tick.

The plant, or shrub, whereon these little animals are bred, nourished, and brought to perfection, is called, in the West Indies, Nopal, or Nopalera, and is a sort of fig-tree. It is indeed rather a reap of leaves than a shrub. After the trunk or stem has risen a little above the ground, it divides itself into several arms or branches, and the trunk itself and its several ramifications are full of knots: each of these knots sends out a leaf, and from the end of that leaf springs another, and so on till the plant arrives at its full growth. Those leaves which spring first and are nearest the trunk or branches, are the largest: the leaves are pretty long and not flat, but somewhat rounded, or convex, and full of little portuberances, and covered with a thin and delicate membrane which always preserves a lively green colour. Its flower is small, and like a flesh-coloured ball, in the centre of which appears the fig; and as the fig increases, the flower decays and loses its colour, till at last it falls and leaves the fig alone. When the fig is ripe, its outer skin, or husk, is white, but its pulp or substance is of a deep red: it is very wholesome and pleasant to the taste, but it tinges the urine of those that eat it, and makes it look like blood, a circumstance which has often given great uneasiness to those who were ignorant of this property of the fruit.

The nopal is propagated thus: a number of holes are made in a line, about half a yard deep, and about two yards distant from each other: in every hole is put one or two leaves of the nopal weil spread and stretched out, and then covered up with earth, and from each hole there springs a new plant. The grounds in which it is cultivated ought to be well weeded and kept clear of all other herbs whatever; for they deprive it of its due nourishment. The plants should be pruned soon after the Cochineal is gathered, and all superfluous leaves cut away: they will put out fresh leaves the following year, and by these means will become more strong and vigorous. But it is to be observed that the Cochinillas which feed upon young plants, are larger and of a better quality than those which are gathered from plants which have stood some years.

The Cochinillas live upon the leaves of the nopal, and are

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