XXXVI. This is the substance of what, in support of this paradox, I have found in the Works of the before-quoted philosophers; to which I shall add a conjecture of my own, which appears to me very efficacious to render credible, the formal existence of particles of iron, or load-stone, in all vegetables whatever; whether they are of load-stone, or iron, makes very little difference, as all experimental philosophers are agreed, that load-stone is nothing else but a fat or rich vein of iron. XXXVII. My conjecture is founded on a theory, which is embraced at present by all the mathematicians, and confirmed by conclusive reasonings, which are founded on the earth being endued with a magnetic virtue. The truth of this theory, is proved by innumerable observations. It has been found, that the magnetic needle poised in equilibrio, accommodates itself to the meridian of the earth, in the same manner the load-stone does, that is, it does not point to the poles of the heavens, but to those of the earth; for it has been observed in the northern regions, that it does not appear to elevate or point towards the pole of the heavens, but rather seems to depress, or point down towards that of the earth; and generally, in all, and every particular, the magnetic needle has been found to be affected in the same proportions with respect to the terraqueous poles, that it is with respect to the load-stone. The various declinations that it is liable to, from the pole of the earth, in different places, cannot be attributed to any other cause, than that of the unequal magnetism, of the terraqueous globe in different regions; and the different declinations of the poles of the load-stone are attributed to the unequal magnetism or perfection of the parts of the stone. It has been found, that the earth itself, can communicate the magnetic virtue to iron; for if you take a bar of iron red-hot from the forge, and place it perpendicular in the earth, and there let it remain till it becomes cold, it will manifestly acquire the magnetic virtue; and if it is afterwards poised in equilibrio, it will point to the poles of the earth, in the same manner as if it had been touched by a load-stone. It will also acquire the same virtue, if it has remained for many years in a perpendicular position, without its having been placed so in the earth red-hot; and the same has been experienced with respect to bars, that have been set before windows in an upright position. The same effect will also be produced, by laying a hot bar upon the ground, exactly in a north and south direction, till it gets cold; but if it is so laid without being previously heated, and suffered to continue in that position for several years together, it will be found to be impregnated with the magnetic virtue. Whoever is desirous of seeing an account of these observations more at large, and to satisfy himself how they evince the magnetical quality of the earth, should read the mathematical authors