XXXIII. And although the first time he made this experiment, he obtained only the rude lineaments of a tree, by varying afterwards the quantity of the oil of tartar, till he hit upon the just proportion of it, he obtained a perfect metallic vegetation, and produced a tree completely formed, with its roots, trunks, branches, leaves, and flowers. This able chymist concluded from his various observations on this matter, that both the volatility, and the vegetation, were owing to the filings of the iron; for without them, he could only produce some crystalline lumps at the bottom of the vessel, which he concluded proceeded from the nitre that had been dissolved. Whoever is desirous of knowing more of the manner and effects of these operations, may read the accounts of them in the Journals of the Academy Royal, of November 1706. XXXIV. But we are not to conclude from hence, that metallic vegetation is only to be produced by iron. The Abbé Vallemont in his first volume, _on the natural Curiosities and Art of Agriculture_, says, that there were exhibited at Paris, such like artificial metallic vegetations, produced from gold, silver, iron, and copper. But that which was the most common, and the most in vogue there, was the vegetation procured from silver, which the chymists called the _Tree of Diana_; and which was produced in the following manner. Dissolve an ounce of silver, in two or three ounces of spirit of nitre. Evaporate this dissolution in a sand-heat; till nearly half of it is consumed. Mix the remainder in a vessel, properly proportioned and suited for the business, with twenty ounces of clear water, and two ounces of quick-silver. By leaving this mixture afterwards in a state of rest for forty days, a silver tree will grow, and in that space of time will be compleatly formed, very nearly resembling a natural one, in shape and figure. Mons. Homberg, a celebrated chymist of the Academy Royal, by making use of the same materials, contrived to form a metallic tree in less than a quarter of an hour; the receipt for doing which, together with the physical explanation of this phenomenon, given by Mons. Homberg, may be seen in the Memoirs of the Academy Royal, of the thirteenth of November 1692. XXXV. These metallic vegetations, joined to the discovery beforementioned, of our having found iron in the ashes of all sorts of plants, not only prove that metals may, by virtue of certain fermentations, be made sufficiently volatile to enable them to rise upwards, and pervade all the tubes through which the alimentary juices of plants circulate, but also make it probable, that to this metallic mixture, they in great measure owe their vegetation.