a stone capable of producing mushrooms.

In the Ephemerides of the Curious we find mention made of a stone, so called by Dr John George Wolckamers, who saw one in Italy, which never ceases to produce in a few days mushrooms of an excellent flavour by the most simple and easy process imaginable. "It is (says he) of the bigness of an ox's head, rough and uneven on its surface, and on which also are perceived some clefts and crevices. It is black in some parts, and in others of a lighter and greyish colour. Internally it is porous, and nearly of the nature of the pumice-stone, but much heavier; and it contains a small piece of flint, which is so incorporated with it as to appear to have been formed at the same time the stone itself received its form. This gives room to judge, that these stones have been produced by a fat and viscid juice, which has the property of indurating whatever matter it filtrates into. The stone here spoken of, when it has been lightly covered with earth, and sprinkled with warm water, produces mushrooms of an exquisite flavour, which are usually round, sometimes oval, and whose borders, by their inflexions and different curvatures, represent in some measure human ears. The principal colour of these mushrooms is sometimes yellowish, and sometimes of a bright purple; but they are always distinguished with different spots, of a deep orange colour, or red brown; and when these spots are recent, and still in full bloom, they produce a very agreeable effect to the sight. But what appears admirable is, that the part of the stalk which remains adhering to the stone, when the mushroom has been separated from it, grows gradually hard, and petrifies in time, so that it seems that this fungites restores to the stone the nutritive juice it received from it, and that it thus contributes to its increase." Joha Baptist Porta pretends, that this stone is found in several parts of Italy; and that it is not only to be met with at Naples, taken out of mount Vesuvius, but also on mount Pantherico, in the principality of Arellino; on mount Garganus, in Apulia; and on the summit of some other very high mountains. He adds, that the mushrooms which grow on those sorts of stones, and are usually called fungi lyncuri, have the property of dissolving and breaking the stone of the kidneys and bladder; and that, for this purpose, nothing more is required than to dry them in the shade, and being reduced to powder, to make the patient, fasting, take a sufficient quantity of this powder in a glass of white wine, which will cleanse the excretory ducts of the urine, that no stones will ever after be collected in them. As to the form of these mushrooms, their root is stony, uneven, divided according to its longitudinal direction, and composed of fibres as fine as hairs, interwoven one with another. Their form, on first shooting out, resembles a small bladder, scarce then larger than the bud of a vine; and if in this state they are squeezed between the fingers, an aqueous subacid liquor issues out. When they are at their full growth, their pedicle is of a finger's length, larger at top than at bottom, and becomes insensibly slenderer in proportion as it is nearer the earth. These mushrooms are also formed in an umbrella, and variegated with an infinity of little specks situated very near one another. They are smooth and even on the upper part, but underneath leafy like the common mushrooms. Their taste is likewise very agreeable, and the sick are not debarred eating of them when they have been dressed in a proper manner. Curiosity having prompted some naturalists and physicians to submit these stones to a chemical analysis, in order to be more competent judges of the uses they might be put to in medicine, there first came forth, by distillation, an insipid water, and afterwards a spirituous liquor. The retort having been heated to a certain point, there arose an oil, which had nearly the smell and taste of that of guaiacum; and a very acid salt was extracted from the ashes.