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V I T R I O L U M.

< 2 . Vitriolum cceruleo-virens.

Blueijh-green Vitriol.

This is a more beautiful Fossil than the former, and of a much more pleasing co-lour, and is evidently prov’d by experiments, to be form’d of a mixt solution of theparticles of iron and copper in the acid of Sulphur, which, by the assistance of water,is form’d into a metalic Salt, no way differing from what may be produc’d by art,from a solution and crystalization of those metals in the fame menstruums.

It is a very pure substance, of a firm, compact; and even texture, and considerablyheavy; it is found of various sizes, but seldom very large, and is usually of a some-what rudely orbicular form, covered with multitudes of imperfect and mutilated rhom-boidal Crystals; it is sometimes also found coating over the sides of fissures of Stone,in crusts of an inch thick, and of considerable extent, and sometimes concreted roundssioots of the various Crystals and Spars: and in all these figures, tho’ its bottom sur-face where it adheres to the substance it coats over is smooth, and its general mass ofno regular figure, yet its outer surface always is covered with concretions, ap-proaching to Rhomboids; these are very smooth and polite, and the whole massesare moderately firm and hard, and break with an even and bright surface. Its co-lour is a blueifh-green, very exactly that of the Beryll, or Aqua marine Gem, andit is very bright and transparent.

It will not run per deliquium, but sometimes feels a little moist on the surface indamp weather.

It very freely dissolves in water, to which it gives its sea green colour, and is bya regular evaporation and crystalization, to be again procur’d from it, in form of some-what thick and short Rhomboidal Crystals.

In the fire it calcines first to a greyish white, and afterwards to a deep purple.

It is sometimes found in the mines of Goffelaer in Saxony, but more frequently inthose of Hungary and Transilvania, and is very common also, several of those onthe Hartz Forest.

3 . Vitriolum albescens.

White Vitriol,

This is in all respects, except figure, the fame substance with the white Vitriol of theshops, as that indeed is no other than this Salt dissolv’d, and again concreted; there beingin nature no other known white Vitriol; nor is it in the power of art to contrive anytolerable counterfeit for it. It owes its origin, like the rest, to iron and copper, dis-solv’d by the acid of Sulphur and water, and again concreted into this form • but itcontains some other substance beside these, possibly lead, possibly some other mineral,not of the class of the metals, to which it owes its colour, and mode of existence, andwhich art cannot add to the, composition, till it first knows what it is.

It has been vulgarly fuppos’d, that this was a preparation of the common green Vi-triol by fire, but experiment proves the contrary, and it is well known by all whohave seen the mines at Gosselaer, to be a native Fossil.

It is in its most perfect state a firm and compact substance, moderately hard, andconsiderably heavy, of no determinate ssiape or size, but found coating over the sidesof fissures of rocks, in small crusts, often roundish, but more usually of ragged andunequal edges, of a smooth surface, moderately hard, and in some degree pellucid insmall pieces. The great Geoffrey mentions pieces of it found there pellucid as Crystal,but I have not been able yet to procure any so fine ; and even what is here describ’d isa state it is very rarely found in. Its common appearance being in form of a downy efflo-rescence, which stands very thick on the walls of subterranean caverns, and the roofs ofhollows, made in working for ores; it is in this state of a light substance, and of a verylax texture, very readily mouldering to pieces between the fingers, and of a dusky,and sometimes brownish or yellowish white. In either of these states it very readilydissolves in water, and after evaporation is reduc’d to the large cakes, in which wereceive it in the shops.

It is produc’d in the mines at Gosselaer in Saxony, and those of Cremnitz in Hun-gary, and in the East Indies. These Vitriols have their several uses, and those very

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