BOLES.

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4 . Bolus floride lutea dura, quæ ’Terra Lemnia flava Ojficinarum .Hard, bright yellow Bole, calTdyellow Lemnian Earth.

This is a pure, genuine and very valuable Earth, common in the shops in other na-tions, and sometimes is seen among us.

It is a pure and very fine Bole, of a bright, lively and florid yellow, not at all re-sembling that of any of the other yellow Boles, but rather approaching to that of thebrighter yellow Ochres ; it is of close, compact, dense texture, very heavy, and of a smoothglolly surface ; ’tis of much the fame hardness with the true yellow Bole Armenick.It does not break without difficulty between the fingers ; and tiro’ of so florid a colour,never stains the hands; it readily melts in the mouth without the least grittyness,and if apply’d to the tongue, adheres firmly to it.

The Microscope shews it to be of a pure, even, and regular texture.

It makes no effervescence with Aqua Fortis, and in the fire acquires a considerablehardness, and dusky colour. Urg’d by a very violent one, it becomes a very white butcoarse glass.'

It is dug in the island of Lemnos, and constitutes the stratum over the red Lem-nian Earth, to be described hereafter, but in some places between the two there is a thinstratum of an Earth, of a middle nature and mixt colour between both.

It is a Sudorific, Astringent and Vulnerary, but is very frequently counterfeited wherein use ; the more common sophistications of it are of two kinds, the one made of ayellow Ochre, which is easily discoverable, by its staining the hands ; and the other ofa dense yellow clay, which may be known by its weight and dusky colour; for tho’the genuine is very heavy for a Bole, yet this counterfeit is ever much more so : thecolour of the native Earth is also not easily come up to.

5 . Bolus aurea friabilis, quæ Terra Eignicenfs lutea authorum.

Gold coloured friable Bole.

This is the Terra Lignicenfis Sigillata lutea. Charlt. 225. Muf. Calc. 114.

It is an impure Earth, of a bright and strong yellow; or as Charlton very pro-perly expresses it, a gold colour, but is of a loose and more crumbly texture than mostof the other Boles. It is moderately heavy, of a smooth glosty surface, easily brokenbetween the fingers, and not staining the hands. It is readily diffusible in water, andmelts easily in the mouth, but always leaves some little grittyness between the teeth.

The Microscope shews it to be of a cavernous, loose, irregular texture. ■

It makes no effervescence with acids.

In the fire it acquires a little additional hardness, and a pale brown colour; and urg’dby a violent one, it affords a spungy, dusky blue glass.

It is dug in many parts of Germany, particularly about Emeric, in the circle ofWestphalia; and is frequently used in Cordial and Astringent electuaries. It is oftenmade a Succedaneum for the yellow Silesian Bole, of which they are very fond, norindeed are they much less so of this.

6 . Bolus luteo fufca, quæ Terra fgillata Silefaca authorum.

Brownish yellow Bole.

This is the Terra Silesiaca Sigillata quæ Chymicis Axungia Solis dicitur. Charlt.Foff. 6. Terra Sigillata Silesiaca Worm. 2. Hoffm. 664. Terra Sigillata Sileiiana.Imper. 128. Bolus Silesian. Muf. Calc. no,

It is a pure Bole, considerably heavy, of a moderately compact texture, and of adead brownish yellow colour ; it is easily broken between the fingers, does not at allstain the hands, and has a smooth surface, but less glofly than many other of theBoles. It is readily diffusible in water, melts easily In the mouth, and leaves no grit-tyness between the teeth.

The Microscope strews it to be of an equal texture, and regularly laminated, or com-pos’d of a number of thin plates, laid close on one another, which are in reality somany very thin strata.

It makes no effervescence with Aqua Fortis.

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