and Lead, as it is it self a White _Calx_, so does it turn the _Pitta di
Crystallo_ (as the Glassmen call the matter of the Purer sort of Glass,
wherewith it is Colliquated into a White Mass, which if it be opacous
enough is employ'd, as we elsewhere declare, for White Amel. But of the
Colours which the other Metals may be made to produce in Colourless Glass,
and other Vitrifiable Bodies, that have native Colours of their own, I must
leave you to inform your self upon Tryal, or at least must forbear to do it
till another time, considering how many Annotations are to follow, upon
what has in this and the two former Experiments been said already.

_Annotation I._

When the Materials of Glass being melted with Calcin'd Tin, have compos'd a
Mass Undiaphanous and White, this White Amel is as it were the Basis of all
those fine Concretes that Goldsmiths and several Artificers imploy in the
curious Art of Enamelling. For this White and Fusible substance will
receive into it self, without spoyling them, the Colours of divers other
Mineral substances, which like it will indure the fire.

_Annotation II._

So that as by the present (XLVIII.) Experiment it appears, that divers
Minerals will impart to fusible Masses, Colours differing from their own;
so by the making and compounding of Amels, it may appear, that divers
Bodies will both retain their Colour in the fire, and impart the _same_ to
some others wherewith they were vitrifi'd, and in such Tryals as that
mention'd in the 17. Experiment, where I told you, that ev'n in Amels a
Blew and Yellow will compound a Green. 'Tis pretty to behold, not only that
some Colours are of so fix'd a Nature, as to be capable of mixture without
receiving any detriment by the fire, that do's so easily destroy or spoyl