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 those of other Bodies; but Mineral Pigments may be mingled by fire little less regularly and successfully, than in ordinary Dyeing Fatts, the vulgar Colours are wont to be mingled by the help of Water. _Annotation III._ 'Tis not only Metalline, but other Mineral Bodies, that may be imploy'd, to give Tinctures unto Glass (and 'tis worth noting how small a quantity of some Mineral substances, will Tinge a Comparatively vast proportion of Glass, and we have sometimes attempted to Colour Glass, ev'n with Pretious Stones, and had cause to think the Experiment not cast away. And 'tis known by them that have look'd into the Art of Glass, that the Artificers use to tinge their Glass Blew, with that Dark Mineral _Zaffora_, (some of my Tryals on which I elsewhere acquaint you) which some would have to be a Mineral Earth, others a Stone, and others neither the one, nor the other, but which is confessedly of a Dark, but not a Blew Colour, though it be not agreed of what particular Colour it is. 'Tis likewise though a familiar yet a remarkable practise among those that Deal in the making of Glass, to imploy (as some of themselves have inform'd me) what they call Manganess, and some Authors call _Magnesia_ (of which I make particular mention in another Treatise) to exhibit in Glass not only other Colours than its own, (which is so like in Darkness or blackishness to the Load stone, that 'tis given by Mineralists, for one of the Reasons of its Latine Name) but Colours differing from one another. For though they use it, (which is somewhat strange) to Clarifye their Glass, and free it from that Blewish Greenish Colour, which else it would too often be subject to, yet they also imploy it in certain proportions, to tinge their Glass both with a Red colour, and with a Purplish or Murry, and putting in a greater Quantity, they also make with it that deep obscure Glass which is wont to pass for Black, which agrees very well with, and may serve to confirm what we noted near the beginning of the 44th Experiment, of the seeming Blackness of those Bodies that are overcharg'd with the Corpuscles of such Colours, as Red, or Blew, or Green, &c. And as by several Metals and other Minerals we can give various Colours to Glass, so on the other side, by the differing