cf the Pyrites, 75 



would feem to fuggeft an enquiry, whether their 

 tint be not owing to the lhare of metal they con- 

 tain. I know not, whether the amethyfl does not 

 hold gold •, as there is no experiment extant for 

 giving fuch a violet colour to a ftone, or ftony 

 glafs-rlux, except by the means of gold, with the 

 addition of tin-, efpecially, as I have a method of 

 imparting this colour laflingly to fpring-water, 

 without making it lefs fweet and potable, from 

 gold, without tin, or any other mineral, or me- 

 tallic body, barely by means of a certain fait. As 

 to the jafper blufh, I would mention iron, as, at 

 leaft, the earth of this metal eminently carries this 

 colour ; or even gold, either feparately, or jointly, 

 with the former, none of thefe circumflances being 

 inconfiftent with the nature of things. All this I 

 propofe as conjecture only -> for tho', indeed, nei- 

 ther gold, nor any other metal, is, by analyfis, or 

 refolution, educible from fuch amethyfts, quartz* 

 and drufe ; nay, is as little poffible, as that the 

 leaft trace of a metal mould be manifefled by the 

 quickeft, moll tender fcales, in artificial, varie- 

 gated fluxes and glafles, from the metal being 

 widely difperfed-, and to be educed from glafs, a 

 body the moil tender and retentive, and to be ex- 

 hibited in its metallic form : yet, fynthefis* or 

 compofition, gives fome countenance to the con- 

 jecture *, namely, as the well known gold-purple, 

 or the gold powder, made with tin, bears being 

 introduced as a violet colour into glafs, nay, into 

 a common water : this I the rather mention, feeing 

 in chemiftry, and according to the doctrine of na- 

 ture, the proofs from compofition are preferable 

 to thofe from refolution. But be this as it will, the 

 different ftrata in this jafper-flone manifeft fome- 

 thing different, if not in the ground-mixtions, yet 

 in the degrees of the coction and maturation of the 

 mixts i xhejtrata not being produced externally in 



couches* 



