428 PHILOSOPHICAL TRANSACTIONS. [aNNO I678. 



original alloy mixed with it, and not from any remainder of antimony, as ap- 

 peared by the inconsiderable waste upon melting it in a great heat with a blast 

 upon it: and also by the toughness and malleability : and by comparing it on 

 the touchstone, with sovereign gold allayed with silver, to which it agreed, but 

 w^as somewhat paler; holding, as judged, about a fourth part of silver, as the 

 sovereign gold holds a sixth. Neither was it quite free from copper ; because, 

 upon annealing, it always turned black on the surface. 



But for more exact discovery, itwas first refined with lead on a cupel, for sepa- 

 ration of any copper that might be in it. On which operation it came forth 

 334 grains; which was 24- grains less than it was before. Afterwards this last 

 was melted with between 2 and 3 parts of silver, and so wrought in aquafortis 

 for separation of the silver : and there remained in gold 28^ grains, being 5 

 grains short of the former. And yet it appeared, on the touch, not fine, but 

 paler than fine gold, and deeper than crown gold allayed with silver. So that 

 what remained in it was necessarily of silver ; and it might be estimated about 

 23 carats fine ; or to hold in fine gold about 27 grains. 



The loss of gold, on this refining with antimony, may easily be computed. 

 First, tV is to be deducted from the first quantity of crown gold, being 

 178 grains, for alloy; which is 14-^ grains. So the remainder is l63-|- grains. 

 Then the several parcels of fine gold, recovered and separated from the regulus 

 of antimony and gold, and also from the parcels of the crude antimony reduced 

 to regulus, are to be added together : that is to say, 30 grains, 63 grains, 27 

 grains, and 27 grains (the 27 grains last mentioned;) all which amount to 147 

 grains. Which being deducted from the first quantity of 163 grains, the dif- 

 ference is if) grains, which is ^ and -j-V of -^. 



The piece of regulus weighing 124 grains, melted with the second parcel of 

 antimony (in proportion to the former piece broke off, weighing 38 grains, and 

 upon refining yielded 30 grains of pure gold) must contain 98 grains of the 

 like gold ; and so much this second parcel of antimony must be charged with. 

 Toward which, the regulus weighing 74 grains, being refined, produced 03 

 grains. And that gold separated from the same antimony, being 27 grains, 

 added to the former, make 90 grains : short of the first quantity charged on 

 this parcel of antimony, by 8 grains. 



Some loss of gold may happen on powdering the regulus in an iron mortar, 

 as also by the papers necessarily used. But it is most probable, that the greatest 

 loss was by small sparks, which continually fiy up while the antimony is in a 

 boiling heat with the gold; which is always given it for the better melting and 

 mixture. These sparks appear heavy, by their rising not very high, and most 

 of them falling down again on the metal and within the pot : but many fly 



