So Mr . Hatchett's Experiments on the various Alloys, 
with 19 grains of copper, 19 grains of fine iron wire were added, 
and the mixture was treated as before. 
The colour of this metal was pale grayish yellow ; it was 
perfectly ductile, and was rolled and stamped, without being 
previously annealed. 
By these experiments it appears, that gold made standard by 
wrought and cast iron, and even by cast-steel, is not brittle, 
as has generally been asserted ; for, although gold undoubtedly 
is thus rendered harder, it nevertheless does not become brittle, 
but remains so ductile, that it may be hammered, rolled, and 
stamped, without requiring to be annealed ; and, allowing that 
the change of colour produced by iron upon gold renders it 
unfit for coin, yet this mixture may probably be employed with 
advantage in ornamental and other works.* 
Emery is enumerated by mineralogists among the ores of 
iron ; and many very intelligent assayers, and others, even at this 
time, believe it to be a frequent - cause of the brittleness of gold. 
Some eminent metallurgists, such as Schlutter, support the 
same opinion, and have recommended certain processes to be 
employed to refine the gold, when thus adulterated. -f It must 
however be allowed, that it is not easy to conceive how such a 
combination can take place; for if (as is generally believed) 
emery consists of oxide of iron and siliceous earth, such a sub- 
stance cannot unite with gold in the metallic state ; and, even 
supposing that the ferruginous ingredient could in any manner 
be combined with gold, yet it has been fully proved, in another 
* It is said that this mixture is sometimes employed by goldsmiths. 
f Schlutter, Docimasie, p. 282. 
