Tin . 
401 
itself, add to it the quicksilver, and when the amalgam is 
cold reduce it to powder, and mix it with the sulphur and 
sal ammoniac, and sublime the 'whole in a glass matrass, 
standing in a sand-bath. Apply a gentle fire for some 
time, 3 or 4 hours, till the white fumes which arise co- 
piously at first, begin to abate, then raise the fire till the 
sand becomes red-hot, and keep it at this point, neither 
increasing nor diminishing it, for a considerable time, ac- 
cording to the quantity of the materials, till you judge the 
operation to be completed. The matrass being broken 
when cold, the mosaic gold is found at the bottom, and 
above it a sublimed substance, the composition of which 
will be presently mentioned. 
The mosaic gold therefore is not a sublimate , but is a 
fixed substance, and it cannot be raised by heat unchang- 
ed. It weighs considerably more than the tin employed, 
but the actual product is extremely uncertain. A good 
deal of care is required in managing the fire, for if too 
slack none of the mosaic gold will be formed, and if urg- 
ed beyond a moderate redness it is again decomposed 
into a dark sulphuret of tin, totally without lustre. The 
proportions of the ingredients are variously given. For- 
merly equal parts of all the substances were employed, but 
they may be reduced to the proportions here given with- 
out diminishing the product. 
As soon as the ingredients are mixed an odour of sul- 
phuretted hydrogen is given out, which increases rapidly 
as heat is applied ; and if the process be performed in a 
retort, with a receiver attached to it, a quantity of hydro- 
sulphuret of ammonia or volatile silver of sulphur, comes 
over, which condenses in the extremity of the receiver, 
partly as a liquid and partly in beautiful crystalline need- 
les. The sublimate which is formed above the aurum 
musivum, and which is much less volatile than the am- 
maniacal hydro- sulphuret, is an extremely compound 
