REPORT ON GILDING, ETC. 
63 
method, which bears no comparison, in this respect, with 
the very imperfect processes of gilding on iron and steel. 
Only, as iron has little affinity for gold, the process is 
commenced by putting on the iron or steel a cupreous pel- 
licle, which favors the adherence of the gold, and fulfils the 
office of what is called in dyeing, a mordant. Desert knives, 
surgical instruments, arms, and laboratory utensils may re- 
ceive this layer of gold with economy and facility. 
Silvering. — All that we have said with regard to the 
applications of gold, applies with equal force to those of sil- 
ver. M. De Ruolz has likewise been able, by means of 
silver dissolved in cyanuret of potassium, to apply it with 
the greatest ease. 
Silver may be applied to gold and platinum, and also to 
brass, bronze and copper, in such a manner as to substitute 
plating. Tin, iron and steel are also easily silvered; for 
the use of chemists, we have proved that a capsule of brass 
silvered over, may answer the purpose of a silver one, to 
the extent of resisting the fusion of hydrate of potassa. It 
will not be uninteresting to look forward to the application 
of these new processes to the preservation of balances, phy- 
sical instruments, household utensils, those employed by 
confectioners and druggists, in the preparation of food or 
medicine containing acid, if iron or cast iron be required. 
These metals, fashioned into covers, (dish-covers?) and 
covered with a layer of silver, will favor the popular use 
in France, on account of their cheapness, of objects already 
common in England. Many covers of silvered iron are 
already made, by other more expensive and much less per- 
fect processes, at Birmingham, and are in common use in 
many families in England. 
Platinising. — By making use of the double chloride of 
platinum and potassium, dissolved in caustic potassa, a liquor 
is obtained which allows of platinising with the same facility 
and promptitude as in gilding or silvering. 
Chemists will find, in this process, a means of procuring 
