162 
MR. DAVY ON A SIMPLE ELECTRO-CHEMICAL METHOD 
When a solution of corrosive sublimate (in small quantity) was added to 
some sherry or port wine in a platina crucible, and the zinc applied, a beau- 
tiful effect gradually took place. In the course of about a quarter of an hour, 
calomel was formed, and deposited at the bottom of the crucible in successive 
circles, which extended beyond each other, and differed slightly in their shades 
of colour, being alternately lighter and darker. The zinc became brittle at its 
point of contact, from amalgamation. These experiments were repeated in the 
platina gilt crucible with similar results, part of the gold was whitened, and 
calomel and mercury were afterwards sublimed from both crucibles. 
With raspberry vinegar and solution of corrosive sublimate, the results ap- 
peared to be similar to those produced with the wines. 
Sugar of lead, acetate of lead . — A solution of sugar of lead, in small quan- 
tity, was separately mixed with flour into a thin paste, with saliva, port and 
sherry wines, raspberry vinegar, and yolk of egg. A little of each mixture 
was put on the platina spatula, and the zinc applied, when the lead was soon 
reduced on the platina. 
A little of the solid compound of albumen (white of egg) and sugar of lead 
was placed on the spatula, and mixed with a drop or two of diluted aquafortis; 
the zinc being applied, the lead was reduced to a dark grey colour ; by gently 
rubbing it with the finger the lustre of the metal became apparent. The re- 
sults were analogous when sugar of lead was mixed with sheep’s blood and ox 
bile, and exposed to similar treatment. 
A mixture of gelatine (isinglass) and sugar of lead was put on the spatula, 
and the zinc applied ; the lead was slowly reduced : the effect was more rapid 
when a drop of diluted aquafortis or muriatic acid was previously added. The 
results were precisely similar when a solution of nutgalls was added to the 
mixed solutions of gelatine and sugar of lead. The yellow soft solid readily 
yielded metallic lead on platina by means of zinc. 
A small quantity of sugar of lead was put into some tea sweetened with 
sugar and cream ; some of the yellow matter produced being put on the spa- 
tula, and the zinc applied, the lead was slowly deposited. The results were 
similar when sugar of lead was mixed with milk and with coffee. The addi- 
tion of a little diluted aquafortis appears, in a number of cases, more readily to 
