160 
MR. DAVY ON A SIMPLE ELECTRO-CHEMICAL METHOD 
In another experiment, a small quantity of arsenious acid, in powder, was 
mixed with hot tea. Some hours after it had cooled, it was filtered, and on 
being treated as in the preceding experiment, the arsenic appeared in a similar 
manner. Coffee, on being exposed to like treatment, afforded analogous results. 
I mixed five grains of pulverized arsenious acid in a small basin of warm 
and rather thick pea-soup, having fragments of the fibrous part of beef dif- 
fused through it. The platina spoonful of it was boiled nearly to dryness, 
several drops of muriatic acid were added, and by agitation most of the solid 
matter was dissolved, forming a thickish fluid. The zinc being applied, a white 
coaguluin changing to brown appeared, and the arsenic soon covered the sur- 
face of the spoon. Similar results were obtained when giblet soup was treated 
in like manner. 
Corrosive sublimate . — A few drops of a solution of corrosive sublimate in 
water, were well mixed with a solution of gelatine (isinglass) : a drop or two of 
the mixed fluids being placed on the platina spatula, and the zinc applied, the 
mercury presently precipitated; and this effect was more readily produced 
when a little diluted muriatic acid was previously added to the mixture. When 
a solution of nutgalls was added to the mixed gelatine and corrosive subli- 
mate, also when corrosive sublimate was added to yolk of egg, the results, by 
similar treatment, were precisely analogous. 
A small quantity of solution of corrosive sublimate was put into fluid albu- 
men (white of egg). To some of the precipitate in a platina crucible, a little 
diluted muriatic acid was added, and the zinc applied ; the albumen coagu- 
lated, and in about a minute some mercury was reduced in the crucible, and by 
continuing the experiment for a few minutes the quantity increased consider- 
ably. A similar experiment being repeated in a platina gilt crucible, in a short 
time the gold partially assumed a dark blueish grey colour. The mercury from 
both experiments was collected by sublimation on glass, as detailed before. 
When solution of corrosive sublimate was mixed with flour into a soft paste, 
put into the platina crucible, and diluted muriatic acid added, in the course 
of a few minutes after the zinc was applied, similar results as in the foregoing 
instances, were obtained. 
Corrosive sublimate in powder was mixed with butter, and diluted muriatic 
acid was incorporated with the mixture ; a little of the same being placed on 
