108 J. Nickles on the Permeability of Metals by Mercury. 
of the connecting pieces became brittle, and had on breaking, a 
white color. It was obviously no longer copper, but an amalgam 
of this metal. 
This fact had too important a bearing on the amalgamation of 
zinc, which occupied me at that time, to be allowed to pass with- 
out examination. ‘The experiments which I made on this sub- 
ject, led to the general conclusion, that the metals which absorb 
mercury are permeable by it, and communicate this property to 
the alloys which contain a certain proportion of permeable metal. 
The metals on which I have operated are zinc, iron, cadmium, 
tin, copper, lead, antimony, silver, gold, and platinum. The 
manner of experimenting was suggested by the fact which had led 
to the researches. With a stylet I traced a line or furrow on the 
plate under experiment, and placed a little mercury in this fur 
row. In order to hasten the amalgamation, I introduced, before 
the mercury, a drop of bichlorid of mercury, acidified with hy- 
drochloric acid. By this means, the amalgamation takes place 
instantly, and the surface is fitted to retain at once the quantity 
of mercury necessary for the effect I would produce. 
A plate of zinc, a millimeter thick, is immediately attacked, 
and at the end of a minute, it is cut in two in the direction of 
the furrow. A thicker plate requires more time, and a deeper 
scratch on its surface; with a thickness of six millimeters, the 
plate took ten minutes and a little effort to break it: but in all 
cases the fracture was neat, and in the direction of the scratch oF 
furrow. 
After zinc comes cadmium and tin, then lead, silver, gold, and 
finally copper. All of these metals become amalgamated: the 
mercury infiltrates after a time more or less long, and renders them 
brittle. No permeability has been detected in iron, antimony an 
platinum, and these metals make no amalgam. Daniell has found 
a bar of platinum free from mercury, that had been for six yeats 
im contact with it; and to this time no amalgam of iron has beet 
re ® : 
; ‘There exists, it is true, an amalgam of antimony, but, accord- 
ing to Wallerius, when this amalgam, of a pasty consistence, 
triturated in the air, or when agitated with water, it loses its 
timony in the form of a black powder.* 
_ As to the action of mercury on metals, this fact at least is estab- 
lished : resistance of some to amalgamation, and the easy 
amalgamation of others. We have also shown that the perme’ 
bility takes the same direction; and we may conclude therefore 
that the alloys will participate in these qualities in the order # 
their composition. In fact, a plate of bronze, five millimeters 
te gees ahs ae 
* T should recall, in this connection, that mercury also is reduced to a black poW 
der by agitation in the air, 
