Mr. Smee on the Galvanic Properties of Metals. 315 
cases where organic matters are replaced by pyrites, but also 
in those where silica and other earthy substances are con- 
cerned. 
By this process I was easily enabled to cover the surface 
of any article moulded in plaster, sulphur, wax, or any other 
substance; but it usually happened that by the time that the 
whole surface was covered some parts had begun to throw up 
little mammillated excrescences of copper which destroyed 
the smoothness and regular appearance of the surface. Al- 
though I thus failed in my original purpose, yet I saw sufficient 
reason to feel no doubt that plaster may be covered with a 
uniform coating of copper. The surface of the copper preci- 
pitated against the plaster is of course smooth, and there- 
fore the process might be conveniently employed in any case 
where one or only a few copies are required of any metallic 
surface. Thus finger plates for doors, and all kinds of thin 
ornamental metal work, may be copied with great perfection. 
A very beautiful effect is produced by coating the sur- 
face of facsimiles of medals or casts, made of lead or fusible 
metal, with a thin film of reduced copper ; they then exhibit 
the beautiful silky dull appearance which I have before al- 
luded to as being possessed by the precipitated metal. If 
these could be preserved from tarnishing by the application 
of any varnish or lacquer, exceedingly beautiful and cheap 
ornaments might be made in this manner, such as clock 
cases, &c. 
I have likewise been engaged in a series of experiments on 
the precipitation of other metals by similar means, and shall 
probably, when sufficiently at leisure, prepare a short account 
of them. 
.38, Bedford Row, March 2 , 1840. 
LI II. On the Galvanic Properties of the Metallic Elementary 
Bodies, with a description of a new Chemico-Mechanical 
Battery, By Alfred Smee, Esq.* * 
T AST May a number of experiments were performed upon 
the galvanic properties of the non-metallic elementary 
bodies, and these were attended with the acquisition of some 
curious information f? but till lately no opportunity has pre- 
sented itself of extending the series of investigations then con- 
ducted: now, however, that I believe that I can lay before 
* Communicated by the Author. 
t The results connected with this part of the subject will be given in a 
future number. 
