of a metallic Substance called Palladium . 311 
that such an affinity may not exist among metals. We have 
been forced to acknowledge it, in a few cases, among the earths ; 
and, from the profound and sagacious researches of Mr. Ber- 
thollet, we have learned many new facts, that promise us a 
rapid increase of knowledge. I shall beg leave to add a few 
examples, which are taken from that class of bodies to which the 
subject of the present Paper belongs, and show that the metals 
obey the general law of mutual attraction. 
EXPERIMENTS TO PROVE AFFINITY AMONG THE METALS. 
Exper. 1. I dissolved one hundred grains of silver in nitric 
acid, and precipitated by neutral muriate of platina. The preci- 
pitate, well washed and dried, was of a bright straw-colour, and 
weighed 147 grs. Reduced in a charcoal crucible, it yielded a 
button weighing 121 grs. and of the specific gravity of 1 1,6. The 
difference of weight, between the original hundred grains of silver 
and the 121, was owing to 21 grains of platina, which had been 
drawn down in precipitation along with the silver, by an affi- 
nity for that metal. This alloy is acted upon by nitric acid, and 
a great part of the platina is dissolved along with the silver; 
nor is it very easy to separate them by the common methods. 
Exper. 2. I dissolved one hundred grains of silver in nitric 
acid, and added about 1200 of mercury. I poured the mixed 
solution into a solution of green sulphate of iron, and obtained 
a very copious precipitate. When washed and dried, it weighed 
939, and was a perfect amalgam, in the due proportion of mutual 
saturation. Its specific gravity was 13,2 ; but no mercury re- 
mained with it after exposure to heat. 
Exper. 3. I dissolved one hundred grains of gold in nitro- 
muriatic acid, and added to it about 1200 grains of mercury. 
S s 2 
