ii3 
PJatina and Mercury upon each othet . 
performed very often, these authors would not have neglected 
to mention it. M. Richter states his merely as preparatory 
to more extensive researches; and M. Tromsdorff, as well as 
M. Klaproth, mention little more than the fact. If the German 
chemists have concluded against my results, they have done 
so without just grounds, and without having bestowed upon 
them that labour and assiduity for which they are usually so 
remarkable. - 
In this state of uncertainty the compound nature of palla- 
dium received an indirect, but a very able, support from some 
experiments of M. Ritter, the celebrated Galvanist of Jena. 
M. Ritter had ascertained the rank w r hich a great number of 
substances hold in a Galvanic series, arranged according to 
the property they possess of becoming positive or negative 
when in contact with each other. He had established the 
following order, the preceding substance being in a minus 
relation to that w r hich comes next. Zinc, lead, tin, iron, bis- 
muth, cobalt, antimony, platina, gold, mercury, silver, coal, 
galena, crystallized tin ore, kupfer nickel, sulphur pyrites, 
copper pyrites, arsenical pyrites, graphite, crystallized oxide 
of manganese. He had the goodness to try palladium in my 
presence, and found it to be removed, not only from what I 
believed to be its constituent parts, but altogether from among 
the metals, and to stand between arsenical pyrites and graphite. 
This result led M. Ritter into a new and general train of 
reasoning, and induced him to undertake the examination of a 
great number of alloys, and of a variety of amalgams. He 
considered the subject as a philosopher; and his operations 
were those of a consummate experimentalist. It would be 
doing him an injustice to attempt an extract of his ingenious 
mdcccv, Q 
