I 



ACTION OP PLATINA AND MERCURY. l^ 



feven or eight operations in the forge lo [)errorm daily, and I 

 do not exaggerate the number of attempts I made during this 

 time, as well in the dry as in the humid way, in ftating themi 

 to have been one thoufand. Amongft thefe I had four fut- 

 cefsful operations. I perfevered, becaufe even in my failures 

 I faw fufficient to convince me that I Ihould quit the road to 

 truth if I defifted. After all ray labour and fatigue I cannot 

 fay that I had come nearer to ray obje6l, of obtaining more 

 certainty in my procelfes. Their fuccefs was flill a hazard on 

 the dice, againft which there were many chances; but till 

 others had thrown as often as I had done, they had no iolid 

 right to deny the exiftence of fuch a combination. On this 

 foundation none, I believe, have eHablitbed fuch a right. 

 Mels. Rofe and Gehlen do not fay how often their experi- 

 ments were repeated ; but it is probable that if they had been 

 performed very often, thefe authors would not have negledted 

 to mention it. M. Richter ftates his merely as preparatory 

 to more extenfive refearches ; and M. Tromfdorlf, as well 

 as M. Klaproth, mention little more than the fadl. If the 

 German chemifts have concluded againft my refults, they have 

 done fo without juft grounds, and without having beftowed 

 upon them that labour and afliduity for which ihey are ufually 

 fo remarkable. 



In this ftafe of uncertainty the compound nature of palfa- M. RItterthe 

 dium received an indirect, but a verv able, fupnort from fome ^'^^^l^jy.^^'^' 



• ' ' has eftabliihed 



experiments of M. Ritter, the celebrated Galvanifl of Jena, the order of ^al- 

 M. Ritter had afcertained the rank which a greater number of ^'*".''^ relation ia 

 fubftances hold in a galvanic feries, arranged according to 

 ihe property they potPifs of becoming potitive or negative 

 when in contad with each other. He had eftabliihed the 

 following order, the preceding fubftance being in a ininus 

 relation to that which comes next. Zinc, lead, tin, iron, bif- 

 muth, cobalt, antimony, platina, gold, mercury, filver, coal, 

 galena, cryftallized tin ore, kupfer nickel, fulphur, pyrites, 

 copper pyrites, arfenical pyrites, graphite, cryftallized oxide 

 of manganefe. He had the goodnefs to try palladium in my He found pai 

 refence, and found it to be removed, not only from what I '^'"'" to be le- 



. . , /• moved in that 



elieved to be its conltituent parts, but altogether from among order from 



ithe metals, and to ftand between arfenical pyrites and graphite, among the me- 

 rr.i • /■ 1 I • -. r It • • I 1 • /■ tals to the com- 



inis relult led Mr. Ritter into a new and general train ot ^^^^ j^Q^jg,^ 

 feafoning, and induced him to undertake the examination of a 



great 



