PK.ETENDED NEW METAL; PALLADIUM. 5*7 



dlftlngullhes the latter fabftance from platina, is its denfity. 

 It is not iinufual to obtain it of a fpecific gravity folow as 13 ; 

 very frequently 15 or 17. In the firft experiments, I fufpe6l- 

 ed this h'ghtnefs to be owing to fome air-bubbles ; but repeated 

 fufion, and comparative experiments upon platina, foon con- 

 vinced me of the contrary. The augmentation of weight alfo, 

 which the platina never fails of acquiring, proves that this 

 metal has combined with fome ponderable fubftance ; and, in 

 fad, the refult of thefe operations is, an alloy which is a mean 

 betwixt platina in its pure ftate and what ha§ been called pal- 

 ladium. It is, confequently, fubjefl to infinite variation. 

 The firft efFefts which mercury produces upon platina are, to Mercury firft 

 render it more fufible, and to diminifti its fpecific gravity. J^ort fuf»ble"a^ii(l 

 The next new property conferred upon it is, the power of lighter j then 

 uniting with fulphur ; and, laftly, it becomes foluble in nitric ^^JJ^^^ngJJjg 

 a:cid. It is not however till the fpecific gravity is below 12, with fulphur; 

 or 1 2,5 at raoft, that it has acquired this property ; and afl thefe and ihll more 



rr rs r „ . ,- ^ i r ^ ' r C ■ , ^cndcrS it foluble 



etiects follow the diredl order ot the increale ot weight i^ nitric acid, 

 obfervable in the platina. vi<. under the 



It is not very difficult to combine a fraall quantity of mercury ,^"' ^ ^"^* ^ 

 with platina ; but, to refolve the problem completely, and to The author of 

 produce an alloy of thefe metals which fhall be of fo low a babw '^a? fo^'g 

 fpecific gravity as 11,3, and fball be foluble in nitric acid, is fteady method of 

 hot fo eafily accompli thed. From the repeated failures which ^o^^pofing it. 

 I have experienced in thefe operations, I am much inclined to 

 think that the author of palladium has fome method of forming 

 it, lefs fubjedt to error than any I have mentioned. No doubt 

 that perfeverance would put us in pofleffion of his fecret ; 

 but, being prevented by want of leifure from purfuing thefe 

 refearches at prefent, I have confined myfelf to eftablifhing 

 the fa6t, and defcribing the proceffes which I have employed. 



Having thus acquired a certainty that mercury is a con- its decompofi- 

 ftituent part of palladium, I made fome further experiments ^'P" ^^'"^^^^^'y 

 upon it, with a view to its analyfis; but they have not been 

 attended with fo much fuccefs. It might be expecled, from 

 tlie great number of methods which have failed to form pal- 

 ladium, that many might be found to decompofe it when 

 formed. But I have found the converfe of fuch proceffes as 

 did not fucceed in producing palladium, to be ineffedual in 

 'deftroying the combination. • • . ' 



Vol, VIT.—February, 1804. H analytical 



