138 



NAXrVE ALLOY OF GOLB AND PALLADIUM. 



smali ingots, each stamped on one side with the arras of 

 Portugal, and the inscription Rio das montis, and on the 

 other with a globe. The fineness of each ingot too was 

 marked on it. Among these were two dittering from the 

 others so much in colour, that Mr. Cloud preserved one, 

 weighings oz, 11 dwts, 12 grs, to examine it. The iol- 



Analysed. lowing were the experiments he made. 



Nositver. 1. Nitromuriatio acid was eniployf^d on one portion of the 



ingot, to find whether it contained any silver; and none 

 was discovered. 



No metal easi- 2. Twenty four carats were mixed with 48 carats of fine 



joxidable. gUver, and cupelled with lead, to separate any oxidable 

 fnetal that might be present : but there was no diminution 

 of weight, consequently the alloy contained no metal easily 

 oxidable. 



*^**^^' 3. The fine metals of the preceding experiment were 



flattened between rollers, and subjected to the action of 

 pure nitric acid. The silver and the native alloy mixed 

 with the gold, were dissolved by the acid, which acquired a 

 deep brown red colour. The metal that remained, washed 

 with pure water, and dried by the fire, weighed 22 carats 

 Ij gr, Jt had all the appearance of fine gold. 



Soplatina. 4. The metals not dissolved in the latter experiment were 



subjected to the action of nitromuriatic acid. The whole 

 was dissolved, except a small quantity of silver, which had 

 escaped the action of the nitric acid. The solution was as- 

 sayed with muriate of ammonia, and other tests, from an ex- 

 pectation of finding platina, but no trace of this metal was 

 discovered. The gold thrown down was pure to -y^^-j- 



J^ome other 5. Pure muriatic acid was poured into the metallic solu- 



'"*'"*'• tion resulting from Exp, 3, till the silver \yas completely 



thrown down, and the acid was ip considerable excess. 

 T*Jone of the colouring rnatter was precipitated from the so- 

 lution, which remained red, and did not appear at all 

 changed, notwithstanding the precipitation of the silver. 



From these preliminary experiments it appeared, that the 

 alloy was a compound of gold and some metal capable of re- 

 sisting cupellation, and soluble both iq nitric and nitro- 



yalla^ium, muiidtic lipids, In ?^dopting the following mode of analysis 



evident 



