Palladium and Hydrogenium

[craigy]

another  interesting one from the Royal Mint Museum 

 

The physicist Thomas Graham was Master of the Royal Mint from 1855 to 1869, one of a small number of scientists who ran the organisation, the first being Isaac Newton in the early eighteenth century and the last Thomas Graham himself. What he might have lacked in administrative skill he made up for with his inquisitive mind and, through his investigations into the composition of metals, he generated a series of trial pieces in rather exotic materials.

The half-sovereign size piece illustrated here was produced in 1869 and, as is indicated from the inscription, was the result of experiments into Palladium and Hydrogenium. Unlike his interest in copper alloys, which had a direct effect on the composition of the bronze coinage issued from 1860, it cannot be claimed that these more esoteric investigations had any impact at all on the British coinage. Having carried out the experiments, Graham is known to have given a number of the pieces to friends but, although they were produced at the Royal Mint, he did not see fit to deposit a specimen in the Royal Mint Museum. The example now in the collection was acquired through an unexpected donation from the will of the chemist Sir William Pope.

[secret santa]

Hydrogenium ? Had to Google that one - seems to be another word for hydrogen but I'm pretty sure palladium and hydrogen won't react together.

[VickySilver]

Palladium is a catalyst for chemical reactions and exposure to certain substances will release gasses, etc. including hydrogen (H2) gas

 

[NRP]

I sold one of these around 15 years ago back then it was about £1500, they are extremely rare and would sell for far more now.