XXIV 



up the refining business, in which he so largely and successfully engaged. 

 His ability in this (as in all other branches that he entered upon) was soon 

 recognized publicly ; and when the gold bars from the Brazilian Gongo 

 Soco " mines, which came over in very large quantities, were refused at the 

 Mint on account of brittleness, he was consulted on the matter, and under- 

 took to refine and toughen them, in which he perfectly succeeded* 



It was in this gold that he discovered the existence of palladium ; and 

 having succeeded in its separation, he introduced it commercially, at once 

 determining and making known the best uses to which it could be applied. 



After he had been in business some years he visited Germany, and was 

 much interested in mining operations there, to which he gave special atten- 

 tion. It was at this time that he met with the compound alloy called 

 " German silver," then in a very crude state of manufacture. He brought 

 over with him some of the metal, analyzed it, and upon the basis of his 

 analysis he commenced and carried on its manufacture, and introduced it 

 to general use, laying the foundation of the enormous business which has 

 since arisen in this branch of metallurgy. 



About this time he was much engaged in mining pursuits, and was con- 

 sulted upon, and visited professionally, nearly all the mines in England, 

 Wales, Scotland, and Ireland, and many important ones abroad. He was the 

 first to introduce into Cornwall the German shaking-, jigging-, and washing- 

 table, with important improvements of his own. He will always be remem- 

 bered throughout the mining districts for his great kindness and considera- 

 tion toward the miners, whose social condition it was his constant aim to 

 improve. At great expense to himself, he erected schools in the neigh- 

 bourhood of the mines, and took an active part in their supervision. He 

 also used his utmost endeavours to alleviate the toil of the workmen in 

 ascending and descending mines, and with this view he, at the Tamar 

 mines, made the experiment of a sloping gallery, which ran for a consider- 

 able distance under the river, by which means the miners could walk up 

 and down without the use of a ladder. 



Amongst his many inventions of less note may be mentioned several pot- 

 tery colours, amongst them the rose-pink," at a time when that colour 

 was much wanted in the potteries. 



His greatest success, however, and that which has proved the most 

 valuable to the progress of chemistry and manufacture generally, was the 

 platinum business. To him undoubtedly belongs the credit of having been 

 the first who successfully refined and manufactured platinum upon a com- 

 mercial scale, and introduced it for the important purposes to which it is 

 specially adapted. The first large and perfect sheet of pure platinum ever 

 produced was made by Mr. Johnson at 79 Hatton Garden ; and, seeing 

 the immense importance of the metal, he ever since made it his spe- 

 ciality. 



His eminence as an analyst should also be noticed ; so great was it, that 



