CHABANEAU 69 



Chabaneau's discovery consisted in compressing the platinum sponge while 

 hot at the moment of its formation, and then hammering it several times while 

 at a white heat. Since platinum is infusible at the highest temperature of a 

 furnace, it is easily recognized how difficult it had been to convert the pulverulent 

 metal into an ingot. This infusibility is, however, only relative, since Deville has 

 since succeeded in fusing the metal with the oxygen-hydrogen blowpipe; but this 

 property, added to a resistance to the action of acids equal to that of gold, 

 evidently entitles platinum to rank with the precious (noble) metals. 



It is to be noted that there were two necessary conditions for the 

 preparation of malleable platinum, either of which was useless without 

 the other. First, the metal must be obtained from the ore in a pure con- 

 dition, for unless separated not only from the base metals, but also from 

 the largest part of the other platinum metals, the sponge can not be 

 welded into a malleable mass ; second, while at a high temperature the 

 sponge of pure platinum is easily compressed into a malleable ingot, at 

 low temperatures it has no coherence. Virtually this process, generally 

 attributed to Knight, was in use almost exclusively until the last third 

 of the nineteenth century. 



The king, who spent some of his leisure moments dabbling in science, often 

 came to Chabaneau's laboratory and assisted in his experiments. He was very 

 proud to have such a discovery made in his capital, and caused a commemorative 

 medal to be struck in platinum. He also gave Chabaneau a life pension of 

 2,800 piasters ($3,000), in addition to his annual stipend of 12,000 livres, but 

 the pension was granted only on the express condition of residence in Spain, and 

 was to be forfeited should Chabaneau leave the kingdom. The letters-patent 

 bear the date of 1783, and thus establish the priority of Chabaneau's discovery 

 officially and in an incontestible manner. 



Chabaneau was for some time engaged in preparing large quantities of 

 malleable platinum. Then his patron, Marquess d'Aranda, having been ap- 

 pointed ambassador to France (1787), he was prevailed on to accompany him to 

 Paris, in order to convert under his auspices some of the new metal into orna- 

 ments for the crown. Jeanetty, goldsmith to the court of France and a very able 

 man, had been commissioned for this work, and he sought vainly to discover the 

 process used by Chabaneau. He did, however, discover another method (alloying 

 with arsenic) and employed it with such success that he founded in Paris a 

 manufactory for platinum ware, which prospered down to 1820. At present the 

 method of compression while hot, without alloying, is used, and that of Jeanetty 

 has been abandoned. 



It was only two years after this memoir was written that Deville 

 and Debray perfected the method first proposed by Hare in 1838 of 

 fusing platinum in the flame of the oxygen-hydrogen blowpipe. The 

 memoir is somewhat misleading regarding the process of Jeanty (or 

 Jeanetty), for while it is true that he did for many years manufacture 

 platinum crucibles and other vessels by his method, it was early in the 

 century entirely supplanted by the compression method, and it is doubt- 

 ful if much practical application was ever made of it. 



It is then to Chabaneau that belongs all the honor of having first discovered 

 and employed on a large scale the only method which is in use to-day for pre- 



