22 ADVENTURES IN RADIOISOTOPE RESEARCH 



it by Urbain as a representative of the great French nation which was 

 loyal to us throughout the war. We do not accept the name which was 

 given it by the Danes who only pocketed the spoil after the war." The 

 paper was, however, published by Chemical News without remark. 



Another opposition to the discovery of hafnium came from London. 

 Alexander Scott, the chief chemist of the British Museum, could not iden- 

 tify a fraction of a sample of an Australian titaniferous sand. After our 

 discovery was announced, he thought this fraction to be hafnium. 

 Scott's paper induced the Times to publish in its February 2, 1923, 

 issue an editorial under the title "Hafnium", stating : "Science is, and 

 doubtless should be, international, but it is gratifying that this chemical 

 achievement, the most important since the late Sir Wilham Ramsay 

 isolated helium in 1895, should have been the work of a British chemist 

 in a London laboratory." Scott's sample, sent us for investigation, did 

 not contain a trace of hafnium or zirconium. 



The determination of the hafnium content of a great number of zir- 

 conium minerals and historical zirconium samples was a fascinating 

 task. Berzelius determined the atomic weight of zirconium by analyzing 

 its sulphate. This method supplies too low values for the atomic weight. 

 This error was, however, compensated by the presence of hafnium, almost 

 twice as heavy as zirconium, in his sample. Venable in South Carolina, who 

 spent many years with the determination of the atomic weight of zir- 

 conium, applied a modern method devised by Richards at Harvard. He 

 could not find the reason why his determination led to a clearly too high 

 value. After the discovery of hafnium, he sent us a sample of his zirco- 

 nium, and, after taking into account its quite appreciable hafnium 

 content — which we determined— he could correct the presence of 

 hafnium in his sample and arrive at a precise value for the atomic 

 weight of zirconium. 



Through my work with hafnium I came into contact with the great 

 Austrian chemist Auer von Welsbach. He invested a part of his very 

 substantial royalties obtained for his patent of cerium-iron alloys (applied 

 in cigar-lighters among other things) in a beautiful estate in Carinthia on 

 which he built a castle. The rough crystallization of rare earths was 

 carried out in one of his nearby situated works, and the final crystalliz- 

 ation was done by himself in his castle. He was at that date and for 

 many years to come the only man who possessed highly purified samples 

 of all elements of the rare-earth group. When staying with him, he 

 expressed his astonishment that when separating hafnium from zirco- 

 nium I had chosen to handle large amounts of fluorides, which are highly 

 unpleasant compounds to work with. He achieved all his great success 

 in the field of rare-earth chemistry by crystallizing double- sulfates. We 

 found out later that there is no significant difference between the solu- 

 bility of zirconium and hafnium double- sulfates, and if we had chosen 



