168 SIR WILLIAM RAMSAY 



that equally skilled operators should arrive at irrecon- 

 cilable results. All that we can now hope for is that 

 when peace once more allows the undisturbed pursuit 

 of experimental investigations, this great problem will 

 be resumed and brought to an incontestable issue. 



This is not the place to describe with any detail the 

 manufacture or properties of radium and its salts, but 

 the general reader may be reminded that radium is 

 found in uraniferous minerals, of which the most 

 important is pitchblende, the oxide U 8 8 . The mineral 

 is, however, very complex, containing small quantities 

 of many metals. In the process of separating the minute 

 quantity of radium present in the mineral, advantage is 

 taken of the fact that the salts of radium closely resemble 

 the salts of barium, and that when a solution containing 

 both metals is mixed with sulphuric acid the precipitated 

 barium sulphate carries down with it the whole of the 

 radium also in the form of sulphate. Radium is sold 

 chiefly in the form of bromide, which is still very expen- 

 sive, owing to the demand for scientific and medical 

 purposes and the very limited supply. 



It was Sir Lauder Brunton who first suggested the 

 use of radium emanation as a possible curative agent 

 in cases of cancer. Brunton was a very intimate friend 

 of Ramsay's, the acquaintance dating from early school 

 days. There was therefore a double interest which led 

 Ramsay to take steps in the hope of adding to the 

 limited quantity available for the use of the medical 

 profession in this country. When the emanation was 



