THE PROGRESS OF SCIENCE. 



477 



first disappeared. The supposition is 

 that the helium is the product of the 

 atomic decomposition of the radio- 

 active gas. It may be argued that the 

 experiments only prove that radium is 

 not an element, but only a compound 

 of staple elements. On the other hand, 

 the production of this radioactive gas 

 is not influenced by changes of tempera- 

 ture, which is true of no chemical pro- 

 cess, and is accompanied by radioac- 

 tivity, which is not a phenomenon of 

 chemical changes. 



examined contained one eleven-hun- 

 dredth as much radium as pitchblende, 

 the ore from which radium is extracted. 

 Radium salts are found to give off heat 

 at a very considerable rate. M. Curie 

 estimates that radium can melt its 

 weight of ice in an hour. A more ex- 

 act investigation by Rutherford and 

 Barnes shows that the radioactive gas 

 and the secondary activity are the 

 chief sources of the heating effect. 



The treatment of certain diseases, 

 particularly of cancer and lupus, by 



M. AND Mme. Cukie in theik Labokatory. 



The wide distribution of radioactive 

 matter has been brought to light by 

 the work of Professors Elster and 

 Geitel in Germany on the radioactivity 

 of the atmosphere and soils, and by a 

 number of observers under the leader- 

 ship of Professor J. J. Thomson on the 

 presence of a radioactive gas in many 

 spring and well waters. Elster and 

 Geitel discovered that clay is much 

 more active than other soils, appar- 

 ently from the presence of a trace of 

 radium, though much depends on the 

 locality. A certain clay which they 



means of radium radiation continues 

 to attract much attention from physi- 

 cians both in this country and in 

 Europe. A committee appointed by the 

 Vienna Academy of Science to investi- 

 gate the results of the treatment of 

 cancer with radium reported that in 

 nine cases in which the treatment was 

 used abatement in the cancerous swell- 

 ing resulted and in two of these cases 

 the swelling had not reappeared after 

 tive months' time. A case of cancer 

 of the palate was much improved by 

 the treatment. The use of radium is 



