306 Sir James MacTcenzie Davidson [Feb. 2, 



Radium Emanation. — From the radium itself we pass to its eman- 

 ation. The emanation is a heavy gas which can be dissolved in water 

 and be injected into the tissues, or can be confined in a metal tube 

 and buried, the effect being practically the same as with radium 

 itself. The emanation gives us Ih per cent, of the energy which 

 would be obtained if the radium from which it comes were embedded 

 in its stead. The emanation, of course, can also be swallowed in 

 solution and inhaled, and it is now much used in this manner. 

 Several natural waters, such as those of Bath and other spas, contain 

 radium emanation. 



Emanation Effects. — The manifestations of the emanation are 

 much the same as those of the radium itself, and its paralyzing effect 

 upon young animals is practically identical. When introduced into 

 the system by inhalation, by injection, or by swallowing, the emana- 

 tion seems to have a capacity for stimulating the body ferments. 

 This holds true, probably, of many ferment actions in the body, 

 although there are others in which the emanation appears to have no 

 demonstrable influence. The excretion of sugar by diabetics, for 

 instance, is stated to remain unaffected. In a lecture before the 

 Berlin Medical Society, a year ago,* Professor Wilhelm His, after 

 dealing with cases of chronic rheumatism and uric acid gout, a large 

 proportion of which had shown improvement under radium-therapy, 

 said that, in 15 cases out of IS under the influence of the radium 

 emanation, the blood lost its uric acid within a few weeks. He 

 pointed out that emanation behaves like every other gas which is not a 

 normal constituent of the body, and is excreted to a very slight extent 

 through the kidneys and to a large extent by means of the breath. 



[Radium emanation standard.] 



Sir William Ramsay has very kindly given me a " Standard " for 

 the emanation. This little bottle contains 4^^017 ™g- of pure radium. 



Selective Action. — I may be allowed to add a word or two about 

 the action generally of the radium in the body. In the diseases for 

 which the rays possess curative properties their action is extraordi- 

 narily selective, so that, if the dosage is well-timed they destroy the 

 abnormal cells without destroying the normal. To find out in any 

 given case which are the rays to use is an important matter, of 

 course, for investigation, and as knowledge in this direction becomes 

 more precise, the cures that may be set down to radium will be 

 extended and made more certain. 



Other Radio-active Substances. — The great disadvantage in this 

 field of research is the scarcity of radium. As the knowledge of its 

 utility is diffused, the demand for it increases, which seems to indi- 



^ ^January 18,^1911. 



