538 SCIENCE PROGRESS 



green phosphorescence. Under similar conditions quartz glass 

 shows a fine electric blue colour. 



The rays change oxygen into ozone. Hence all dry radium 

 salts smell strongly of ozone. In water this effect is not 

 produced, hydrogen peroxide being formed instead. Radium 

 salts and its emanation decompose water. The emanation also 

 effects the recombination of hydrogen and oxygen. These 

 phenomena are in all probability produced by the a rays. 



Under the action of /3 rays yellow phosphorus is converted 

 into the red variety, while iodine is liberated in iodoform 

 solutions. Much work yet remains to be done in this branch of 

 the subject. 



Radium rays, like X-rays, produce painful burns. Painful irri- 

 tation is caused, then inflammation lasting from ten to twenty 

 days. The skin finally peels off. The physiological effects of 

 radium emanation have been tried on mice and guinea-pigs. 

 Long exposure to such treatment is in most cases harmful, in 

 some fatal. Radium rays have a beneficial result in the case of 

 ulcerous growths, but do not cure true cancer. Their effects 

 are thus similar to those of X-rays, but they have the advantage 

 that the radium preparation, enclosed in a small tube, can be 

 applied locally. The medicinal effects of many natural waters 

 are supposed to be due to the presence of small quantities of 

 radium emanation. They are slightly radioactive. Artificial 

 waters of exactly the same chemical composition do not possess 

 the same beneficial effect. 



Section 3. — Life of a Radioactive Element 



A typical radioactive element gives rise continually to a 

 radioactive product, together with one or more kinds of rays ; 

 radium gives rise to its emanation, and to a rays. In addition, 

 heat in comparatively large quantity is continually liberated. 



This continuous production of both energy and matter is 

 explained by Rutherford by the assumption that atoms of the 

 parent element are continually being broken down, or 

 disintegrated, into simpler atoms, the heat and rays being the 

 difference in energy-content in the two atomic systems. When 

 guncotton is exploded a complex molecule is broken up into 

 simpler ones, heat and light being also emitted. The two 

 cases are parallel, the one being atomic, the other molecular. 



