Contact with radium emanation results in a deposit of the fatal radium-D, which in 40 years is but half removed.
The radium emanation is a gas about 111 times heavier than hydrogen; to this gas Sir William Ramsay has given the name niton.
Mix very slowly and quietly in order not to release too much of the radium emanation.
These are generally known as radium emanation, thorium emanation, and actinium emanation.
"He must be using a ray of some sort, possibly a radium emanation," he muttered to himself.
A large quantity of radium emanation was compressed into a fine glass tube A, about 1.5 cm.
Niton, or radium emanation, is one of the products of the disintegration of radium.