At the Canonsburg plant, two hundred men are neces- 
sary to carry through all the detailed work. 
When this ore is taken up by the Colorado mill, there 
is only one part Radium for every four hundred million 
parts of the ore. 
As this ore reaches the mill at Canonsburg, there is one 
aundred million parts of the ore for every one part of 
Radium. 
The task of the Canonsburg men is to reduce this mass 
of ore to less than a quarter of a ton and to have the Radium 
that may be in the greater mass, in the small residue. 
This is done with regularity and precision, notwith- 
standing that, to eliminate this one hundred million parts 
of undesirable material, this Canonsburg plant has to use 
ten thousand tons of distilled water, a thousand tons of 
coal and five hundred tons of chemicals. 
What small quantity of Vanadium aid Uranium there 
may be in this material, is saved while this reduction is 
being made. 
The actual recovery of whatever Radium there may be 
in the tons of material handled at these two great’ con- 
centration plants, is made elsewhere. When the material 
that reached Canonsburg from the mill in the West has 
been reduced to less than a quarter of a ton, this residue 
is sent to the Radium Research Laboratories of the Com- 
pany in the City of Pittsburgh. 
As it reaches this Laboratory, this material is in the 
form of radium barium chloride. By successive fractional 
erystallizations of the radium chloride, and at a later stage, 
of the bromide, most of the Radium is obtained in a salt 
containing over 95 per cent of pure Radium bromide. 
By further chemical treatment, the bromide is converted 
into the sulphate or the chloride, and in the therapeutic 
ase of Radium, these two salts find the largest use. 
The first Radium produced in the United States was 
obtained in these Radium Research Laboratories of the