1904.] PHILLIPS — RADIUM IN" AN" AMERICAN ORE. 159 



The residual chlorides amounting to two grammes were recovered, 

 and proved to be quite active also ; their activity as compared to 

 uranium was measured by Pegram as 365. 



The radio-activity of the final product could be increased by 

 several fractional crystallizations, when a specimen much less in 

 weight, but more active, would be obtained. 



The radio-activity of the specimen as obtained was deemed 

 sufficiently high to indicate that radium could be produced in 

 quantity from carnotite, at least from this locality, as twenty-five 

 pounds of rather a lean ore had been used. Had a ton been worked 

 over in the same way it would yield a gramme of chlorides of 60,000 

 radio-activity as compared to uranium. This specimen was sepa- 

 rated in November, 1902, and is as active now as then. 



This establishes without doubt the fact that radium salts are 

 dissolved in the acid with which the uranium minerals are treated 

 in the commercial preparation of uranium salts. In the crystal- 

 lization of these salts the radium would be carried in connection 

 with the uranium, as it is in the natural formation of the uranium 

 minerals. This would explain to a certain extent the variable 

 activity of uranium salts, as their activity is not proportional 

 generally to the uranium which they contain. 



Since the separation of this first sample of radium from carnotite, 

 I have received specimens of the mineral from other localities, all 

 of which are active, their activity depending upon the amount of 

 carnotite in the ore. One specimen of quite pure mineral gave an 

 activity of 4, the highest observed in the crude ore. 



A short time ago 3.5 kilos (about eight pounds) were obtained 

 from Montrose County, Colo., selected specimens of which were 

 exposed, in the ordinary way, in making X-ray negatives, with 

 very satisfactory results. 



These photographs show very clearly the bands of active carno- 

 tite separated by the inactive matrix. 



The plates used were Carbutt's B, and exposed to the action of 

 the mineral for sixty hours. With more sensitive plates the same 

 effect could be obtained in much shorter time. 



I am at present at work upon the separation of the uranium, 

 vanadium, and radium salts from these eight pounds of ore as an 

 exhibit at the St Louis Fair. This work is as yet not completed. 



After pulverizing and thoroughly mixing, its radio-activity was 

 measured as 1.71, compared to uranyl nitrate. It was then treated 



