THE NEW YORK JOURNAL OF PHARMACY U 



erals. Carnotite was named by Poulot 

 in 1888 in honor of Pres. Carnot of 

 1 ""ranee. 



Poulot found pitchblend in Gilpin Co., 

 Colorado, which he sold to a Roman 

 Catholic Bishop of Denver ; the latter 

 (lied in 1890 and bequeathed it to his 

 successor, who sold it in iot2 to Yale 

 Colleg-e for $10,000. 



To-day botli carnotite ores and pitch- 

 blend are found in Green River district 

 of Utah and the Paradox Valley of 

 Colorado. More than two-thirds of the 

 world's supply of radium is obtained 

 from the ores tf) be found in Colorado. 



The ore is found in pockets in the 

 rocks. 



Carnotite is a lemon yellow mineral 

 usually found in pockets of sandstone 

 deposit; the mineral may be in the form 

 of light yellow specks disseminated 

 through the sandstone or in incrustation •^ 

 in the cracks of the sandstone. It may 

 also appear massive associated with blue, 

 black or brown vanadium ores. 



Pitchblend is a hard blue-black ore. 

 occasionally found with an orange min- 

 eral called gummite. 



The best way of testing these ores is 

 to wrap a photographic plate in the dark ; 

 in two thicknesses of black ])aper lay a 

 key and then just above the key, .suspend 

 two or three ounces of the ore. Place 

 the whole in a light-tight box. After 

 three days develop the plate in the or- 

 dinary way. If the ore is appreciably 

 radio-active, an image of the key will be 

 found on the plate. 



The manufacture of radium consists 

 mainlv in the separation of the iron and 

 other metals held in the ores, together 

 with the rock and the recovery of the 



radium in pure concentrated form or in 

 the shape of radium salts. 



The ore is crushed and placed in large 

 vats into which a solution of sodium car- 

 bonate has been poured; after boiling, 

 the whole is filtered and more sodium 

 carbonate is added to wash out the sul- 

 phate. The liquid is treated with hydro- 

 chloric acid to precipitate the radium and 

 sulphuric acid is added to form radium 

 sulphate which is then changed to a 

 carbonate by adding more sodium car- 

 bonate solution saturated with hydrogen 

 chloride which precipitates only radium 

 and barium chlorides and leaves 

 chlorides of lead, iron, calcium, etc.. in 

 solution. The radium and barium 

 chlorides are practically pure and ready 

 to be separated and crystalized. 



The pure metal is obtained in various 

 ways. One process consists of the con- 

 version of the chloride; i/io of a gram 

 of pure radium chloride is electrolyzed 

 in solution and the radium collected on 

 a mercury cathode. The fluid radium 

 amalgam is dried and then carefully 

 heated in a stream of pure hydrogen 

 gas under reduced pressure. The amal- 

 gam solidifies at 400° C, while 700° C. 

 leaves a residue of metallic radium, the 

 mercurv being completely volatilized. 



Radium or radium salts are generallv 

 carried in specially constructed glass 

 tubes which are then slipped into tubes 

 made of lead. The rays do not penetrate 

 lead as easily and readily as other sub- 

 stances. The market forms consist of 

 radium chloride and radium bromide 

 which are bought and sold on the basis 

 of the metallic radium they contain. 

 The present price is $91,000 per grain 

 of radium chloride and $70,000 per grain 

 of radium bromide. 



