In the destruction of disease germs the radium emanation has been found more useful than the direct rays. The emanations kill or check the growth of anthrax, typhoid, and diphtheric germs. The direct rays are efficient in the relief of severe cases of enurites and facial neuralgia, cancer, tumors, affections of the skin and abnormal growths. Dr. Guyenot has proved that radium effects a complete cure for rheumatism, which he accounts for in these words: “Uric acid circulates in the blood in the form of urate of soda, of which there are two isomeric forms differing from each other by their respective solubility in the blood plasms. The soluble salt is converted into an insoluble form.” Radium breaks up this compound. The “rheumatism” disappears. CHAPTER VII WHERE WE GET RADIUM The extraction process consists in eliminating the various substances in the ore until only the radium salts are left. But, in the case of carnotite, more than 900 different operations, requiring six months of labor, are required between the digging of the ore and the production of a gram of pure radium salt. A solution containing barium and radium salts in the ratio of ten parts of radium to a billion is treated with sulphate to precipitate an insoluble “raw sulphate of barium.” Radium ores are generally found in connection with granitic masses--_i.e._, in places where granite forms at least part of the rock of the country. The carnotite ore usually consists of a thin layer of sandstone which crops out on the side of a canyon wall and is recognized by the characteristic sulphur-yellow color. The narrow seams are usually in the form of pockets, so that the value of a claim is dubious until it has been thoroughly explored and worked. Most of the original radium minerals, such as uraninite, samarskite, and brannerite, are black and have a shiny fracture and a high specific gravity. These minerals are, however, rarely found in commercially valuable quantities. Pitchblende, the richest source of radium, has the same composition as uraninite and the same general appearance, except that it shows no crystal form. It occurs in veins. There are extensive deposits of pitchblende or uraninite at Joachimstahl, Bohemia (Czecho-Slovakia), containing from 30 to 70 per cent uranium oxide, from which the radium is extracted. But here the uranium ore occurs in small pockets in widely separated localities, so that it is merely a by-product of other mining operations. However, after separation of the uranium from the ore, the residues are three to five times as radioactive, weight for weight, as the uranium. The amount of radium in old unaltered mineral is always proportional to its content of uranium in the ratio of 3.3 parts of radium by weight to ten million parts of uranium.