Show erich eiler biler of heidelberg germany has a patent S no for cheaply concentrating radioactive radio active substances radium salts polonium salts etc are for the most part absorbed when they are treated in solution with inorganic colloids coll such as colloidal peroxide of manganese colloidal acid colloidal of arsenicos arse arsenic nicor or with organic colloids coll with a colloid which may be evaporated without residue such as acid as fluoride arsenic as etc the ahe radioactive radio active substances will be left as a residue in concentrated cent rated form ignition will serve to remove organic colloids coll such as gelatin if they be used |