“…Of these, titanium (21), zirconium (22,24), columbium (25) , and plutonium (22) are soluble in all proportions. Ilolybdenum (26,27,28), vanadium (29) and chromium (30) are soluble to the extent of 40, 12 and 4 atom ic percent respectively. Tantalum (31) which usually shows marked similarity to columbium in its chemical and metallurgi cal properties is soluble to only a very limited extent.…”