MOLYBDENUM BLUE 24 



pound. Action is reversible. 



3. Blue only obtained in acid solution. 



4. Negative colloid. 



5. Exists as crystalloid also. 



6. Forms cubic crystals fi'om alcohol, and transparent cubes 



bearing face of octahedron from blue filtrate after gel 

 has been precipatcd by NH^Cl. 



7. Insoluble in ether, chlorform, benzene, carbon bi-sulphide 



and acetone. 



8. Soluble in water, absolute alcohol and methyl alcohol. 



9. Formula of hydrogel as obtained from analysis = Moj08, 



H,0. Formula of Blue = Mo308. 



10. Sensitivity of test for tin is 1 part in 1,423,000. 



