Cerium compounds may be recognized by the red precipitate of ceric hydroxide, which is formed when sodium hypochlorite is added to a colourless cerous salt.
Of the three bromides in common use the potassium salt is the most rapid and certain in its action, but may depress the heart in morbid states of that organ; in such cases the sodium salt - of which the base is inert - may be employed.
In the case of sodium dihydrogen phosphate, NaH 2 PO 4 H 2 O, a stable rhombic form is obtained from warm solutions, while a different, unstable, rhombic form is obtained from cold solutions.
Again, with the solution of a salt such as sodium chloride, the sodium, which is primarily liberated at the cathode, decomposes the water and evolves hydrogen, while the chlorine may be evolved as such, may dissolve the anode, or may liberate oxygen from the water, according to the nature of the plate and the concentration of the solution.
The treatment is the prompt use of emetics, or the stomach should be washed out, and large doses of sodium or magnesium sulphate given in order to form an insoluble sulphate.
The conglomerate consists of rock fragments, sodium chloride and various sulphates, cemented together by gypsum to form a hard compact mass 6 to 10 ft.
These form the principal natural sources of sodium compounds - the chloride as rock salt and in sea-water being of, such predominating importance as quite to outweigh all the others.
A nitride, W2N3, is obtained as a black powder by acting with ammonia on the oxytetrachloride or hexachloride; it is insoluble in sodium hydroxide, nitric and dilute sulphuric acids; strong sulphuric acid, however, gives ammonia and tungstic acids.
This method was followed by that proposed by Gay-Lussac and Thenard, who decomposed molten caustic soda with red-hot iron; and this in turn was succeeded by Brunner's process of igniting sodium carbonate with charcoal.
The crystalline form may be prepared by heating potassium silicofluoride with sodium or aluminium (F.