Sodium gives an intense and persistent yellow flame; lithium gives a carmine coloration, and may be identified in the presence of sodium by viewing through a cobalt glass or indigo prism; from potassium it may be distinguished by its redder colour; barium gives a yellowishgreen flame, which appears bluish-green when viewed through green glass; strontium gives a crimson flame which appears purple or rose when viewed through blue glass; calcium gives an orange-red colour which appears finch-green through green glass; indium gives a characteristic bluish-violet flame; copper gives an intense emerald-green coloration.
Lithium salts render the urine alkaline and are in virtue of their action diuretic. They are much prescribed for acute or chronic gout, and as a solvent to uric acid calculi or gravel, but their action as a solvent of uric acid has been certainly overrated, as it has been shown that the addition of medicinal doses of lithium to the blood serum does not increase the solubility of uric acid in it.
The atomic weight of lithium was determined by J.
It decomposes water at ordinary temperature, liberating hydrogen and forming lithium hydroxide.
Potassium and lithium have a depressing action upon the nervous system, ammonium salts have a stimulating action, while sodium practically speaking is indifferent.
In concentrated or large doses lithium salts cause vomiting and diarrhoea, due to a gastro-enteritis set up by their action.
The species lepidolite is largely used for the manufacture of lithium and rubidium salts.
The best source of rubidium salts is the residue left after extracting lithium salts from lepidolite, the method of separation being based on the different solubilities of the platino-chlorides of potassium, rubidium and caesium in water (R.
Taking sodium and lithium we find in this way that the lithium lines ought to be double and separated by 7 A.
Rend., 1902, 1 35, P. 73 8) obtained ferrous nitride, Fe3N2, and ferric nitride, FeN, as black powders by heating lithium nitride with ferrous potassium chloride and ferric potassium chloride respectively.