It also shows a faint yellow line.
The colour of the flame (a crimson) is characteristic.
The reactions of the lithium compounds lie between those of the alkalies
and of the alkaline earths. Solutions are not precipitated by tartaric
acid nor by platinic chloride. The oxide is slowly soluble in water.
The carbonate is not freely soluble. Lithia is completely precipitated
by sodic phosphate, especially in hot alkaline solutions.
In its determination the mixed alkaline chlorides obtained in the
separation of the alkalies are dissolved in water, a solution of soda is
added in slight excess, and the lithia precipitated with _sodic_
phosphate. Before filtering, it is evaporated to dryness and extracted
with hot water rendered slightly ammoniacal. The residue is transferred
to a filter, dried, ignited, and weighed. The precipitate is lithium
phosphate (3Li_{2}O, P_{2}O_{5}), and contains 38.8 per cent. of lithia.
The separation of lithia from magnesia is not given by the usual
authorities. Wohler recommends evaporating the solution to dryness with
carbonate of soda. On extracting the residue with water, the lithia
dissolves out and is determined in the filtrate. One hundred parts of
water dissolve, at the ordinary temperature, 0.769 parts of lithium
carbonate (Li_{2}CO_{3}); the basic magnesia compound is almost
insoluble in the absence of carbon dioxide and ammonium salts.
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