FLUID MAGNE′SIA

Syn. Liquor Magnesiæ carbon at is , L. M. BICARB ON AT IS , L. The preparations sold under this name are mere solutions of freshly precipitated carbonate of magnesia in water, formed by means of carbonic acid gas, under powerful pre ure, and long agitation. Those best known are Sir J. Murray’s and Mr Dinneford’s, each fl. oz. of which is said to contain about 17 1 ⁄ 2 gr. of the carbonate, but their actual richne in the latter seldom exceeds 10 or 12 gr., and by the time they reach the consumer is often as low as 5 or 6 gr. Recently precipitated carbonate of magnesia placed in a bottle or other suitable ve el, which is then filled by means of a soda-water apparatus with water fully charged with carbonic acid gas, readily di olves on slight and cautious agitation, and the aërated water becomes saturated with magnesia. A scruple of carbonate of magnesia put into a soda-water bottle, and thus treated, is all taken up in from 20 minutes to half an hour, and the beverage continues beautifully clear.