Calcarea Phosphorica

1. Pyrophosphoric acid in the vitreous state dissolved in distilled water by drops in lime water until the water acted neutral, the gelatinous deposit dried with filtering paper. Proved in 3d and 30th. Contains several combinations of Phosph. ac .

and Calcarea .

1. Freitag : Calcined bones powdered in diluted sulphuric acid dissolved till saturated, filtered, precipitated by carbonate of ammonia, washed with water. Proved by the Allentown Academy in 3d and 30th. Contains a potency of sulphate of ammonia.

2. Lappe : Pure phosphoric acid prepared from bones, saturated with ammonia till it commences to act on reddened litmus. Standing for several days, it forms a sediment of alumina, ferrum, calcarea, or all that may be contained in it ; it is then filtered,

diluted and a solution of calc. mur. added, which is discontinued before it ceases to precipitate ; it is then washed, filtered, and after drying slightly heated in a platina crucible to drive off the last remains of amm. mur. This was potentized by Lappe and Jenichen, and proved by

Schreter.

1. Beneke : Phosphate of soda and muriate of lime ; the precipitate washed. Contains potencies of natr. mur.

2. Gruner separated a neutral combination by adding to one part calc. acetica one and a half of natr. phosph., washing it well. This never will remove all the acetate of sodium.

3. Cate : Five parts of calcined ox bones, finely powdered, well mixed with six parts of oxalic acid and twenty to thirty of distilled water. After standing, filtered to separate the oxalate of lime. The phosphoric acid decanted and bi- carbonate of soda added till

acid reaction ceased. Evaporated till phosphate of soda crystallized ; a clear solution of pulverized oyster shells in boiling acetic acid till neutral, evaporated and crystallized. Each of the two separately dissolved and solutions mixed, washed or dried. Some acetate of sodium will

remain. The same as Gruner's.