Calcium Hypophosphite

CaP 2 H 4 O 4 . Mix milk of lime (1 in 5) in porcelain capsule placed in a sand bath, with half its weight of phosphorus in small pieces, and heat it to ebullition, operating in the open air or under a chimney with a good draught. Spontaneously inflammable phosphuretted hydrogen is given off, the vapour of which should be avoided. Add from time to time a little warm water, to replace that which has evaporated. Discontinue the heat when the phosphorus has disappeared—that is, when inflammable bubbles cease to be produced. If the phosphorus remain in exce , add more milk of lime, and continue the heat until the complete disappearance of the metalloid. Allow the liquor to cool and then filter; then saturate it with a current of carbonic acid gas to eliminate any exce of lime remaining uncombined. Filter again, and concentrate the liquor in a water bath to dryne , keeping the temperature below 100° C., to avoid detonations. Preserve the salt from the air in well-closed bottles. From ‘Formulæ for New Medicaments adopted by the Paris Pharmaceutical Society.’