208 CALCIUM PHOSPHATE 



one drachm of opium. For cattle, similar prescriptions are 

 given, frequently in draught. For sheep, the like combina- 

 tions are used, in about one-fourth the dose. For dogs, a 

 convenient pill is made with chalk and ginger, of each grs. x. 

 with opium, grs. ij. ; and aromatic confection, q.s. A 

 draught of similar action is made with chalk, grs. x., lauda- 

 num and ether, of each TT[xv., given in a little milk or soup. 

 Any of these prescriptions may be repeated several times 

 daily. Where it is sought to act chiefly upon the stomach, 

 such medicines are fittingly given dissolved in starch solu- 

 tion as prepared by the laundress, or in spirits and water, 

 administered, according to circumstances, either hot or cold. 

 Where the effects are to be extended throughout the intes- 

 tines, the drugs are generally given in the solid form. For 

 dyspeptic and diabetic horses suffering from acidity, a piece 

 of chalk should be placed in the rack or manger, or in the 

 drinking water. 



CALCIUM PHOSPHATE. Calcii Phosphas. Phosphate of 

 Lime. Ca 3 (P0 4 ) 2 . 



Calcium phosphate is prepared by roasting bone ash until 

 animal and carbonaceous matters are removed, dissolving 

 the residue in diluted hydrochloric acid, precipitating the 

 phosphates by ammonia solution, and washing. Thus puri- 

 fied, it is a light, tasteless, white, amorphous powder, in- 

 soluble in water, but soluble without effervescence in hydro- 

 chloric and nitric acids. 



ACTIONS AND USES. Calcium phosphate is present in bones, 

 nerves, and other animal textures ; occurs abundantly in the 

 intercellular fluid, and wherever cell-growth is most active ; 

 and is hence an essential constituent of food. Its absence 

 in the dietary is shown by Chossat to induce softening of the 

 bones and general wasting ; it is deficient in the bones of 

 pregnant animals. Milne-Edwards found that, when sup- 

 plied to dogs whose bones had been intentionally fractured, 

 more rapid union occurred. 



From its local salt-action, and the soothing effect of the 

 deposition of an insoluble calcium salt, it is specially useful 

 in chronic diarrhoea, anaemia, and other forms of mal- 



