PHOSPHATE OF LIME. 



33 



III. PHOSPHATE OF LIME has been termed bone earth, 

 from its hardening osseous tissue, though found in various 

 other parts of the body. Robin and Verdeil state the quan- 

 tity of this essential principle to be, in 1000 parts of the 

 following substances: 



Enamel . . . 885 Muscles . . .2.5 

 Dentine . . .643 Blood . . . .0.3 

 Bones . . . 550 Gastric juice . . 0.4 

 Cartilages . . .40 



Phosphate of lime is readily absorbed by milk, and exists 

 in solution in the blood. It is deposited in solid tissues, 

 where it combines intimately with the 

 animal basis of the structure, and from 

 which it can be separated by macera- 

 tion in dilute hydrochloric acid, so that 

 a bone may in a short time be twisted 

 in any direction, and turned into a knot, 

 as represented at Pig. 9. 



Phosphate of lime is a crystallizable 

 salt, but it is not in this form that it is 

 met with in bones in which it would 

 appear that the presence of fluoride of 

 calcium prevents crystallization. 



Phosphoric acid, not only in combina- 

 tion with lime, but free, is a most im- 

 portant element in the animal economy. 

 Possessed of powerful chemical affini- 

 ties, this remarkable acid exists in the Fi s- 9 : 

 blood and the tissues only to contribute to their integrity and 

 healthy state, whereas, without the body, it is dangerous to 

 animal life. 



Phosphate of magnesia is always in conjunction with 

 phospL.ate of lime, and alkaline phosphates of soda and potash 



