THE TEETH. 



55 



Phosphate of lime and fluoride of calcium .... 5873 



Carbonate of lime 7*22 



Phosphate of magnesia 0*99 



Salts 0-82 



Cartilage 31-31 



Fat 093 



10000 



The earthy salts are readily extracted from the cement 

 by acids, a white cartilage remaining, which may easily be 

 separated from the dentine, and usually, when boiled, yields 

 gelatin. 



Like bone, the cement consists of matrix and of lacuna, but 

 rarely contains Haversian canals and vessels. Besides these, 

 peculiar canals analogous to those of the dentine are found, and 

 other more abnormal cavities. 



The matrix is sometimes granular, sometimes transversely 

 striated, sometimes amorphous, and frequently laminated 



Fig. 192. 



i i/l'iA/rtli W-tL'tiy'M'J't ' "\(1 '''if 



like bone. The lacunae resemble in all essential characters 

 those of the bones, so that any detailed description may be 

 dispensed with. They are distinguished only by the great 

 variety which they present in number, form, and size (0*005 — 

 0-02'", even to 0-03'"), and the unusual number and length 

 (as much as 0-03'") of their canaliculi. The majority are oval. 



Fig. 192. Dentine and cement from the middle of the fang of an incisor tooth : 

 a, dentinal canals; b, interglobular spaces, having the appearance of osseous lacuna; 

 c, smaller interglobular spaces; d, commencement of the cement, with many canals 

 close together; e, its lamella; /, lacuna; g, canals; x 350. From Man. 



