532 TISSUES OF THE CONNECTIVE SUBSTANCES. 



in bone-earths. The quantity of chlorine according to him is remarka- 

 bly high, 0.3-0.5 per cent, while BERTZ l found that the ash of enamel 

 was free from chlorine and that dentin was very poor in chlorine. 



CARNOT, 2 who has investigated the dentin from elephants, has found 4.3 p. m. 

 calcium fluoride in the ash. In ivory he found only 2 p. m. Dentin from 

 elephants is rich in magnesium phosphate, which is still more abundant in ivory. 



GABRIEL found that the quantity of fluorine is very small and amounts 

 to 1 p. m. in ox-teeth. It is no greater in the teeth and enamel than 

 in the bones. 3 The same investigator found that the amount of phos- 

 phates is strikingly small in the enamel, and in the teeth considerable 

 lime is replaced by magnesia. This coincides with BERTZ'S findings, 

 that dentin contains twice as much magnesia as the enamel. 



According to GASSMANN 4 the teeth among themselves have different 

 composition, and in man the wisdom teeth are poorer in organic substance 

 and richer in lime than the canine teeth. The great tendency of the first 

 to caries is probably explained by this fact. The reason for the degene- 

 ration of the teeth is considered by C. ROSE 5 to be a lack of earthy salts 

 and according to him one finds the best teeth in localities where the 

 drinking water has strong permanent hardness. 



IV. THE FATTY TISSUE. 



The membranes of the fat-cells withstand the action of alcohol and 

 ether. They are not dissolved by acetic acid or by dilute mineral acids, 

 but are dissolved by artificial gastric juice. They may possibly con- 

 sist of a substance closely related to elastin. The fat-cells contain, besides 

 fat, a yellow pigment which in emaciation does not disappear so rapidly 

 as the fat; and this is the reason that the subcutaneous cellular tissue 

 of an emaciated corpse has a dark orange-red color. The cells deficient 

 in or nearly free from fat, which remain after the complete disappearance 

 of the latter, seem to have an albuminous protoplasm rich in water. 

 Adipose tissue is rich in a fat-splitting enzyme and in catalases. 



The less water the fatty tissue contains the richer it is in fat. SCHULZE 

 and REINECKE 6 found in 1000 parts: 



Water. Membrane. Fat. 



Fatty tissue of oxen 99 . 7 16.6 883 . 7 



Fatty tissue of sheep 104 . 8 16 . 4 878 . 8 



Fatty tissue of pigs 64.4 13.6 922.0 



The fat contained in the fat-cells chiefly consists of triglycerides of 

 stearic, palmitic, and oleic acids. Besides these, especially in the less 



1 See Maly's Jahresber., 30. 4 Zeitschr. f. physiol. Chem., 55. 



2 Compt. rend., 114. 5 Deutsch. Monatsh. f. Zahnheilk., 1908. 

 * Sec footnote 4, p. 527. Annal. d. Chem. u. Pharm., 142. 



