558 TISSUES OF THE CONNECTIVE SUBSTANCE. 



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. 1 The same investigator found that the amount of 

 phosphates is strikingly small in the enamel, and in the teeth consider- 

 able lime is replaced by magnesia. This coincides with BERTZ'S find- 

 ings, that dentin contains twice as much magnesia as the enamel. 



According to GASSMANN, 2 the teeth among themselves have dif- 

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

 substance and richer in lime than the canine teeth. The great tend- 

 ency of the first to caries is probably explained by this fact. The reason 

 for the degeneration of the teeth is considered by C. ROSE 3 to be a lack 

 of earthy salts, and according to him one finds the best teeth in localities 

 where the drinking water has high 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 cel- 

 lular 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 4 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 consists mainly of triglycerides of 

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

 solid kinds of fats, there are glycerides of other fatty acids (see Chapter 

 IV). In all animal fats there are besides these, as FR. HOFMANN 5 has 



1 See footnote 4, p. 552. 



2 Zeitschr. f. physiol. Chem., 55. 



3 Deutsch. Monatsh. f. Zahnheilk., 1908. 



4 Annal. d. Chem. u. Pharm., 142. 



6 Ludwig-Festschrift, 1874, Leipzig. 



