552 TISSUES OF THE CONNECTIVE SUBSTANCE. 



The inorganic constituents of the bony structure, the so-called 

 bone-earths, which, after the complete calcination of the organic sub- 

 stance, remain as a white brittle mass, consist chiefly of calcium and 

 phosphoric acid, but also contain carbonic acid and, in smaller amounts, 

 magnesium, chlorine, and fluorine. Iron, which has been found in bone- 

 ash, does not seem to belong exactly to the bony substance, but to the 

 nutritive fluids or to the other constituents of bones. The traces of 

 sulphate occurring in the bone-ash are derived, according to MORNER, 

 from the chondroitin-sulphuric acid. According to GABRIEL, potassium 

 and sodium are essential constituents of bone-earth, and this has been 

 substantiated by ARON 1 . 



The opinions of investigators differ slightly as to the manner in 

 which the mineral bodies of the bony structure are combined with 

 each other. Chlorine is present in the same form as lin apatite 

 3(Ca3P20s)CaCl2. If we eliminate the magnesium, the chlorine, and 

 the fluorine, the last, GABRIEL claims, occurring only as traces, the remain- 

 ing mineral bodies form the combination 3(Ca3P20s)CaCO3. In his 

 opinion the simplest expression for the composition of the ash of bones 

 and teeth is (CastPO^+CasHPaOis+Aq), in which 2-3 per cent of the 

 lime is replaced by magnesia, potash, and soda, and 4-6 per cent of the 

 phosphoric acid by carbonic acid, chlorine, and fluorine. Recently, on 

 the contrary, GASSMANN has given important reasons for the follow- 

 ing complex combination in WERNER'S 2 sense. 



/OP0 3 Ca\ 



Analyses of bone-earths have shown that the mineral constituents 

 exist in rather constant proportions, which are nearly the same in dif- 

 ferent animals. As an example of the composition of bone-earth we here 

 give the analyses of ZALESKY. S The figures represent parts per thousand: 



1 Morner, Zeitschr. f. physiol. Chem., 23; Gabriel, ibid., 18, which also contains 

 the pertinent literature; Aron, Pfliiger's Arch., 106. 



2 Gassmann, Zeitschr. f. physiol. Chem. 70 and 83; Werner, Ber. d. d. Chem. 

 Gesellsch., 40. 



8 Hoppe-Seyler, Med.-chem. Untersuch., p. 19. 



4 The reports as to the quantity of fluorine disagree; see Harms, Zeistchr. f. 

 Biologic, 38; Jodlbauer, ibid., 41. 



