284 



RICKETS. CARIES. NECROSIS. 



BOOK I. 



chemical theories of disease does not stand the test of even a super- 

 ficial criticism. 



We shall probably form a nearly correct idea of the essential 

 nature of rachitis if we look upon it as a morbid process having its 

 seat in the ossifying epiphyses, and in newly-formed bone a 

 morbid process which is the local expression of a general disorder 

 of nutrition. As a result of the latter, the cartilage cells undergo 

 an abnormal proliferation and the newly-formed bone cells are 

 more or less unfit to separate from the blood the lime salts which 

 are needed for the hardening of the newly-formed ground sub- 

 stance in which they lie. As a result of the excessive proliferation of 

 cartilage cells, the bones enlarge, especially at their epiphyses, and, 

 because as they grow they do not concomitantly harden, they yield 

 to external pressure and become deformed. 



Caries. 



The following is a tabular view of the composition 

 of the bone in caries, according to the analyses of 

 Becquerel and Rodier \ 



Changes in 

 the bone in 

 Caries. 



Changes in 

 the bone in 

 Necrosis. 



von Bibra. 



Collagen 



Necrosis. 



In necrosis the organic matter of bone is gradually 

 removed. 



The following is an analysis 2 of necrosed bone by 



Fats 



Calcium phosphate with) 

 a little calcium fluoride/ 

 Calcium carbonate 

 Magnesium phosphate 

 Soluble salts 



in 100 parts 



19-58 

 1-22 



72-63 



4-03 

 1-93 

 061 



1 Becquerel et Rodier, Traite de Chemie patholoyique, p. 

 3 Quoted by Gantier, Op. cit. Vol. n. p. 543. 



546. 





