26 OSSEOUS TISSUE. 



(according to Valentin), so also in osteophyte, there is more carbo- 

 nate of lime than in those products which are more similar to 

 osseous tissue. No attempt has been made to ascertain whether 

 in the early stage the cartilage yields chondrin on boiling, as is the 

 case in callus and bones previous to ossification ; but gelatigenous 

 cartilage is contained in perfectly ossified osteophytes. 



The analyses of exostoses lead to the same conclusions as those 

 of osteophytes (Lassaigne). 



Osteoporosis, which is a dilatation of the medullary cells, and of 

 the Haversian canals, may also be the result of inflammation of 

 the bones, since the exudation that is deposited induces a resorp- 

 tion of the lamellae, and consequently a rarefaction of the tissue. 

 But, according to Rokitansky, osteoporosis may also result from 

 excessive development of the medulla, which then penetrates the 

 canals, dilates the cavities, and thus increases the volume of the 

 affected bone. Finally, osteoporosis may arise in consequence of 

 old age or of certain dyscrasice (arthritis, syphilis, &c.,) through 

 simple atrophy with resorption of the lamellae surrounding the 

 canals, and it then yields an extremely brittle product (osteopsa- 

 thyrosis). In the chemical investigation of bones that have under- 

 gone rarefaction (or expansion) these three conditions must not be 

 overlooked ; in all previous investigations, however, little or no 

 attention has unfortunately been paid to these differences. 

 Analyses of porous bones have shown nothing beyond the fact that 

 in general the resorption of the mineral matters of the bones, even 

 in osteoporosis, proceeds more abundantly than that of the carti- 

 lage, and that the cavities which have been produced are filled 

 sooner or later with fluid fat. It has been inferred from these 

 analyses, that the carbonate of lime is resorbed in relatively larger 

 quantities than the phosphate ; but it is only in a few analyses that 

 this relation is perceptible, and in these, the nature of the osteo- 

 porosis affecting the bone is doubtful. Glutin has been found in 

 the cases in which the cartilage of such bones was examined for 

 gelatin, and consequently the chemical constitution of the organic 

 substance remained unchanged. 



In a chemical point of view, osteomalacia has been more inves- 

 tigated than osteoporosis ; but here we must distinguish between 

 the osteomalacia of childhood, that is to say, rachitis, and the 

 softening of the bones in adult life. Yet, notwithstanding the 

 analyses of March and,* von Bibra,f Davy, and Ragsky, to which I 



Journ. f. prakl. Chem. Bd. 27, S. 92. 

 t Op. cit. p. 291. 



