ITS COMPOSITION IN DISEASES. 25 



or even analogous. Thus it is easy to form a conception of osteo- 

 poroses whose origin might be dependent on such different morbid 

 affections that according to the different diseased condition from 

 which they arose, they must have a thoroughly different chemical 

 composition, although morphologically they might be extremely 

 similar. This is shown in a certain degree by the analyses which 

 we at present possess of osteoporotic bones, although these investi- 

 gations are far from being altogether satisfactory ; and seems most 

 decidedly established in the case of caries. Adopting the view 

 held by morbid anatomists, that inflammation of the bones ter- 

 minates in hypertrophy, we have three kinds of hyperostoses to 

 consider, which morphologically, and in part also chemically, differ 

 from one another, namely, primary sclerosis, osteophyte, and 

 exostosis. 



We possess two analyses, made by Ragsky, of primary sclerosis, 

 whose occurrence is generally supposed to depend upon the 

 gradual conversion into cartilage, and finally into bone, of an exuda- 

 tion within the medullary cavities and the Haversian canals (by 

 which the osseous tissue becomes condensed and almost ivory-like) ; 

 they do not, however, at all indicate an augmentation of the 

 mineral constituents of the bones. Even in true sclerosis there is 

 never an excess of earthy matter in proportion to the organic sub- 

 stance deposited in a bone, and hence, we cannot suppose that in 

 primary sclerosis such an augmentation of the mineral substances 

 should occur. When the exudation is transformed into osseous 

 substance, this newly formed structure must at first contain less 

 mineral matter than true bone, and on this account, as indeed is 

 completely in accordance with the analyses, it happens that we often 

 find a relative diminution of the earthy matters in sclerotic 

 bones as compared with normal osseous tissue. All that we can 

 deduce from our analyses of such bones is, that on the one hand 

 their organic basis differs in no respect from the ordinary gelati- 

 genous cartilage, and that on the other, there is a considerable aug- 

 mentation of the carbonate of lime in proportion to the phosphate. 



As osteophyte is a new formation of osseous substance on the sur- 

 face of bone, its composition must naturally vary very considerably 

 with the length of its existence, that is to say, with the stage of deve- 

 lopment into which it has entered from the period of the original 

 formation of the exudation. In the majority of cases both of 

 puerperal and other osteophytes, it has been found both by Ku'hn 

 and myself, that there has been an excess of organic substance and 

 of carbonate of lime above the normal mean. As in callus 



