OSTEO-POEOSIS. 191 



beneatli ; and the loss of structure, however small it might be 

 in the cartilage, extended more or less deeply into the bone ; 

 the size of the cavity increasing with its depth. This fact, I 

 think, proves beyond disputation that the loss of the cartilage 

 depended primarily upon the diseased condition of the bone, 

 and that the general thinning of the cartilage arose from the 

 same cause. Scarcely an articulation of the whole body was 

 free from this ' worm-eaten' condition of both bone and cartilage. 



" It was found likewise, in cleaning the bones after macera- 

 tion, that, from their extreme softness, great care was necessary to 

 prevent their different processes (epiphyses) from being detached, 

 and the application of the slightest force to a portion of ligament 

 or tendon, that was not sufficiently separated by decomposition, 

 would be certain to effect their removal. 



" The external surfaces also of the bones, as contrasted with 

 those in a normal condition, had a very singular aspect, especially 

 in the flat and irregular bones. The ends of the long bones were 

 similarly affected, but the shafts of most of them deviated but 

 little in external appearance from a healthy state. A trans- 

 verse section, however, of the middle of the shaft show^ed very 

 distinctly that the osseous laminse surrounding the Haversian 

 canals were very much tliinner than is natural, thus necessarily 

 leading to a considerable enlargement of the latter. In the first- 

 named, however, and in the flat bones, instead of the surface 

 being smooth and dense, it had a character not very unlike a 

 fine sponge. The foramina for the passage of the blood-vessels, 

 and especially those belonging to the periosteal membrane, were 

 much dilated, thus giving the bone a kind of honeycomb appear- 

 ance." (Figs. 30 and 31 illustrate this peculiar appearance very 

 well.) 



It is found that the weight of the bones is much diminished 

 in osteo-porosis. The articular surfaces undergo changes that 

 are peculiar; thus, in Professor Varnell's cases, the articular 

 cartilage upon one end of the femur was much thinner than 

 is natural, of a dark slate colour in some places, and alto- 

 gether lost in others ; the bone beneath it being very soft, and 

 almost black from congestion of its vessels and extravasation 

 of blood into its interstices. On the other end of the bone, the 

 cartilage was in a different condition, pale in colour, and in 

 some places of a yellowish hue, soft and velvety to the touch. 



