172 NAVICULARTHRITIS. 



" In the earlier stages of the disease there is deficiency of synovia, 

 but not a total absence of it ; the secreting synovial membrane 

 highly inflamed, &c. — In the advanced stage of the complaint 

 there is a total destruction of the joint, which is so completely 

 disorganized that it can no longer act as a joint. There is 

 not a drop of synovia to he found in it.'' This constitutes what is 

 called the dry state of joint; and it seeins like a remarkable 

 occurrence in a bursal cavity — which the navicular joint in reality 

 is ; it being so well known that inftainmatory action in hursce is 

 commonly productive of augmented secretion of synovia, as is 

 instanced in the capped hock, the windgall, &c. For my own 

 part, however, I do not regard this deficiency of synovia in the 

 navicular joint as an anomaly to the general law of articular in- 

 flammation. I very much doubt that in the earliest stages of navi- 

 cularthritis the synovial secretion is diminished; I should rather 

 feel inclined to think it was augmented, although it may be ex- 

 tremely difficult to produce demonstrative proof either of one state 

 or the other in that incipient stage of the disease which alone could 

 turn out satisfactory. 



As, however, the disease in the joint advances, and ulceration 

 comes to destroy, or interstitial deposition to change, the secretory 

 structure of the synovial membrane, the secretion, of course, would 

 become scanty, and even wanting altogether ; and this I suspect 

 to be the history of the dry navicular joint; and not, as I said be- 

 fore, anything different in the inflammatory action from what hap- 

 pens, under like circumstances, in other joints and bursal cavities. 



Ulceration of the Cartilage speedily follows, if it be not 

 simultaneous in its appearance with, the inflammatory action. It 

 must be remembered that the synovial membrane clothing the ar- 

 ticular cartilages is of that tenuous character that its existence 

 upon such parts was for a long time disputed ; and that no sooner 

 is it attacked with inflammation, than from its low degree of vitality, 

 it, or rather the cartilage underneath it, falls into a state of ulcera- 

 tion; and it is the most prominent point of the cartilage, the part 

 most remote from the source of circulation, which is the first to 

 fall into this state : likewise, the same may be said of the hollowed 

 central point of the cartilaginous capsule of the tendon opposite. 



