262 SKELETON. 



most valuable on all occasions, affords support to my own. 

 Some years ago I had an opportunity of investigating, some- 

 what fully, this point, in a subject, all of whose large joints were 

 in a state of inflammation. 



These synovial capsules, or membranes, are white, thin, se- 

 mi-transparent, and soft. Wherever there is a deficiency of 

 capsular ligament, they adhere to the contiguous cellular sub- 

 stance, and are so blended with it as to appear absolutely con- 

 tinuous. Dissection, inflation, and maceration, prove them to be 

 laminated, and develop their structure in such a way that it re- 

 solves itself into a cellular tissue, the more interior layers of 

 which had been in a very compacted state. In all this they re- 

 semble the serous membranes, generally, and are ranked among 

 them; Bichat, therefore, considers them only as an interlace- 

 ment of absorbents, and of exhalents. But, for the farther ex- 

 position of this point, see the article on the Serous Membranes. 



The synovial sacs have, on their outer surface, but projecting 

 into the cavity of the joint, adipose cushions of different sizes, 

 called the Synovial Glands of Havers, from which, till lately, it 

 was supposed that the lubricating liquor of the joints is exclu- 

 sively secreted. These cushions have their projecting margins 

 fringed and unusually vascular, and occupy the small spaces 

 left between the articular faces of the bones. As they are co- 

 vered by the synovial membrane, they no doubt assist in the 

 secretion of the synovia. 



The moveable articulations are all furnished with the fluid 

 called Synovia; this name was given to it by Paracelsus, from 

 its resemblance to the albuminous part of an egg, to the con- 

 sistence and colour of which it has a close affinity, and, like it, 

 is thick, ropy, and somewhat yellowish. The chemical analysis 

 of it indicates the presence of water, albumen, and a kind of in- 

 coagulable mucus. It was once supposed to be a mixture of 

 serum, with the adipose matter of the bones, which found its 

 way into the joints by transudation; but as it contains upon ex- 

 periment no oil, the opinion is evidently erroneous. It is se- 

 creted from the whole internal surface of the synovial mem- 

 brane, and, perhaps, in greater quantities from the fringed fatty 



