OF THE ARTICULAR SYNOVIAL CAPSULE. 171 



is owing to the great number of vessels it contains. The sy- 

 novia is partly taken up by absorption, and its quantity in a 

 normal state, being always about the same, supposes an equi- 

 librium between absorption and secretion. 



This liquid known to the Greeks who called it JU|Q tw> apflpw, 

 and long known as axunguia, is viscid and has a saltish taste; 

 its specific gravity is 105, that of water being 100. Its che- 

 mical composition has been examined in animals as well as 

 man, but more particularly in the ox by Margueron, Four- 

 croy, T. Davy, Hildebrandt, M. Orfila and several others. 

 There are found in it water, albumen, mucus or incoagulable 

 matter, considered by some as mucilaginous gelatine, a thready 

 matter, which some think is fibrine and others albumen in a 

 particular state, soda, muriate of soda, phosphate of lime, and 

 an animal matter said to be uric acid. The use of the synovia 

 is to diminish friction and to facilitate thereby the sliding of 

 the parts. 



218. The synovial capsules of the articulations present 

 some pathological alterations.* They are repaired when di- 

 vided; but their mode of reunion is not well understood; 

 there are no precise facts in the history of wounds of the arti- 

 culations, and of luxations, relative to it. New synovial mem- 

 branes are sometimes formed as is observed in false joints, after 

 unreduced luxations; in this case, described by Dr. Thompson 

 and observed by myself, the remains of the old capsule and 

 the cellular tissue united, form a new membrane very similar 

 to the first. In false articulations, which succeed to fractures 

 that have not been consolidated, there is also found a closed 

 membrane, smooth within, containing a viscid liquid more or 

 less analogous to the synovia. 



Dropsy of the joints constitutes hydrarthrosis; in this affec- 

 tion, the synovia undergoes various changes. 



219. Inflammation produces the same alterations of tissue 

 and functions in these, as in the serous membranes generally. 



* See Reimarus, de tumore ligament, etc. Leyd. 1557. Wynpersse, de 

 ancylosi. Leyd. 1783. Ejusd.de ancylpathol Leyd. 1783. Brodie, Traite 

 des maladies des articulations. Paris, 1819. 



