LIGAMENTS. 289 



bably to sheaths of cellular substance in the interior, and sur- 

 rounding the tendinous fibres. If we now pour water upon the 

 tendon thus altered, and make it boil, the tendon dissolves ra- 

 pidly, with the exception of the small vessels, which are inter- 

 spersed through it. The solution is similar to one of glue. It 

 is not precipitated by potash nor by prussiate of potash. The 

 same phenomena take place when tendons are treated with mu- 

 riatic acid and by caustic potash. 



When tendons are dried they become hard, translucent, yel- 

 low, and similar to horn ; but they recover their former appear- 

 ance when softened in water. A long maceration in water re- 

 moves the cellular substance, and enables us to separate the ten- 

 dinous fibres from each other. But if we prolong the boiling, 

 these fibres themselves are dissolved and converted into jelly. 



According to the analysis of Mulder and Scherer, the tendons 

 consist of protein combined with three atoms of ammonia, one 

 atom of water, and seven atoms of oxygen. 



The tendons fix the muscles to the bones, and their fibres are 

 interlaced with those of the periosteum, a membrane which seems 

 to possess the same characters as the tendons. At least, like them, 

 it is converted by boiling into gelatin. 



Aponeuroses are a kind of sheaths which inclose one or more 

 muscles, to which they serve as a kind of support, and of which 

 they increase the strength. Their tissue is similar to that of 

 tendons ; they possess both the characters and composition of 

 these bodies. 



CHAPTER XL 



OF LIGAMENTS. 



LIGAMENTS are strong bands which bind the bones together 

 at the joints. Their form and size vary considerably in different 

 parts, some being flat bands, some rounded cords, and others 

 lengthened tubes attached by both ends to bones which admit of 

 free motion on one another, as we see in the capsular ligaments 

 of the hip and shoulder. Most ligaments enter into the forma- 

 tion of joints, and are therefore articular; though some, as the 

 interosseous ligaments in the fore-arm and leg, merely fill up 

 spaces. 



