THE TENDONS. 361 



The tendons are surrounded by a loose cellular membrane or 

 capsule, which permits them to glide freely upon each other : 

 in some places this membrane is wanting, and is supplied by a 

 synovial membrane answering the same purposes. 



The tendons are readily recognised by their white and shining 

 appearance; they have no elasticity or power of elongation 

 and contraction, and, therefore, like other ligamentous matter, 

 they are lacerated sooner than they can be stretched. They 

 are composed of desmoid tissue, the fibres of which are united 

 by a compact cellular substance in small quantities. The 

 fibres are longitudinal, and may be readily separated either by 

 maceration or by a slight boiling. When a round tendon is 

 prepared in this way, it is easy to flatten it out into an aponeu- 

 rotic membrane : the fibres are then made very distinct, and 

 seem to adhere to each other by lateral fibrillae. In ordinary 

 health no red blood penetrates into the tendons, but if they be- 

 come inflamed, as their capillaries then enlarge, they admit the 

 red globules; at the same time their sensibility, from being en- 

 tirely organic, or what is only sufficient for the internal actions 

 of the organ, is so much augmented as to be very manifest.* 

 No nerves have been traced into them. The tendons have the 

 character, at large, of the desmoid tissue, but are more gela- 

 tinous, or completely soluble in boiling water, than the liga- 

 ments. They have a great affinity for the phosphate of lime ; 

 and, hence, we frequently find them hardened and having small 

 pieces of bone in them, where they run over bony trochleae. 



* A knowledge of the disposition in tendons to augment their powers of circu- 

 lation on being inflamed, together with the late Dr. Physick's great success in 

 the treatment of unnatural joints by a seton passed through the cavity of the 

 fracture, induced me in a late tour of service at the alms-house to try the effect 

 of a similar plan upon a ruptured tendo-achillis; which, from the long period 

 since the accident happened, did not promise a cure on the ordinary principles 

 of treatment. A seton of silk riband was accordingly introduced, and kept in 

 its place for six weeks and a half. It produced considerable pain, tumefaction, 

 and inflammation, but was followed by a perfect reunion of the ruptured ends of 

 the tendon. Chapman's Mod. and Phys. Journal, for July, 1826. For a highly 

 interesting series of experiments on animals, undertaken at my suggestion, to 

 illustrate the same thing, see An Essay for the Degree of Doctor of Medicine, 

 by R. L. Fearn, Id. April 9, 1827. 



VOL. L 31 



