OP THE ARTICULATIONS. 395 



bones have become spongy in their whole thickness, and that 

 their tissue, which has become soft and red, may easily be cut 

 with the scalpel. On the other hand, when the disease is ter- 

 minated, and the bones have resumed their hardness and-in- 

 flexibility, the compact substance is found much thicker on 

 the concave side of the curvature than on the opposite side; 

 and when the bone is bent at an angle, the place at which the 

 flexure exists is entirely compact, and the medullary canal is 

 obliterated in it. 



In the adult state, the softening depending upon the same 

 cause, may proceed to the same extent, and even farther: the 

 bones may become soft and pliant (Osteomalacia, seu Mala- 

 cost eon}; they may even acquire all the softness and flexibili- 

 ty of flesh (Osteosarcosis}. At this extreme degree of softness, 

 of which the woman Supiot presented an example so gene- 

 rally known, and in which the bones bend like soft wax, desic- 

 cation diminishes their weight and changes their form; de- 

 coction dissolves them; and their chemical composition is 

 changed* to such a degree that they do not contain more than 

 a few hundredth parts of earthy substance. 



Lastly, it may happen, with, or without the preceding 

 changes, that the animal substance of the bones loses its na- 

 tural tenacity, and these organs, having become brittle, break 

 under the slightest effort. 



622. Morbid accidental productions are also sometimes met 

 with in the bony tissue; tubercles, scirrhus, and the encepha- 

 loid production are not uncommon in them. 



SECTION II. 



OP THE ARTICULATIONS. 



623. The Articulation, Jlrticulas, 'Ap0pa is the joining of 

 the bones. The term comprehends the manner in which they 



* Bostock, in Med. Chir. Trans, vol. iv. Lond. 1813. J. Davy, in Monro's 

 Outlines of Anatomy. 



