ON THE FOOT 143 



the disease of the navicular joint : — First, inflammation 

 attacks the membrane lining the joint, succeeded by a 

 diminution of the synovia, and a general stoppage 

 to the healthy secretion of the parts. The consequence 

 of this is increased friction, succeeded by abrasion of 

 the delicate and highly sensible membranes of which 

 they are composed. Secondly, absorption from the 

 centre of the bone takes place, causing a hole in it 

 very similar to that which we see in a carious tooth ; 

 and, lastly, a strong adhesion of the tendon to this 

 hole, forming a disease the most prevalent, and at the 

 same time the most formidable to which the horse 

 is liable. In slight cases I found there had only been 

 an absorption of the cartilage which covers the bone, 

 without any loss of, or hole in, the bone itself, and 

 then there was little or no adhesion of the tendon 

 to the bone. 



Now to aU those who have experienced the painful 

 and distressing effect of a small bone spavin in a horse, 

 it must at once be obvious that to create action in a 

 joint in the state above described must be the cause 

 of excessive suffering to the animal ; yet such is the 

 case with all groggy horses. 



Of the extreme sensibility of joints we need no 

 further proof than to be told that the most trifling 

 exposure of their cavities very often terminates fatally, 

 by excessive irritation. Even bones cannot rest or 

 move upon each other with impunity, but are protected 

 by ligaments which surround their joints, and by a fine 

 vascular membrane which lines their different cavities. 



Whatever may be the credit due to Mr Turner 



